Transcript UNIT 3 - REVISION POWERPOINT - ALL TOPICS File

GCSE ICT - REVISION
Unit 3 Revision
All topics covered use this to aid your revision
1 Data & Validation
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Batch total = meaningful total to validate data entered
(e.g. Wage)
Hash total = meaningless total to validate data entered
(e.g. house number)
Encoding = “m” for “male”. Speed of data entry, less
storage space, etc.
Transcription = misreading data
Transposition = typo
Verification = double keying, visual, parity (files to
website)
2 Data Logging & Control
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Sensors – PIR, pressure, light, sound, heat,
Actuator – open windows, etc.
Accuracy of readings, short/long time intervals.
Export to spreadsheet – advantages = sort, charts,
calculations.
Control – burglar alarm, etc.
3 Web & Presentation
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Optimise images = compression. Reduce file size
and therefore quality. Quicker download speeds.
4 Web Software
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Linked to controlled assignment task. House style, audience,
home page, master page, hyperlinks, navigation bar, flash
banners (leaderboard or skyscraper), icons (basket), hosting
site online.
HTML = code to make websites.
Golden triangle = eye tracking study – keep content in this
area.
Opening pages = URL (www.bbc.co.uk), links, menus, search)
Interactive features = forms, games, quiz, google maps, photo
galleries
Hexadecimal = 6 digit code used for all colours using
combination of red, green and blue. Standardises colours on
web but difficult to remember.
5 Presentation Software (PowerPoint)
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Templates – quicker to create.
Hotspots = dividing one image with a number of
hyperlinks
Animation, transition.
Speaker notes = prompts for speaker
Narration – record over presentation
Video & sound = multimedia. More interesting,
larger file size.
6 Multimedia
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MIDI = Musical instrument digital interface. Music
keyboard linked to computer.
Embedded = added to your file. Increases the file
size but will always be part of your web site.
Linked = link to where multimedia is saved. Does not
increase file size but if file is deleted the link will no
longer work.
Uses = education, entertainment, business, etc.
Need fast processor, large memory as dealing with
large file sizes.
7 Digital Imaging
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Bitmap = large file size(individual pixels), pixelated when
resized as pixels are stretched.
Vector = smaller file (formulae used), maintains image quality
when resized as formulae is amended. Limited colours = more
suitable for clip art style graphics, NOT photographs.
Smaller file size = quicker to upload/download
JPEG = compressed image, reduces quality. Used on web.
GIF = fewer colours used = small file size, again used on web.
Tools to manipulate (alter) images. Link to controlled
assessment.
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Transparency, Brush settings, red eye removal, filter effects, transparency, layers,
etc.
8 Animation
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Stop motion = individual frames are taken and added in
sequence. Wallace & Gromit. Claymation.
Key Frame = flash banner. Uses tweening to fill gaps in
frames between key frames. FPS = Frames per Second.
Looping
Rotoscoping = Live action traced to provide graphic image.
Onion skinning = shows a number of frames at same time to
help animator complete the next frame.
Uses = films, education, web animations.
Persistence of Vision = remember image for 1/25 sec after
image is no longer there. Flip book = how animation works.
9 Sound & Music
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MP3 = compressed file size. MP3 players more portable.
Can download from web quickly.
WAV = larger file size
WMA = windows media audio, also compressed.
Sequencer = compose and edit music.
Notator = Music composition
Sound wave editor = audacity!! Add effects to audio. Crop,
fade, etc.
Download – must adhere to copyright law.
10 Networks (2 slides)
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LAN = Local Area Network (e.g. school network)
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WAN = Wide Area Network (Internet)
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Topologies = Bus, Ring and Star. (Be aware of diagrams, include
printer and server)
Intranet = internal, private network
Extranet = external network open to variety of users (e.g.
employees, customers.
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Router = allows networks to communicate (e.g. to Internet)
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Switches = connects different computers as part of network)
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Gateways = allows 2 different networks to communicate (translate)
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Bridge = Join 2 LAN to form a larger network
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Packet switching = how data travels on network (in packets)
10 Networks (2 slides)
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Advantages = share data/files, share hardware (e.g.
printers), internal email, quicker to update software.
Disadvantages = Viruses could spread more easily, easier to
hack, maintenance (network manager) = cost.
Point of Sale (check out)
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Scan bar code of product (bar code reader or type using keyboard or touch
screen)
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Product number is searched on database
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Price and description is returned (screen), stock number reduced automatically
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Total cost calculated, itemised receipt (printer)
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Payment via cash, debit/credit card, etc.
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When stock level gets too low (below set re-order level) warning is sent and
suppliers contacted.
11 HCI – Human Computer Interfaces
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GUI = Graphical User Interface, e.g. Windows. Uses WIMP (Windows,
Icons, Menus & Pointers. Also Office assistants, online tutorials, customise
desktop. Easier to use, requires more memory and storage space.
Command line = type in commands, less storage space but more difficult to
remember commands.
Menu = easy to use as looking through different menus.
Voice UI = Use microphone, aids people with disabilities, background noise,
accents can make if harder to understand words.
Touch = mobile phones, point of sale, etc. Easy to use. Standard keyboard
will be easier to use compared to screen for some users.
Biometrics = eye/finger print scan. Do not need to remember password,
can help to reduce crime. Expensive system, people do not want personal
details logged by computer.
12 Organisations
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There are a number of sub topics, view notes for more detail.
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Banks
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ATM = cashpoint, number of services available. Access 24/7 in variety of locations.
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MICR = Magnetic Ink Character Recognition. Used on cheques to display account number,
sort code (branch) and cheque number) – processes cheques quickly
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Real time processing - computer responds immediately to input (e.g. burglar alarm
responding to a sensor)
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Real time transaction processing – immediate response linked to transaction such as
withdrawing money, buying theatre tickets. Ensures that double booking is avoided and
financial record are updated as soon as possible for accurate figures.
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Batch processing – a number of items to input (e.g. cheques, gas meter readings, mobile
phone usage) and collected and then processed at a later time). This often happens at the
end of the working day or through the night to produce Mobile phone bills, etc.
12 Organisations
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Expert System
Uses Artificial Intelligence (AI).
Uses a database collated from a number of experts in a
particular field (e.g. doctors, car mechanics, etc.)
User can input details (e.g. symptoms)
The database will then be searched and the results displayed
on screen (e.g. what the diagnosis is, how to treat)
Uses a number of experts so wide pool of knowledge. Frees
up doctor time.
Some patients prefer more personal approach.
Time consuming and expensive to develop.
13 Social & Environmental
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Homeworking = working from home
Teleworking = working from home using internet. Work hours to suite
individual, less money & time linked to travel. Company saves on
overheads for office, electricity, etc.
Can be disturbed at home, could feel isolated (lack of social contact).
Company may find it more difficult to monitor staff. Security concerns for
sending data off site.
Employment patterns – some processes have changed = retraining and/or
redundancies. New jobs created = network managers, web developers,
systems analysts, etc.
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Greater collaboration
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Sat Nav = select route to reduce amount of fuel
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Heating = turn off at times to conserve energy
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Video conferencing = less travelling
14 Legislation
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Data Protection Act. 8 principles (rules) including
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Data must be accurate and up to date
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Data must be safe and secure
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Data must be processed legally
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Data must be used for specified purpose
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Data must only be kept for suitable length of time
Exemptions (Do not have to follow law)
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National security, Taxation, Police, Hospitals
Your rights (Data subject)
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To view data stored about you and correct if necessary.
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Computer Misuse Act Exemptions – Hackers(Fraud & Blackmail) & Viruses
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Investigatory Powers (Police can access email, voicemail, texts, listen to calls)
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Electronic Communications Act (encryption on internet is correct)
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Health & Safety at Work – to protect employees
15 Emerging Technologies
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Smart cards – encourages “cashless” systems. School canteen,
printing, bus. If card lost others could use.
QR codes – like a bar code but able to store more information
including hyperlinks. Often used in conjunction with smartphone
camera & apps.