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Omorogbe Harry







Omorogbe Harry



Chapter One

Introduction and Overview

History and Background

Earlier development and Foundation of the Field


The need for HCI

Strategic Themes

ic Interaction

Direct Manipulation of graphical object

Application Types

Current Development

Technological Trends

Coming Areas

Visualization and Biological Field

Chapter T

Concept and Design in HCI

ign and Evaluation Methods

Concepts of User Interface design

Principle of User Interface Design

Ergonomic Guidelines for User
Interface Design

General Principles to follow when designing any programme

Human Issues

ce of HCI


HCI and Web: pro
blems and Promises

Issues in HCI design in Web Mediun

How screens


Safe Colours

Contributors to HCI

Chapter F

Gesture Recognition

Augmented Reality

Computer Supported Cooperative Work.



Omorogbe Harry





Connecting with your computer

computer interaction and Artificial




"Computer, this is captain Jeanway. Abort the self
destruction sequence. Authorizatio
code, 89453432..."

"Voice, confirmed. Authorization code, confirmed. Abort the self
sequence...Unable to comply, System malfunction..."



If you are a
, you will undoubtly recognize the above conversation. Yes, it is

Star Trek
, a television series spawned by one of the most popular science fiction of the
century. However, if you simply have not heard of "
Star Trek
", do not worry because we
only need to know that the above is a human
computer interaction, which is

hopefully to
happen in the future (except for the "BANG" part). Actually, a conversation as simple as
the above between the human and the computer is far more difficult for today's
technology to accomplish than you may have imagined. It involves speech re
natural language understanding, Artificial intelligence, and natural voice output, all of
which are topics in the study of Human
Computer Interaction (
Simply put,
Computer Interaction is a interdisciplinary study of how humans intera
ct with
computers, which includes user interface design, human perception and cognitive
science, Artificial Intelligence, and Virtual reality.

With the explosive growth of raw
computing power and accompany technologies, computers become essential to everyd
life, and because of this,
, the science of how humans interact with computers is
attracting more and more

these days.

Computer Interaction (
) is the study of how people
design, implement, and use interactive com
puter systems, and how computers affect
individuals, organizations, and society. This encompasses not only ease of use but also
new interaction techniques for supporting user tasks, providing better access to
information, and creating more powerful forms o
f communication. It involves input and
output devices and the interaction techniques that use them; how information is
presented and requested; how the computer's actions are controlled and monitored; all
forms of help, documentation, and training; the too
ls used to design, build, test, and
evaluate user interfaces; and the processes that developers follow when creating


is a research area of increasingly central significance to computer science, other
scientific and engineering disciplines
, and an ever expanding array of application
domains. This more prominent role follows from the widely perceived need to expand
the focus of computer science research beyond traditional hardware and software issues


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to attempt to better understand how techn
ology can more effectively support people in
accomplishing their goals.

At the same time that a human
centered approach to system development is of growing
significance, factors conspire to make the design and development of systems even more
difficult t
han in the past. This increased difficulty follows from the disappearance of
boundaries between applications as we start to support people's real activities; between
machines as we move to distributed computing; between media as we expand systems to
e video, sound, graphics, and communication facilities; and between people as we
begin to realize the importance of supporting organizations and group activities.

Research in Human
Computer Interaction (

has been spectacularly successful,
and has fun
damentally changed computing. Just one example is the ubiquitous graphical
interface used by Microsoft Windows 95, which is based on the Macintosh, which is
based on work at Xerox PARC, which in turn is based on early research at the Stanford
Research Labo
ratory (now SRI) and at the Massachusetts Institute of Technology.
Another example is that virtually all software written today employs user interface
toolkits and interface builders, concepts which were developed first at universities. Even
the spectacula
r growth of the World
Wide Web is a direct result of

applying hypertext technology to browsers allows one to traverse a link across the world
with a click of the mouse. Interface improvements more than anything else has triggered
this explosi
ve growth. Furthermore, the research that will lead to the user interfaces for
the computers of tomorrow is happening at universities and a few corporate research

lecture note

tries to briefly summarize many of the important research
nts in Human
Computer Interaction (
) technology.
By "research," I mean
exploratory work at universities and government and corporate research labs (such as
Xerox PARC) that is not directly related to products. By "

technology," I am
referring to the
computer side of
. A companion work on the history of the "human
side," discussing the contributions from psychology, design, human factors and
ergonomics would also be appropriate.

Figure 1 shows time lines for some of the technologies discussed in t
. Of course,
a deeper analysis would reveal much interaction between the university, corporate
research and commercial activity streams. It is important to appreciate that years of
research are involved in creating and making these technologies rea
dy for widespread
use. The same will be true for the

technologies that will provide the interfaces of

It is clearly impossible to list every system and source in a
lecture note

of this scope, but
I have tried to represent the earliest and m
ost influential systems. Although there are a
number of other surveys of


The technologies covered in this
include fundamental interaction styles like
direct manipulation, the mouse pointing device, and windows; several important kinds

application areas, such as drawing, text editing and spreadsheets; the technologies that
will likely have the biggest impact on interfaces of the
future, such as gesture
recognition, multimedia, Compute

supported Cooperative work, and 3D
; and the


Omorogbe Harry


nologies used to

interfaces using the other

technologies, such as user interface
management systems, toolkits, and interface


Figure 1
: Approximate time lines showing where work was performed on some major
technologies discussed in this ar




HCI is a multidisciplinary field. The main contributions come from computer science,
cognitive psychology, and ergonomics and human factors. However, other areas of
interest include artificial intelligence, (graphic) design, engineering, and e
psychology, sociology, and anthropology:



Omorogbe Harry


: Diagram of contributor to HCI



What we today take for granted were actually the accomplishments of over 30 years of
continuing research in the area. For instance,

Direct Manipulation of graphical objects:
the now ubiquitous direct manipulation interface, where visible objects on the screen are
directly manipulated with a pointing device, was first demonstrated by Ivan Sutherland
in Sketchpad, which was his 1963 MIT

PhD thesis. SketchPad supported the
manipulation of objects using a light

grabbing, moving objects, changing
size, and using constraints. Following that was William Newman's Reaction Handler
which was created at Imperial College, London in
1967. Reaction Handler provided
direct manipulation of graphics, and introduced "Light Handles, " a form of graphical
potentiometer, that was probably the first "widget." Another early System was AMBIT/G
(implemented at MIT's Lincoln Labs, 1968). It employ
ed iconic representations, gesture
recognition, dynamic menus with items selected using a pointing devices, selection of
icons by pointing, and moded and mode
free styles of interaction. Many of the
interaction techniques popular indirect manipulation inte
rfaces, such as how objects and
text are selected, opened, and manipulated, were researched at Xerox PARC in the
1970's. In particular, the idea of "WYSIWYG" (what you see is what you get) originated
there with systems such as the Bravo text

and the

Draw drawing program. The
first commercial systems to make extensive use of Direct Manipulation were the Xerox
Star (1981), the Apple Lisa (1982) and Macintosh (1984). Today, when most people take
for granted the ability of dragging an icon or dropping a
file on their computer, how
many have thought that those are the efforts of 30
year global









and hum




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Major technologies emerged at the same period including Text Editing, The Mouse,
Windows, Gesture recognition and Computer Aided Design, and in most of those f
have made astonishing progresses which we can easily discern today. Among
all facilities working on
, there are a few pioneers that are worth mentioning here.
Xerox PARC is one of the most innovative organizations in the early

earch and
development. It is a major contributor to many important

ideas such as Direct
Manipulation of graphical objects, The Mouse, Windows, etc. MIT AI Lab, IBM, AT&T
Bell lab are also among the most prominent organizations to the early

Because of the collective efforts and contributions from various organizations and
, we were able to

the way humans interact with computers since
1960. However, after 30 years of research, more exciting fields are emergin
g day by day.






one is

encouraged by past research success in

and excited by the
of current research, I
want to emphasize how central a strong research effort is to future
practical use of computational and network te
chnologies. For example, popular
discussion of the National Information Infrastructure (NII) envisions the development of
an information marketplace that can enrich people's economic, social, cultural, and
political lives. For such an information marketpla
ce, or, in fact, many other applications,
to be successful

solutions to a series of significant research issues that all revolve
around better understanding how to build effective human
centered systems. The
following sections discuss selected stra
tegic themes, technology trends, and opportunities
to be addressed by




If one step back from the details of current

research a number of themes are visible.
cannot hope to do justice here to elaborating these or a number of
themes that arose in workshop discussions, it is clear that

research has now started
to crystallize as a critical discipline, intimately involved in virtually all uses of computer
technologies and decisive to successful applications. Here

d on just a few themes:

Universal Access to Large and Complex Distributed Information:

As the "global
information infrastructure" expands at unprecedented rates, there are dramatic changes
taking place in the kind of people who access the available information and the

types of
information involved. Virtually all entities (from large corporations to individuals) are
engaged in activities that increasingly involve accessing databases, and their livelihood
and/or competitiveness depend heavily on the effectiveness and eff
iciency of that access.
As a result, the potential user community of database and other information systems is
becoming startlingly large and rather nontechnical, with most users bound to remain
permanent novices

with respect to many of the diverse informa
tion sources they can
access. It is therefore urgently necessary and strategically critical to develop user


Omorogbe Harry


interfaces that require minimal technical sophistication and expertise by the users and
support a wide variety of information
intensive tasks.

access interfaces must offer great flexibility on how queries are expressed
and how data are visualized; they must be able to deal with several new kinds of data,
e.g., multimedia, free text, documents, the Web itself; and they must permit several

styles of interaction beyond the typical, two
step query
loop, e.g., data browsing, filtering, and dynamic and incremental querying. Fundamental
research is required on visual query languages, user
defined and constr
visualizations, visual metaphors, and generic and customizable interfaces, and advances
seem most likely to come from collaborations between the

and database research

discovery interfaces must support a collaborati
on between humans and
computers, e.g., for data mining. Because of our limited memory and cognitive abilities,
the growing volume of available information has increasingly forced us to delegate the
discovery process to computers, greatly underemphasizing t
he key role played by
humans. Discovery should be viewed as an interactive process in which the system gives
users the necessary support to analyze terabytes of data, and users give the system the
feedback necessary to better focus its search. Fundamental
issues for the future include
how best to array tasks between people and computers, create systems that adapt to
different kinds of users, and support the changing context of tasks. Also, the system
could suggest appropriate discovery techniques depending
on data characteristics, as well
as data visualizations, and help integrate what are currently different tools into a
homogeneous environment.

Education and Life
Long Learning:

Computationally assisted access to
information has important implications for education and

learning as evidenced in
current discussions of "collaboratories" and "virtual universities." Education is a domain
that is fundamentally intertwined with human
computer interaction.

includes both the development and evaluation of new educati
onal technologies such as
multimedia systems, interactive simulations, and computer
assisted instructional
materials. For example, consider distance learning situations involving individuals far
away from schools. What types of learning environments, tools
, and media effectively
deliver the knowledge and understanding that these individuals seek? Furthermore, what
constitutes an effective educational technology? Do particular media or types of
simulations foster different types of learning? These questions
apply not only to


students, but also to adults through life
long learning. Virtually
every current occupation involves workers who encounter new technologies and require
additional training. How can computer
assisted instructional
systems engage individuals
and help them to learn new ideas?

research is crucial to answering these important

Electronic Commerce:

Another important theme revolves around the increasing
role of computation in our economic life and highlights central

issues that go
beyond usability to concerns with privacy, security, and trust. Although currently there is
much hyperbole, as with most Internet technologies, over the next decade
commercialization of the Internet may mean that digital commerce replaces m
traditional commerce. The Internet makes possible services that could potentially be


Omorogbe Harry


quite adaptive and responsive to consumer wishes. Digital commerce may require
dramatic changes to internal processes as well as the invention of new processes. For
gital commerce to be successful, the technology surrounding it will have to be
affordable, widely available, simple to use, and secure. Interface issues are, of course,

User Programming:

An important reason that the WWW has been so
successful is that everyone

can create his or her own pages. With the advent of
WYSIWYG html page
editing tools, it will be even easier. However, for "active" pages
that use forms, animations, or computation, a professional programmer is required to
write the required code in a prog
ramming language like PERL or Java. The situation is
the same for the desktop where applications are becoming increasingly programmable
(e.g, by writing Visual Basic scripts for Microsoft Word), but only to those with training
in programming. Applying the
principles and methods of

to the design of
programming languages and programming systems for end
users should bring to
everyone the ability to program Web pages and desktop applications.

user programming will be increasingly important in the futu
re. No matter how
successful interface designers are, systems will still need to be customized to the needs
of particular users. Although there will likely be generic structures, for example, in an
email filtering system, that can be shared, such systems a
nd agents will always need to
be tailored to meet personal requirements. The use of various scripting languages to meet
such needs is widespread, but better interfaces and understandings of end
programming are needed.

Information Visualization:

This area focuses
on graphical mechanisms designed to
show the structure of information and improve the cost structure of access. Previous
approaches have studied novel visualizations for information, such as the "Information
Visualizer", history
enriched digital objects fo
r displaying graphical abstractions of
interaction history, and dotplots for visualizing self
similarity in millions of lines of text
and code. Other approaches provide novel techniques for displaying data, e.g., dynamic
queries, visual query languages, zo
omable interfaces for supporting multiscale interfaces,
and lenses to provide alternative views of information. Another branch of research is
studying automatic selection of visualizations based on properties o
f the data and the
user's tasks

The importa
nce of information visualization will increase as people have access to larger
and more diverse sources of information (e.g., digital libraries, large databases), which
are becoming universally available with the WWW. Visualizing the WWW itself and
other c
ommunication networks is also an important aim of information visualization
systems. The rich variety of information may be handled by giving the users the ability
to tailor the visualization to a particular application, to the size of the data set, or to
device (e.g., 2D vs. 3D capabilities, large vs. small screens). Research challenges include
making the specification, exploration, and evolution of visualizations interactive and
accessible to a variety of users. Tools should be designed that support a

range of tailoring
capabilities: from specifying visualizations from scratch to minor adaptations of existing
visualizations. Incorporating automatic generation of information visualization with user
defined approaches is another interesting open problem,

for example when the user
defined visualization is underconstrained.



Omorogbe Harry


One fundamental issue for information visualization is how to characterize the
expressiveness of

and judge its adequacy to represent a data set. For
example, the "readabil
ity" of a visualization of a graph may depend on (often conflicting)
aesthetic criteria, such as the minimization of edge crossings and of the area of the graph,
and the maximization of symmetries. For other types of visualization, the criteria are
quite a
d hoc. Therefore, more foundation work is needed for establishing general

Mediated Communication:

Examples of computer
communication range from work that led to extraordinarily successful applications such
as email to that involved in new
er forms of communication via computers, such as real
time video and audio interactions. Research in Computer Supported Cooperative Work
(CSCW) confronts complex issues associated with integration of several technologies
(e.g., telephone, video, 3D graphic
s, cable, modem, fax, email), support for multi
activities (which have particularly difficult interface development challenges), and issues
of security, privacy, and trust.

The unpredicted shift of focus to the Internet, intranets, and the World
ide Web has
ended a period in which the focus was on the interaction between an individual and a
computer system, with relatively little attention to group and organizational contexts.
mediated human communication raises a host of new interface is
Additional challenges arise in coordinating the activities of computer
supported group
members, either by providing shared access to common on
line resources and letting
people structure their work around them, or by formally representing work proces
ses to
enable a system to guide the work. The CSCW subcommunity of human
interaction has grown rapidly, drawing from diverse disciplines. Social theory and social
science, management studies, communication studies, education, are among the relevan
areas of knowledge and expertise. Techniques drawn from these areas, including
ethnographic approaches to understanding group activity, have become important
adjuncts to more familiar usability methods.

Mounting demands for more function, greater avail
ability, and interoperability affect
requirements in all areas. For example, the great increase in accessible information shifts
the research agenda toward more sophisticated information retrieval techniques.
Approaches to dealing with the new requirements

through formal or de facto standards
can determine where research is pointless, as well as where it is useful. As traditional
applications are integrated into the Web, social aspects of computing are extended.



Direct Manipulation of graphical objec

The now ubiquitous direct manipulation
interface, where visible objects on the screen are directly manipulated with a pointing
device, was first demonstrated by Ivan Sutherland in Sketchpad, which was his 1963
MIT PhD thesis. Sketchpad supported the ma
nipulation of objects using a light
including grabbing objects, moving them, changing size, and using constraints. It
contained the seeds of myriad important interface ideas. The system was built at Lincoln
Labs with support from the Air Force and NSF
. William Newman's Reaction Handler,
created at Imperial College, London (1966
67) provided direct manipulation of graphics,


Omorogbe Harry


and introduced "Light Handles," a form of graphical potentiometer, that was probably the
first "widget." Another early system was A
MBIT/G (implemented at MIT's Lincoln
Labs, 1968, ARPA funded). It employed, among other interface techniques, iconic
representations, gesture recognition, dynamic menus with items selected using a pointing
device, selection of icons by pointing, and moded
and mode
free styles of interaction.
David Canfield Smith coined the term "icons" in his 1975 Stanford PhD thesis on
Pygmalion (funded by ARPA and NIMH) and Smith later popularized icons as one of
the chief designers of the Xerox Star. Many of the interact
ion techniques popular in
direct manipulation interfaces, such as how objects and text are selected, opened, and
manipulated, were researched at Xerox PARC in the 1970's. In particular, the idea of
"WYSIWYG" (what you see is what you get) originated there
with systems such as the
Bravo text editor and the Draw drawing program. The concept of direct manipulation
interfaces for everyone was envisioned by Alan Kay of Xerox PARC in a 1977 article
about the "Dynabook". The first commercial systems to make extens
ive use of Direct
Manipulation were the Xerox Star (1981), the Apple Lisa (1982) and Macintosh (1984).
Ben Shneiderman at the University of Maryland coined the term "Direct Manipulation"
in 1982 and identified the components and gave psychological foundati

The Mouse

The mouse was developed at Stanford Research Laboratory (now SRI) in
1965 as part of the NLS project (funding from ARPA, NASA, and Rome ADC) to be a
cheap replacement for light
pens, which had been used at least since 1954. Many of the
current uses of th
e mouse were demonstrated by Doug Engelbart as part of NLS in a
movie created in 1968. The mouse was then made famous as a practical input device by
Xerox PARC in the 1970's. It first appeared commercially as part of the Xerox Star
(1981), the Three Rivers

Computer Company's PERQ (1981), the Apple Lisa (1982), and
Apple Macintosh (1984).


Multiple tiled windows were demonstrated in Engelbart's NLS in 1968.
Early research at Stanford on systems like COPILOT (1974) and at MIT with the
EMACS text editor (1974) also
demonstrated tiled windows. Alan Kay proposed the idea
of overlapping windows in his 1969 University of Utah PhD thesis and they first
appeared in 1974 in his Smalltalk system at Xerox PARC, and soon after in the InterLisp
system. Some of the first commerc
ial uses of windows were on Lisp Machines Inc.
(LMI) and Symbolic Lisp Machines (1979), which grew out of MIT AI Lab projects.
The Cedar Window Manager from Xerox PARC was the first major tiled window
manager (1981), followed soon by the Andrew window mana
ger by Carnegie Mellon
University's Information Technology Center (1983, funded by IBM). The main
commercial systems popularizing windows were the Xerox Star (1981), the Apple Lisa
(1982), and most importantly the Apple Macintosh (1984). The early versions

of the Star
and Microsoft Windows were tiled, but eventually they supported overlapping windows
like the Lisa and Macintosh. The X Window System, a current international standard,
was developed at MIT in 1984.



Drawing programs

Much of the current technology was de
monstrated in Sutherland's
1963 Sketchpad system. The use of a mouse for graphics was demonstrated in NLS
(1965). In 1968 Ken Pulfer and Grant Bechthold at the National Research Council of


Omorogbe Harry


Canada built a mouse out of wood patterned after Engelbart's and us
ed it with a key
frame animation system to draw all the frames of a movie. A subsequent movie,
"Hunger" in 1971 won a number of awards, and was drawn using a tablet instead of the
mouse (funding by the National Film Board of Canada). William Newman's Marku
(1975) was the first drawing program for Xerox PARC's Alto, followed shortly by
Patrick Baudelaire's Draw which added handling of lines and curves. The first computer
painting program was probably Dick Shoup's "Superpaint" at PARC (1974

Text Editing

In 1962 at t
he Stanford Research Lab, Engelbart proposed, and later
implemented a word processor with automatic word wrap, search and replace, user
definable macros, scrolling text, and commands to move, copy, and delete characters,
words, or blocks of text. Stanford'
s TV Edit (1965) was one of the first CRT
display editors that was widely used. The Hypertext Editing System from Brown
University had screen editing and formatting of arbitrary
sized strings with a light pen in
1967 (funding from IBM). NLS demonstra
ted mouse
based editing in 1968. TECO from
MIT was an early screen
editor (1967) and EMACS developed from it in 1974. Xerox
PARC's Bravo was the first WYSIWYG editor
formatter (1974). It was designed by
Butler Lampson and Charles Simonyi who had started wo
rking on these concepts around
1970 while at Berkeley. The first commercial WYSIWYG editors were the Star, Lisa
Write and then Mac Write.


The initial spreadsheet was VisiCalc which was developed by Frankston
and Bricklin (1977
8) for the Apple II while the
y were students at MIT and the Harvard
Business School. The solver was based on a dependency
directed backtracking algorithm
by Sussman and Stallman at the MIT AI Lab.


The idea for hypertext (where documents are linked to related documents)
is credited to Van
nevar Bush's famous MEMEX idea from 1945. Ted Nelson coined the
term "hypertext" in 1965. Engelbart's NLS system at the Stanford Research Laboratories
in 1965 made extensive use of linking (funding from ARPA, NASA, and Rome ADC).
The "NLS Journal" was one
of the first on
line journals, and it included full linking of
articles (1970). The Hypertext Editing System, jointly designed by Andy van Dam, Ted
Nelson, and two students at Brown University (funding from IBM) was distributed
extensively. The University
of Vermont's PROMIS (1976) was the first Hypertext
system released to the user community. It was used to link patient and patient care
information at the University of Vermont's medical center. The ZOG project (1977) from
CMU was another early hypertext sy
stem, and was funded by ONR and DARPA. Ben
Shneiderman's Hyperties was the first system where highlighted items in the text could
be clicked on to go to other pages (1983, Univ. of Maryland). HyperCard from Apple
(1988) significantly helped to bring the id
ea to a wide audience. There have been many
other hypertext systems through the years. Tim Berners
Lee used the hypertext idea to
create the World Wide Web in 1990 at the government
funded European Particle Physics
Laboratory (CERN). Mosaic, the first popu
lar hypertext browser for the World
Web was developed at the Univ. of Illinois' National Center for Supercomputer
Applications (NCSA).

Computer Aided Design (CAD)

The same 1963 IFIPS conference at which Sketchpad
was presented also contained a number of CAD systems
, including Doug Ross's
Aided Design Project at MIT in the Electronic Systems Lab and Coons' work


Omorogbe Harry


at MIT with Sketchpad. Timothy Johnson's pioneering work on the interactive 3D CAD
system Sketchpad 3 was his 1963 MIT MS thesis (funded by the Air F
orce). The first
CAD/CAM system in industry was probably General Motor's DAC
1 (about 1963).

Video Games

The first graphical video game was probably Spaceward by Slug
Russell of MIT in 1962 for the PDP
1 including the first computer joysticks. The early
computer Advent
ure game was created by Will Crowther at BBN, and Don Woods
developed this into a more sophisticated Adventure game at Stanford in 1966. Conway's
game of LIFE was implemented on computers at MIT and Stanford in 1970. The first
popular commercial game was P
ong (about 1976).

UIMSs and Toolkits

The first User Interface Management System (UIMS) was
William Newman's Reaction Handler created at Imperial College, London (1966
67 with
SRC funding). Most of the early work took place at universities (University of Toronto
with Ca
nadian government funding; George Washington University with NASA, NSF,
DOE, and NBS funding; Brigham Young University with industrial funding). The term
UIMS was coined by David Kasik at Boeing (1982). Early window managers such as
Smalltalk (1974) and In
terLisp, both from Xerox PARC, came with a few widgets, such
as popup menus and scrollbars. The Xerox Star (1981) was the first commercial system
to have a large collection of widgets and to use dialog boxes. The Apple Macintosh
(1984) was the first to act
ively promote its toolkit for use by other developers to enforce
a consistent interface. An early C++ toolkit was InterViews, developed at Stanford
(1988, industrial funding). Much of current research is now being performed at
universities, including Garne
t and Amulet at CMU (ARPA funded), MasterMind at
Georgia Tech (ARPA funded), and Artkit at Georgia Tech (funding from NSF and Intel).

There are, of course, many other examples of

research that should be included in a
complete history, including work t
hat led to drawing programs, paint programs,
animation systems, text editing, spreadsheets, multimedia, 3D, virtual reality, interface
builders, event
driven architectures, usability engineering, and a very long list of other
significant developments. Alth
ough our brief history here has had to be selective, what
we hope is clear is that there are many years of productive

research behind our
current interfaces and that it has been research results that have led to the successful
interfaces of today.

r the future,

researchers are developing interfaces that will greatly facilitate
interaction and make computers useful to a wider population. These technologies
include: handwriting and gesture recognition, speech and natural language
understanding, mu
ltiscale zoomable interfaces, "intelligent agents" to help users
understand systems and find information, end
user programming systems so people can
create and tailor their own applications, and much, much more. New methods and tools
promise to make the pr
ocess of developing user interfaces significantly easier but the
challenges are many as we expand the modalities that interface designers employ and as
computing systems become an increasingly central part of virtually every aspect of our


as matured as a discipline, a set of principles is emerging that are generally
agreed upon and that are taught in courses on

at the undergraduate and graduate
level. These principles should be taught to every

undergraduate, since virtually all


Omorogbe Harry


ammers will be involved in designing and implementing user interfaces during their
careers. These principles are described in other publications, such as, and include task
analysis, user
centered design, and evaluation methods.



Again, the number an
d variety of trends identified in

discussions outstrip the space
have here for reporting. One can see large general trends that are moving the field from
concerns about
, as the networked world becomes a reality, to
as app
lications increasingly need to run across different platforms and code begins to
move over networks as easily as data, to issues of
, as we understand the
need to support multiperson and organization activities.
I will

discussion here

a few instances of these general trends.

Computational Devices and Ubiquitous Computing:

One of the most notable
trends in computing is the increase in the variety of computational devices with which
users interact. In addition to workstations and desktop personal

computers, users are
faced with (to mention only a few) laptops, PDAs, and LiveBoards. In the near future,
Internet telephony will be universally available, and the much
heralded Internet
appliance may allow interactions through the user's television and
local cable connection.
In the more distant future, wearable devices may become more widely available. All
these technologies have been considered under the heading of "Ubiquitous Computing"
because they involve using computers everywhere, not just on desk

The introduction of such devices presents a number of challenges to the discipline of
. First, there is the tension between the design of interfaces appropriate to the device
in question and the need to offer a uniform interface for an application a
cross a range of
devices. The computational devices differ greatly, most notably in the sizes and
resolutions of displays, but also in the available input devices, the stance of the user (is
the user standing, sitting at a desk, or on a couch?), the physic
al support of the device (is
the device sitting on a desk, mounted on a wall, or held by the user, and is the device
immediately in front of the user or across the room?), and the social context of the
device's use (is the device meant to be used in a priv
ate office, a meeting room, a busy
street, or a living room?). On the other hand, applications offered across a number of
devices need to offer uniform interfaces, both so that users can quickly learn to use a
familiar application on new devices, and so th
at a given application can retain its identity
and recognizability, regardless of the device on which it is operating.

Development of systems meeting the described requirements will involve user testing
and research into design of displays and input devi
ces, as well as into design of effective
interfaces, but some systems have already begun to address these problems. Some
browsers for the World
Wide Web attempt to offer interfaces that are appropriate to the
devices on which they run and yet offer some un
iformity. At times this can be difficult.
For example, the frames feature of HTML causes a browser to attempt to divide up a
user's display without any knowledge of the characteristics of that display. Although
building applications that adapt their interf
aces to the characteristics of the device on
which they are running is one potential direction of research in this area, perhaps a more
promising one is to separate the interface from the application and give the responsibility


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of maintaining the interface

to the device itself. A standard set of protocols would allow
the application to negotiate the setup of an interface, and later to interact with that
interface and, indirectly, with the user. Such multimodal architectures could address the
problems of gen
erating an appropriate interface, as well as providing better support for
users with specific disabilities. The architectures could also be distributed, and the
building blocks of forthcoming distributed applications could become accessible from
assorted c
omputational devices.

Speed, Size, and Bandwidth:

The rate of increase of processor speed and storage
(transistor density of semiconductor chips doubles roughly every 18 months according to
Moore's law) suggests a bright future for interactive technologies. An importa
constraint on utilizing the full power afforded by these technological advances, however,
may be network bandwidth. Given the overwhelming trends towards global networked
computing, and even the network as computer, the implications of limited bandwidth

deserves careful scrutiny. The bottleneck is the "last mile" connecting the Internet to
individual homes and small offices. Individuals who do not get access through large
employers may be stuck at roughly the present bandwidth rate (28,800 kilobits per
econd) at least until the turn of the century. The rate needed for delivery of television
quality video, one of the promises of the National Information Infrastructure, is 4
megabits, many times that amount. What are the implications for strategic

of potentially massive local processing power t
ogether with limited bandwidth?

Increases in processor speed and memory suggest that if the information can be collected
and cached from the network and/or local sources, local interactive techniques b
ased on
signal processing and work context could be utilized to the fullest. With advances in
speech and video processing, interfaces that actively watch, listen, catalog, and assist
become possible. With increased CPU speed we might design interactive tec
based on work context rather than isolated event handling. Fast event dispatch becomes
less important than helpful action. Tools might pursue multiple redundant paths, leaving
the user to choose and approve rather than manually specify. We can affo
rd to "waste"
time and space on indexing information and tasks that may never be used, solely for the
purpose of optimizing user effort. With increased storage capacity it becomes potentially
possible to store every piece of interactive information that a
user or even a virtual
community ever sees. The processes of sifting, sorting, finding and arranging increase in
importance relative to the editing and browsing that characterizes today's interfaces.
When it is physically possible to store every paper, e
ail, voice
mail and phone
conversation in a user's working life, the question arises of how to provide effective

Speech, Handwriting, Natural Language, and Other Modalities:

The use of speech
will increase the need to allow user
centered presentation of inform
ation. Where the
form and mode of the output generated by computer
based systems is currently defined
by the system designer, a new trend may be to increasingly allow the user to determine
the way in which the computer will interact and to support multiple

modalities at the
same time. For instance, the user may determine that in a given situation, textual natural
language output is preferred to speech, or that pictures may be more appropriate than
words. These distinctions will be made dynamically, based on

the abilities of the user or
the limitations of the presentation environment. As the computing environment used to
present data becomes distinct from the environment used to create or store information,


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interface systems will need to support information a
daptation as a fundamental property
of information delivery.

3D and Virtual Reality:

Another trend is the migration from two
presentation space (or a 2 1/2 dimensional space, in the case of overlapping windows) to
three dimensional
. The
beginning of

this in terms of a conventional presentation
environment is

the definition of the Virtual Reality Modeling Language (VRML). Other
evidences are the use of integrated 3D input and output control in virtual reality systems.
The notions of selecting and inte
racting with information will need to be revised, and
techniques for navigation through information spaces will need to be radically altered
from the present page
based models. Three
dimensional technologies offer significant
opportunities for human
er interfaces. Application areas that may benefit from
dimensional interfaces include training and simulation, as well as interactive
exploration of complex data environments.

A central aspect of three
dimensional interfaces is "near
time" int
eractivity, the
ability for the system to respond quickly enough that the effect of direct manipulation is
achieved. Near
time interactivity implies strong performance demands that touch on
all aspects of an application, from data management through c
omputation to graphical
rendering. Designing interfaces and applications to meet these demands in an
independent manner presents a major challenge to the

Maintaining the required performance in the context of an unpredictable use
environment implies a "time
critical" capability, where the system automatically
gracefully degrades quality in order to maintain performance. The design of general
algorithms for time
critical applications is a new area and a significant chal



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The current development of

is focused on advanced user interface design, human
perception and cognitive science, Artificial Intelligence, and virtual reality, etc.






Why do we always need to type into the computer in
order for it to do something for us?
A very active subfield of

these days is human perception and cognitive science. The
goal is to enable computer to recognize human actions the same way human perceive
things. The focused subfields include

guage and speech recognition, gesture

etc. Natural language interfaces enable the user to communicate with the
computer in their natural languages. Some applications of such interfaces are database
queries, information retrieval from texts and

called expert systems. Current advances
in recognition of spoken language improve the usability of many types of natural
language systems. Communication with computers using spoken language will have a
lasting impact upon the work environment, opening
up completely new areas of
application for information technology. In recent years a substantial amount of research
has been invested in applying the computer science tool of
computational complexity
theory to natural language and linguistic theory, and sc
ientists have found that Word
Grammar Recognition is computationally intractable (NP
hard, in fact)
. Thus, we still
have a long way to go before we can conquer this important field of study.






To realize the ful
l potential of
, the computer has to share the reasoning involved in
interpreting and intelligently filtering the input provided by the human to the computer
or, conversely, the information presented to the human. Currently, many scientists and
ers are involved in developing the scientific principles underlying the reasoning
mechanism. The approaches used varied widely, but all of them are based on the
fundamental directions such as case
based reasoning, learning, computer
instruction, natu
ral language processing and expert systems. Among those, computer
aided instruction (CAI) has its origins in the 1960s too. These systems were designed to
tutor users, thus augmenting, or perhaps substituting for human teachers.
Expert systems
are software

tools that attempt to model some aspect of human reasoning within a
domain of knowledge
. Initially, expert systems rely on human experts for their
knowledge (an early success in this field was MYCIN [11], developed in the early 1970s
under Edward Shortlif
fe. Now, scientists are focusing on building an expert system that
does not rely on human experts.



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From the day we used wires and punch cards to input data to the computer and received
output via blinking lights, to nowadays easy
use, easy
ulate GUI, the
advancement in the user interface is astonishing; however, many novice computer users
still find that computers are hard to access; moreover, even to the experienced user,
current computer interface is still restricting in some sense, that i
s, one cannot

with computers in all the way he/she wants. A complete theory of
communication must be able to account for all the ways that people communicate, not
just natural language. Therefore, virtual reality becomes the

goal of co
interface design. Virtual reality has its origins in the 1950s, when the first video
flight simulator systems were developed for the military. These days, it receives more
and more attention from not only the scientists but the mass population
. (The popularity
of the movie "Matrix" is a demonstration)



Gesture Recognition

The first pen
based input device, the RAND tablet, was funded
by ARPA. Sketchpad used light
pen gestures (1963). Teitelman in 1964 developed the
first trainable gesture recognizer. A
very early demonstration of gesture recognition was
Tom Ellis' GRAIL system on the RAND tablet (1964, ARPA funded). It was quite
common in light
based systems to include some gesture recognition, for example in
the AMBIT/G system (1968

ARPA funded).

A gesture
based text editor using proof
reading symbols was developed at CMU by Michael Coleman in 1969. Bill Buxton at the
University of Toronto has been studying gesture
based interactions since 1980. Gesture
recognition has been used in commercial CAD
systems since the 1970s, and came to
universal notice with the Apple Newton in 1992.


The FRESS project at Brown used multiple windows and integrated text
and graphics (1968, funding from industry). The Interactive Graphical Documents
project at Brown was th
e first hypermedia (as opposed to hypertext) system, and used
raster graphics and text, but not video (1979
1983, funded by ONR and NSF). The
Diamond project at BBN (starting in 1982, DARPA funded) explored combining
multimedia information (text, spreadshe
ets, graphics, speech). The Movie Manual at the
Architecture Machine Group (MIT) was one of the first to demonstrate mixed video and
computer graphics in 1983 (DARPA funded).


The first 3
D system was probably Timothy Johnson's 3
D CAD system
mentioned above (1963,
funded by the Air Force). The "Lincoln Wand" by Larry
Roberts was an ultrasonic 3D location sensing system, developed at Lincoln Labs (1966,
ARPA funded). That system also had the first interactive 3
D hidden line elimination. An
early use was for molecula
r modeling. The late 60's and early 70's saw the flowering of
3D raster graphics research at the University of Utah with Dave Evans, Ivan Sutherland,
Romney, Gouraud, Phong, and Watkins, much of it government funded. Also, the
industrial flight si
mulation work of the 60's

70's led the way to making 3
time with commercial systems from GE, Evans&Sutherland, Singer/Link (funded by


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NASA, Navy, etc.). Another important center of current research in 3
D is Fred Brooks'
lab at UNC.

Virtual Reality and "Augment
ed Reality":

The original work on VR was performed
by Ivan Sutherland when he was at Harvard (1965
1968, funding by Air Force, CIA, and
Bell Labs). Very important early work was by Tom Furness when he was at Wright
Patterson AFB. Myron Krueger's early work

at the University of Connecticut was
influential. Fred Brooks' and Henry Fuch's groups at UNC did a lot of early research,
including the study of force feedback (1971, funding from US Atomic Energy
Commission and NSF). Much of the early research on head
ounted displays and on the
Data Glove was supported by NASA.

Computer Supported Cooperative Work

Doug Engelbart's 1968 demonstration of
NLS included the remote participation of multiple people at various sites (funding from
ARPA, NASA, and Rome ADC). Licklider and Tayl
or predicted on
line interactive
communities in

1968 article and speculated about the problem of access being limited
to the privileged. Electronic mail, still the most widespread multi
user software, was
enabled by the ARPAnet, which became operational

and by the Ethernet from
Xerox PARC in 1973. An early computer conferencing system was Turoff's EIES system
at the New Jersey Institute of Technology (1975).

Natural language and speech:

The fundamental research for speech and natural
language understanding and
generation has been performed at CMU, MIT, SRI, BBN,
IBM, AT&T Bell Labs and Bell Core, much of it government funded. See, for example,
for a survey of the early work.



Now let us take a look of some of the newest developments in




The Intelli
gent room is a project of MIT Artificial Intelligence Lab. The goal for the
project is, said by Michael H. Coen from MIT AIL, is "creating spaces in which
computation is seamless used to enhance ordinary, everyday activities." They want to
incorporate comp
uters into the real world by embedding them in regular environments,
such as homes and offices, and allow people to interact with them the way they do with
other people. The user interfaces of these systems are not menus, mice, and keyboards
but instead ge
sture, speech, affect, context, and movement. Their applications are not
word processors and spreadsheets, but smart homes and personal assistants. "Instead of
making computer
interface for people, it is of more fundamental value to make people
for computers."

They have built two Intelligent Rooms in the laboratory. They give the rooms cameras
for eyes and microphones for ears to make accessible the real
world phenomena
occurring within them. A

of computer vision and speech understand

then help interpret human
level phenomena, such as what people are saying,


Omorogbe Harry


where they are standing, etc. By embedding user
interfaces this way, the fact that people
tend to point at what they are speaking about is no longer meaningless from a
omputational viewpoint and they can then use build systems that make use of the
information. Coupled with their natural interfaces is the expectation that these systems
are not only highly interactive, they talk back when spoken to, but more importantly, t
they are useful during ordinary activities. They enable ta
ks historically outside the
normal range of human
computer interaction by connecting computers to phenomena
(such as someone sneezing or walking into a room) that have traditionally been outsid
the purview of contemporary user
interfaces. Thus, in

the future, you can imagine that

people's homes would call an ambulance if they saw anyone fall down. Similarly,
you can also imagine kitchen cabinets that automatically lock whe
n young childr
approach them.



Scientists are not satisfied with communicating with computers using natural language or
gestures and movements. Instead, they ask a question why can not computers just do
what people have in mind. Out of questions like this, t
here come brain
interfaces. Miguel Nicolelis, a Duke University neurobiologist, is one of the leading
researchers in this competitive and highly significant field. There are only about a half
dozen teams around the world are pursuing the same goals
: gaining a better
understanding of how the mind works and then using that knowledge to build implant
systems that would make brain control of computers and other machines possible.
Nicolelis terms such systems "hybrid brain
machine interfaces" (HBMIs) Rec
working with the Laboratory for Human and Machine Haptics at MIT, he was able to
send signals from individual neurons in Belle's, a nocturnal owl monkey, brain to a robot,
which used the data to mimic the monkey's arm movements in real time.

that Brain
Machine Interfaces will allow human brains to control artificial
devices designed to

lost sensory and motor functions. Paralysis sufferers, for
example, might gain control over a motorized wheelchair or a prosthetic arm, or p
even regain control over their own limbs. They believe the brain will prove capable of
readily assimilating human
made devices in much the same way that a musician grows to
feel that here instrument is a part of his/her own body. Ongoing

in other labs
are showing that the idea is credible. At Emory University, neurologist Phillip Kennedy
has helped severely paralyzed people communicate via a brain

that allows them
to move a cursor on a computer screen. However, scientists still k
now relatively little
about how the

and chemical signals emitted by the brain's millions of neurons
let us perceive color and smell, or give rise to the precise movements of professional

stumbling blocks remain to be overcome b
efore human brains can
interface reliably and comfortably with artificial devices or making mind
prosthetic limbs. Among the key challenges is developing electrode devices and surgical
methods that will allow safe, long
term recording of neurona
l activities.


a look at the future

In conclusion, Human Computer Interaction holds great promise. Exploiting this
tremendous potential can bring profound benefits in all areas of human concern. Just
imagine that one day, we will be able to tell computers t
o do what we want them to do,


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use gestures and hand signals to command them, or directly invoke them through our
thoughts. One day, we will be able to call out an artificial intelligence from the computer
or better yet, a hologram (YES! I am a diehard star
trek fan) to perform the tasks that we
can not accomplish, to solve aid in the emergency situations,
or simply, to have
that can listen to talk to. How bright a future that is shown to as, all thanks for the
research that is going to be done in the

Computer Interaction field.



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Design and evaluation methods have evolved rapidly as the focus of human
interaction has expanded. Contributing to this are the versatility of software and the
downward price and upward
performance spiral, which continually extend the
applications of

The challenges overshadow those faced by designers using
previous media and assessment methods. Design and evaluation for a monochrome,
ASCII, stand
alone PC was challenging, and st
ill does not routinely use more than ad
hoc methods and intuition. New methods are needed to address the complexities of
multimedia design, of supporting networked group activities, and of responding to
routine demands for ever
faster turnaround times.

ore rapid evaluation methods will remain a focus, manifest in recent work on cognitive
walkthrough, heuristic evaluation, and other modifications of earlier cognitive modeling
and usability engineering approaches. Methods to deal with the greater complexit
y of
assessing use in group settings are moving from research into the mainstream.
Ethnographic observation, participatory design, and scenario
based design are being
streamlined. Contextual inquiry and design is an example of a method intended to
obtain a rich understanding of an activity and transfer that understanding to all
design team members.

As well as developing and refining the procedures of design and evaluation methods, we
need to understand the conditions under which they work. Are som
e better for individual
tasks, some excellent for supporting groupware? Are some useful very early in the
conceptual phase of design, others best when a specific interface design has already been
detailed, and some restricted to when a prototype is in exis
tence? In addition, for proven
and promising techniques to become widespread, they need to be incorporated into the
education of UI designers. Undergraduate curricula should require such courses for a
subset of their students; continuing education courses
need to be developed to address
the needs of practicing designers.


All the forms of computer
human interaction discussed here will need to be supported by
appropriate tools. The interfaces of the future will use multiple modalities for input and
output (speech an
d other sounds, gestures, handwriting, animation, and video), multiple
screen sizes (from tiny to huge), and have an "intelligent" component ("wizards" or
"agents" to adapt the interface to the different wishes and needs of the various users).
The tools us
ed to construct these interfaces will have to be substantially different from
those of today. Whereas most of today's tools well support widgets such as menus and
dialog boxes, these will be a tiny fraction of the interfaces of the future. Instead, the too
will need to access and control in some standard way the main application data structures


Omorogbe Harry


and internals, so the speech system and agents can know what the user is talking about
and doing. If the user says "delete the red truck," the speech system needs
access to the
objects to see which one is to be deleted. Otherwise, each application will have to deal
with its own speech interpretation, which is undesirable. Furthermore, an agent might
notice that this is the third red truck that was deleted, and propo
se to delete the rest. If
confirmed, the agent will need to be able to find the rest of the trucks that meet the
criteria. Increasingly, future user interfaces will be built around standardized data
structures or "knowledge bases" to make these facilities
available without requiring each
application to rebuild them.

These procedures should be supported by the system
building tools themselves. This
would make the evaluation of ideas extremely easy for designers, allowing ubiquitous
evaluation to become a ro
utine aspect of system design.

Concepts of User Interface Design




Many people consider the primary criterion for a good user interface to be the degree to
which it is easy to learn. This is indeed a laudable quality of any user interface, but it is
not necessa
rily the most important.

The goal of the user interface should be foremost in the design process. Consider the
example of a visitor information system located on a kiosk. In this case it makes perfect
sense that the primary goal for the interface designe
rs should be ease of operation for the
time user. The more the interface walks the user through the system step by step, the
more successful the interface would be.

In contrast, consider a data entry system used daily by an office of heads
rators. Here the primary goal should be that the operators can input as much
information as possible as efficiently as possible. Once the users have learned how to use
the interface, anything intended to make first
time use easier will only get in the way.

User interface design is not a "one size fits all" process. Every system has its own
considerations and accompanying design goals. The Requirements Phase is designed to
elicit from the design team the kind of information that should make these goals cle




The T
rue Role of Metaphors in the GUI

When the GUI first entered the market, it was heralded most of all for its use of
metaphors. Careful consideration of what really made the GUI successful, however,
would appear to indicate that the use of metaphors was actu
ally a little further down in
the list. Metaphors were really nothing new. The term computer "file" was chosen as a
metaphor for a collection of separate but related items held in a single container. This
term dates back to the very early days of computers

The single most significant aspect of the GUI was the way in which it presented all
possible options to the users rather than requiring them to memorize commands and enter


Omorogbe Harry


them without error. This has nothing to do with metaphor and everything to do wi
focusing the user interface on the needs of the user rather than mandating that the user
conform to the needs of the computer. The visual aspect of the GUI was also a
tremendous advancement. People often confuse this visual presentation with pure
or, but closer inspection reveals that this is not necessarily the case. The
"desktop" metaphor was the first thing to hit users of the GUI. Since it was a global
metaphor and the small pictures of folders, documents, and diskettes played directly into

people bought the entire interface as one big metaphor. But there are significant
aspects of the GUI that have nothing to do with metaphor.

Metaphors vs Idioms

If someone says that a person "wants to have his cake and eat it too," we can intuit the
meaning of the expre
ssion through its metaphoric content. The cake is a metaphor for
that which we desire, and the expectation of both possessing it and consuming it is
metaphoric for the assumption that acquisition of our desires comes at no cost. But if
someone says that hi
s pet turtle "croaked," it is not possible to intuit the meaning through
the metaphoric content of the expression. The expression "croaked" is an idiom. We
know instantly that the turtle didn't make a funny noise but rather that it died. The
meaning of the

idiom must be learned, but it is learned quickly and, once learned,
retained indefinitely.

Most visual elements of the GUI are better thought of as idioms. A scroll bar, for
example, is not a metaphor for anything in the physical world. It is an entirel
y new
construct, yet it performs an obvious function, its operation is easily mastered, and users
easily remember how it works. It is the visual aspect of the scroll bar that

it to be
learned so quickly. Users operate it with visual clues rather tha
n remembering the keys
for line up, line down, page up, page down, etc.

Metaphors Can Hinder As Well As Help

The use of metaphor can be helpful when it fits well into a situation, but it is not a
panacea and is not guaranteed to add value. The use of icons as metaphors
for functions
is a good example. It can be a gamble if someone will understand the connection
between an icon and the function. Anyone who has played Pictionary knows that the
meaning of a picture is not always clear.

Consider the Microsoft Word 5.0 too
lbar. Some icons area readily identifiable, some are
not. The meaning of the identifiable icons will likely be gleaned from the icon, but is still
not a guarantee. The unidentifiable icons, however, can be utterly perplexing, and rather
than helping they c
an create confusion and frustration. And with so many pictographs
crammed into such a small space, the whole thing reads like a row of enigmatic, ancient
Egyptian hieroglyphs.

The Netscape toolbar, by contrast, can be considered to be much more graceful

useful. The buttons are a bit larger, which makes them generally more readable. Their
added size also allows the inclusion of text labels indicating the command to which the
icon corresponds. Once the meaning of each icon has become learned the icon c
an serve
as a visual mnemonic, but until then the text label clearly and unambiguously relays the
function the button will initiate.



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The Netscape toolbar admittedly consumes more valuable window real estate than the
Microsoft Word toolbar does. There are

keystroke shortcuts for every button, however,
and users who have mastered them can easily hide the toolbar from view. Users who
prefer to use the toolbar are probably willing to sacrifice that small bit of real estate in
order to have a toolbar that is p
resentable and easy to use.

The "Global Metaphor" Quagmire

One major pitfall into which metaphors can lead us is the "Global Metaphor," which is a
metaphor that is intended to encompass an entire application. The "desktop" concept is
an example of a global metaphor.

he global metaphor becomes a quagmire when reality begins to diverge from the
metaphor. Consider carefully the desktop metaphor. It can be seen how it deviates from
reality immediately. The trash can is a wonderful metaphor for the deletion function, but
rash cans are generally not situated on the top of a desk.

The use of the trash can to eject a disk is a perfect example of contorting the metaphor to
accommodate the divergence from reality. The expectation is that "trashing" a disk will
delete its cont
ents, yet the interface designers needed a way to eject a disk and the trash
can came closer than anything else. Once learned it becomes an idiom that works fine,
but it is initially counter
intuitive to the point that it is shocking.

The vertical aspect

of the desktop also subverts the metaphor. It's closer to a refrigerator
on which one can randomly place differently shaped magnets, or the old
displays on which TV weathermen placed various symbols. The fact that the desktop
metaphor has to be
explained to first
time users is an indication that it might not be
terribly intuitive.

The global metaphor is an example of the "bigger is better" mentality. Metaphors are
perceived as being useful, so some people assume that the more all
encompassing a

metaphor is the more useful it will be. As in all other situations, the usefulness of a
global metaphor is dictated by the overall goals of the interface. If the goal of the
interface is to present a non
threatening face on a system that will be used prim
arily by
technical first
time users, a global metaphor might be useful. But if the goal of the
interface is to input large quantities of data quickly and effectively, a global interface
might be an enormous hindrance.










le metaphors aren't always as useful as other solutions, it is important to note that in
the right situation they can be a vital part of a quality user interface. The folder is a
particularly useful and successful metaphor. Its purpose is immediately appar
ent, and by
placing one folder inside another the user creates a naturally intuitive hierarchy. The
counterpart in the character user interface is the directory/subdirectory construct. This
has no clear correspondence to anything in the physical world, and

many non
people have difficulty grasping the concept.

The bottom line is that if a metaphor works naturally, use it by all means. But at the first
hint that the metaphor is not clearly understood or has to be contorted in order to


Omorogbe Harry


reality, it should be strongly considered as to whether it will really help or


It is generally perceived that the most fundamental quality of any good user interface
should be that it is intuitive. The problem is that "intuitive" means different thin
gs to
different people. To some an intuitive user interface is one that users can figure out for
themselves. There are some instances where this is helpful, but generally the didactic
elements geared for the first
time user will hamper the effectiveness of

intermediate or
advanced users.

A much better definition of an intuitive user interface is one that is easy to learn. This
does not mean that no instruction is required, but that it is minimal and that users can
"pick it up" quickly and easily. First
me users might not intuit how to operate a scroll
bar, but once it is explained they generally find it to be an intuitive idiom.

Icons, when clearly unambiguous, can help to make a user interface intuitive. But the
user interface designer should never ov
erlook the usefulness of good old
fashioned text
labels. Icons depicting portrait or landscape orientation, for example, are clearly
unambiguous and perhaps more intuitive than the labels themselves, but without the label
of "orientation," they could make
no sense at all.

Labels should be concise, cogent, and unambiguous. A good practice is to make labels
conform to the terminology of the business that the application supports. This is a good
way to pack a lot of meaning into a very few words.

g intuitive user interfaces is far more an art than a science. It draws more upon
skills of psychology and cognitive reasoning than computer engineering or even graphic
design. The process of Usability Testing, however, can assess the intuitiveness of a us
interface in an objective manner. Designing an intuitive user interface is like playing a
good game of tennis. Instructors can tell you how to do it, but it can only be achieved
through hard work and practice with a lot of wins and losses on the way.


sistency between applications is always good, but within an application it is
essential. The standard GUI design elements go a long way to bring a level of
consistency to every panel, but "look and feel" issues must be considered as well. The
use of labels

and icons must always be consistent. The same label or icon should always
mean the same thing, and conversely the same thing should always be represented by the
same label or icon.

In addition to consistency of labeling, objects should also be placed in

a consistent
manner. Consider the example of the Employee Essentials Address Update panels
(available through Bear Access).



Omorogbe Harry


There is a different panel for every address that can be updated, each with its own set of
fields to be displayed and modified.
Note that each panel is clearly labeled, with the label
appearing in the same location on every panel. A button bank appears in the same place
along the left side of every panel. Some buttons must change to accommodate the needs
of any given panel, but pos
itionality was used consistently. The closer buttons are to the
top the less likely they are to change, and the closer to the bottom the more likely.

Note especially the matrix of buttons at the top left corner of every panel. These buttons
are the same
in every panel of the entire Employee Essentials application. They are
known as "permanent objects." Early navigators used stars and constellations as
unchanging reference points around which they could plot their courses. Similarly,
modern aviation naviga
tors use stationary radar beacons. They know that wherever the
plane is, they can count on the radar beacon always being in the same place.

User interface designers should always provide permanent objects as unchanging
reference points around which the u
sers can navigate. If they ever get lost or disoriented,
they should be able to quickly find the permanent objects and from there get to where
they need to be. On the Macintosh, the apple menu and applications menu are examples
of permanent objects. No mat
ter what application the user is in, those objects will appear
on the screen.

Most all Macintosh applications provide "File" and "Edit" as the first two pull
menus. The "File" menu generally has "New" "Open" "Close" "Save" and "Save As" as
the first

selections in the menu, and "Quit" as the last selection. The "Edit" menu
generally has "Cut," "Copy," and "Paste" as the first selections. The ubiquity of these
conventions has caused them to become permanent objects. The users can count on
finding them
in virtually all circumstances, and from there do what they need to do.

Bear Access itself is becoming a permanent object at Cornell. If a user is at an unfamiliar
workstation, all he or she needs to do is locate Bear Access, and from there an extensive
suite of applications will be available.


The complexity of computers and the information systems they support often causes us
to overlook Occam's Razor, the principle that the most graceful solution to any problem
is the one which is the most simple.

A good

gauge of simplicity is often the number of panels that must be displayed and the
number of mouse clicks or keystrokes that are required to accomplish a particular task.
All of these should be minimized. The fewer things users have to see and do in order t
get their work done, the happier and more effective they will be.

A good example of this is the way in which the user sets the document type in Microsoft
Word version 5.0 as compared to version 4.0. In version 4.0, the user clicks a button on
the save
dialog that presents another panel in which there is a selection of radio buttons
indicating all the valid file types. In version 5.0, there is simply a popup list on the save
dialog. This requires fewer panels to be displayed and fewer mouse clicks to be
and yet accomplishes exactly the same task.



Omorogbe Harry


A pitfall that should be avoided is "featuritis," providing an over
abundance of features
that do not add value to the user interface. New tools that are available to developers
allow all kinds of things
to be done that weren't possible before, but it is important not to
add features just because it's possible to do so. The indiscriminate inclusion of features
can confuse the users and lead to "window pollution." Features should not be included on
a user i
nterface unless there is a compelling need for them and they add significant value
to the application.


A fundamental tenet of graphic user interfaces is that it is preferable to prevent users
from performing an inappropriate task in the first place rather tha
n allowing the task to
be performed and presenting a message afterwards saying that it couldn't be done. This is
accomplished by disabling, or "graying out" certain elements under certain conditions.

Consider the average save dialog. A document can not b
e saved if it has not been given a
name. Note how the Save button is disabled when the name field is blank, but is enabled
when a name has been entered.


One of the advantages of graphic user interfaces is that with all the options plainly laid
out for users,

they are free to explore and discover things for themselves. But this
requires that there always be a way out if they find themselves somewhere they realize

shouldn't be, and that special care is taken to make it particularly difficult to "shoot
selves in the foot." A good tip to keep users from inadvertently causing damage is to
avoid the use of the Okay button in critical situations. It is much better to have button