Alternative Input Devices - School of Computing

parisfawnAI and Robotics

Nov 17, 2013 (3 years and 4 months ago)

68 views

Alternative


Input Technologies

Presenter
: John Beckett, DBA


Professor
,
School

of
Computing


Class:
CPIS 210

Overview


“Good” input principles


Physical types of input


Commonly used for MIS


Not (yet) commonly used for MIS


Quality and Security issues


Appropriate Use Issues


Trends / The Future

“Good” Input Principles


Captured as near as possible to the source


Entered using an appropriate method


Verified by people who have an interest in it
being correct


Correctable as early as possible in the chain of
events

PHYSICAL TYPES OF INPUT

COMMONLY USED
FOR IT

Keyboards


Standard “QWERTY”


over 100 years old


Inefficient but “everybody” knows it


Alternative: DVORAK


Multi
-
key boards haven’t made the cut


Touch versus price versus size


IBM
Selectric

is the gold standard (speed & accuracy)


Elastomeric is cheapest and worst



Chicklets
” are deprecated


Small
-
width keys, non
-
moving keys, and multiple
-
strokes slow the process


(
Netbook
, PDA, cell phone)

Pointing Devices


Mouse


Trackball


3
-
D devices


Pens


Touch Screen


Eye trackers



New wave: Kinetic gestures, multiple
-
pointer


Will
iAnything

and Windows agree?

Wireless Warning


Any form of wireless is to some extent
vulnerable to monitoring or meddling or
jamming


Encryption (if it is used) helps


perhaps a
great deal


Never “bind” in an
insecure location

The GUI Question

(Graphical User Interface)

Command/Keyboard
Ctl


Steeper learning curve


Must memorize keyboard
methods



Faster entry




Requires two hands

GUI Control


Easier learning


Unless things get moved
around, wasting users’
investment and discouraging
them


Slower entry


Requires hand
-
eye
coordination


Requires 3 hands


Or lost time going to and
from pointing device

The GUI Solution


Use the GUI method


Learn the short
-
cut keys


Test your users


Provide incentives


Mark Sense


Specific areas on an
input document have
specific meanings


Became mainstream
1936
-
1950


Useful for low
-
tech
environments with
many sources and small
amounts of data


Time cards


Multiple
-
choice tests

40

2

Is High
-
Tech Better?


Case: Optical scanner used in 1974
-
77 to enter classes
for students. 1,800 5
-
digit student IDs with 6 4
-
digit
class numbers in 2 days = 225,000 keystrokes


11 students per minute


Reliability problems due to moving the device to the gym for
Registration, environment


Pilot test showed that 2.5 people could enter on keyboards
just as fast. We implemented 4.


2 people was enough; 4 meant we could relate to customer


After the next year’s experience, we junked the scanner


Take
-
home: New technology is not “better” if it makes
your solution substantially less reliable

Bar Codes

Code 3 of 9


Tighter spec


More expensive to print


Lower first
-
read rate


Higher accuracy


Locally assigned number


Duplication possible

Universal Product Code


Looser spec


Easier to print


Higher first
-
read rate


Lower accuracy


Number assigned by central
agency


No duplication danger

2D Codes



Multiple types in current use

Turnaround Documents

Document printed by system,
then read when client
returns it



Utility Bills (old punched
-
card system)


Airline check
-
in (printed
bar code)


Wal

Mart Site2Store
(printed bar code)

Magnetic Stripes


Usually used on credit card size devices


Requires an encoder


Can’t just use a photocopier to duplicate


Two stripes on one card is
po
$$
ible


Used for two incompatible systems


Proprietary stripes for high security from
Weigand

ID tag/card recording characteristics

Bar Code


Standards: UPC, 3of9



Cost: a penny or less


Can be part of packaging


Easy to duplicate/falsify



Somewhat human
-
readable


Contains up to ~25 chars

Magnetic Stripe


Standards: ABA, Drivers
License


Cost: 10¢
-
up


Applied oxide strip


Requires special machine to
make


Marks invisible to people


Contains up to ~ 100 chars

Interactive Voice Response (IVR)


-
> Voice synthesizer


<
-

DTMF (touch
-
tone) keypad


<
-

Voice recognition



Great way to handle structured customer service (e.g.
prescription refills)


Frustrating for people who would rather talk with a
person


Preferred by people who want simple transactions
24x7


Possible problem: Certain peoples’ throats have
overtones that trigger DTMF
receiverss

Scanning and OCR


Scanning produces a digital picture of a document


OCR (Optical Character Recognition
) software
attempts
to extract text from a document


Challenges:


Font may not be recognized


Layout can confuse the software


Reproduction quality may not be good enough


Rule of thumb: If you plan to publish it, hand
-
keyboarding may be better (less costly at a given
quality point) than OCR

Specialized Methods


MICR (Magnetic Ink Character Recognition)


Used for checks (a dying breed, BTW)


Old technology required magnetic ink


Purely optical methods used nowadays


RFID (Radio
-
Frequency Identification)


Used to detect stolen merchandise


Deactivation actually destroys the transmitter


Far less useful for inventory control


requires
unique ID for each product box


PHYSICAL TYPES OF INPUT

NOT (YET) COMMONLY USED FOR MIS

Contact Smart Cards


Contain a computer and a
small amount of data
storage


Encryption used to keep
Bad Guys from making
unauthorized changes


Requires electrical
connection


Some history of
compromise by hackers

Non
-
Contact Smart
Cards


Reader uses magnetic
induction to provide
power to a computer
on the device


Device links by coded
radio conversation


History of security
problems

Mobil
SpeedPass

Links to bank card account

Hong Kong Octopus Card

(Balance kept on card)

Encryption


Uses mathematical algorithms (transformation) for hiding
information in random
-
looking stream of data


“Strength” of encryption indicated by how many bits are in the key


Effective key length can be multiplied by multiple passes through the
algorithm, e.g. DES3 often used for HIPAA



Buys you time before decryption


Eventually it will be decrypted, if only by brute force


Your protection: Computers are not infinitely fast


That protection is weakening every year


Sometimes people “break” encryption, sharply reducing the time to
decrypt the broken algorithm


HDTV algorithm is broken, but would require a new chip


No guarantee that the algorithm designer did not include a “back
door” so they can get in


With state
-
of
-
art methods, encryption is “good enough”


And necessary!

Infra
-
Red


Light, long wavelength that people cannot see


Useful for small amounts of information such
as controls for TV equipment


Short
-
lived attempt to use for printer
connections


Not reliable enough


Note: Digital cameras can be used to verify
that an IR controller is working

Biometric


Still have relatively high false positive and false
negative error rates compared to digital
objects such as
mag
-
stripe ID cards


Biometrics can be falsified better than most
other ID systems


Fingerprint is better than other biometrics


Primarily useful as an additional dimension in a
security system

Media Input

Audio


Most PCs and Macs have an
audio input jack


PC input jack is specialized,
for a monaural condenser
microphone


Line input jack is available on
desktops as well


Mac input jack is similar to
hi
-
fidelity stereo “line input”


Depends on model

Video


Requires an adapter


Either internal or external


Except in “media” computers,


There are many video
formats and protocols


Not necessarily compatible


Converters (
codecs
) are
available, sometimes for $

Many laptops now contain

microphones & cameras

QUALITY AND SECURITY

Input Data Quality


“First read rate” (false positives & negatives)


Causes of success & failure


Temperature


Contamination


Interference


Physical Disability


Poor design (Mayfield example)


Manual Bypass

Tradeoff Parameters

When considering an input technology, ask about:


Equipment Cost


Media Cost


Connectivity (both hardware and software)


Data capacity


Speed


Quality


Security

APPROPRIATE USE ISSUES

Cost & Durability


Is the unit cost appropriate for the situation?


Will the media hold up over the expected
lifetime?


Will the device survive expected use?


Is it practical to replace broken devices?

Human Factors


Does this person know how to type?


Does the device require socially unacceptable
behaviors?


Fingerprint devices, formerly an issue


Does this device work at an appropriate data
rate?


Does the user have to touch
-
type a lot of data on
an elastomeric or touch
-
screen keyboard?

Security


Can this input device be “sniffed?”


Shoulder surfing (perhaps a shield will help)


Technical devices (need encryption?)



Can input from this device be falsified?


Bar codes can be copied


For money, duplicate magnetic stripes


Biometric devices have been fooled by latex
copies


TRENDS / THE FUTURE

Smart Phones


More
-
than
-
a
-
cellphone

devices are gradually becoming
ubiquitious


Platform proliferation:


iPhone
/iPod/
iPad


Windows CE & friends


Palm


? (Everybody is making one now)


Linux


sorry about this one!


Small form factor: Increased dependence on excellent
human
-
factor design


Combine gesture, typing, voice, and camera (still &
video) input

The
iPhone

Deposit Application

What About the
iPad
?


Looks like an over
-
grown
iPod Touch


Removes screen size
limitation


Leverages existing
technology


Doesn’t fit in a pocket


Might be good for
situations where you are
interacting with a client


Bed
-
side


Casual settings