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Malachy Smyth



AS Level ICT
Revision Notes




2011 ­ 12

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AS Level ICT

Contents
Data and Information.............................................................................................................................. 2
Hardware and Software Components .................................................................................................... 5
Network Communications .................................................................................................................... 14
Applications of ICT ................................................................................................................................ 21
Developing ICT Applications ................................................................................................................. 24




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AS Level ICT


Data and Information
Characteristics of Data, Information and Knowledge
Data ­ Data consists of raw facts and figures, it has no meaning until it is processed and turned into
something useful.

Information ­ Information is data which has been processed within a context to give it meaning.…

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AS Level ICT

Transcription Errors
There are two types of transcription errors, Omission Errors and Transposition Errors.
An Omission Error is when information is left out.
A Transposition Error is when the correct information is keyed in but in the wrong order.

Verification & Validation
Data Verification ­ performed by…

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AS Level ICT

The Importance of Adopting Standards
A standard is a set of rules agreed between parties. In IT the standards or protocols are used to
ensure effective communication and sharing of data. Some standards are agreed by users (known as
De Facto) and others are agreed by governing…

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AS Level ICT


Hardware and Software Components
Input Devices
Keyboard
The normal keyboard includes alphanumeric keys, a numeric keypad, function keys and control keys.
It is used with a pointing device (mouse). Errors can occur easily while typing, called `typos'.

Concept Keyboard
An overlay sheet is placed on top of…

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AS Level ICT

stored shapes. Each shape is then interpreted as a character, or rejected. Finally, a digitised
representation of the scanned document is saved as a text file.

Optical Mark Recognition (OMR)
OMR is used to read marks in present positions or boxes from a specially designed form. It…

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AS Level ICT

Thermal Printers
These work in a similar way by burning the image onto the paper rather than using ink. They do save
ink but they also need special paper that costs more.

Ink Jet Printers
Also known as bubble jet printers they work by heating up ink…

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AS Level ICT

Speech Synthesis Software
Speech synthesis software coverts text into speech this type of system contains a database of words
and their sounds that are retrieved when a word is spoken. Sometimes the word and has to be
broken up into syllables. Some systems try to add `stress'…

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AS Level ICT

DVD-RW
DVD-RW is now commonly used to store backups because they have larger storage than a CD-RW.

HD DVD
Offers increased capacity, up to 30GB however they aren't widely available and where withdrawn in
2008.

Blu-Ray
A Blu-ray system uses blue light instead of red to read…

Comments

TamaraAllan

Report

does not include all of the AS Specification for the WJEC ICT Course

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