Data Capture Methods

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17 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

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Data Capture Methods

Data Capture Methods

In this topic, we will be looking at:



Methods of data capture


When it would be appropriate to use each
method


Advantages and disadvantages of each


The concept of encoding

Manual Input

Methods that register movements of the
hand include:



mouse



keyboard



tracker ball



graphics tablet



touch
-
screen


e.g. PDA

Advantages and Disadvantages


there shouldn’t be
much of a need for
training, as most
people are already
familiar with the
concept


ICT systems can be
similar to manual
ones


no need for
specialised data
collection sheets


It can be slow to
enter data


Transcription

(data
entry) errors can
occur


Handwriting
recognition can be
unreliable

Methods that read data optically include:


Optical Mark Readers (OMR)


Optical Character Recognition (OCR)


Punched cards, paper tape and

Kimball tags


Barcodes

Optical Methods

Advantages and Disadvantages


Large amounts of data
can be read quickly


Data can be read
without human
intervention


Easy for staff to use
Kimball tags or
barcodes


no
specialist knowledge
needed


Specialist equipment
is needed to prepare
the data for entry


e.g. tags or forms


Only good for a
limited range of data


closed questions


Medium is often
paper


easily
damaged

(not including optical character recognition)

Text is scanned then converted into real,
editable text

Optical Character Recognition

Advantages and Disadvantages


No special data
-
preparation equipment
required


it just uses
text on ordinary
paper


Data is easily read by
humans as well as the
computer


Recognition is not
100% accurate


Converted documents
will need to be
checked


Dirty or damaged
documents are
difficult to read

Voice recognition can be used for:


Controlling devices (small vocabulary
systems)


Dictation (large vocabulary systems)


Small vocabulary systems are usually
more reliable and may not need training

Voice Recognition

Advantages and Disadvantages


No special data
-
preparation equipment
required


you just
say the data


Data is easily
understood by humans
as well as the
computer


Little training is
required


Recognition is not
100% accurate


Dictation systems
need to be trained


Not everything


e.g.
mathematical
formulae


are easy
to describe in words

Cards can contain data on:


Magnetic strips


e.g. bank
cards and train tickets


these contain little data and
are easily damaged


Chips (Smart Cards)


such
as the new “Chip and Pin”
credit cards and some
loyalty cards
.
These contain
more data and are harder to
copy/forge

Card Input

The characters are printed in magnetic ink
at the bottom of cheques:

Magnetic Ink Character
Recognition

Account details

Advantages and Disadvantages


Data is easily read by
humans as well as the
computer


Little training is
required


you just
feed the cheques into
the machine


It’s difficult for
forgers to change
details


Specialist high
-
quality printing
equipment is
required


this
obviously costs more!

Encoding Information


Sometimes you might want to turn
information into data


i.e. to store it


this is called
encoding


Your data capture methods will form
part of the encoding process


how are
you going to collect the information?


How do you code information to make it
easy to re
-
process, without losing it’s
meaning?

Encoding Example


Often surveys have questions like this:



A level ICT is brilliant!


Disagree strongly


Disagree


Neither agree nor disagree


Agree


Agree strongly


How would you collect the responses?


Would that be the most reliable
method?