INFO2 – Living in a Digital World

Revision

ICT System and Components

• What is ICT• The use of technology for the input, process, storage

and transfer of data• The output of information

• What is a system• Involves three main stages

• Input– Data is input

• Process– Calculations, queries and operations are performed

• Output– Results are sent to an output device

What is an ICT System?

• Where the output from the system goes directly to a human being or into another ICT system

• Why to use them– Meet particular organisational needs– Help fulfil goals– Produce information otherwise done with a paper-

based system– Situations where it is impossible without processing

speed of computer

Components of ICT Systems

• People– Client, users, audience– Sales

• Processing transactions of sales of goods/services– Finance

• Managing money flow– Operations

• Carrying out main business

• Data– Raw, unprocessed facts and figures

• Without processing have no meaning

Components of ICT Systems• Procedures

– Code of practice in work place• How they can use their ICT systems• Data Protection Act• Computer Misuse Act• Copyright, Designs and Patents Act

– Using usernames/passwords– Anti-virus software– External input devices

• Software– Increase the functionality of the system– Choice depends on needs of the users– Variety of types

• Bespoke• Off the shelf• Special purpose

Components of ICT Systems

• Hardware– Dependent on type of processing and output required– Storage and processing are main features– Sometimes includes specialist output devices– Main components

• Input devices• Processors

– CPU• Output devices• Ports and cables

– Parallel, serial, USB• Storage devices

• Information– Data which has been processed and given meaning

Data and Information

• Data– Raw, unprocessed facts and figures with no

meaning– Types

• Text• Numbers• Still/moving images• Bits and bytes

– Bit = single binary unit

• Information• Data processed into a meaningful/useful format

Coding and Encoding

• Encoding– Process of putting a sequence of characters into a

specialised format for efficient transmission or storage– Finding an alternative way to represent data

• Make it easier to port across various platforms

– Data for ICT systems needs to be encoded into machine understandable formats

• Pictures into vector graphics or bitmapped• Sound into wave• Text into documents• Movies into movie files• ASCII code (binary) is also used

Coding and Encoding• Coding

– Entering data into a computer can be a slow process and as data is entered errors can appear

– Data can take up large amounts of storage– Most ICT systems need data to be encoded so it is reduced in size,

saves computer space and reduces errors through misspelling– Often coded during collection or during input

• Coded takes less effort to type in• More data can appear on screen• Takes less storage space• Easier to check it is accurate using validation

– Example• Gender (M/F)• Sizes (L/M/S)• Airports (LHR/MAN)

Coding and Encoding

• Coding– Advantages

• Quicker to enter into computer• Requires less disk space to store• Less memory to process• Processing easier/possible as fewer responses• Improves consistency

– Spelling mistakes and human error less likely• Validation easier to apply

– Disadvantages• Information coarsened as forced into categories

– Might not be a category that matches what you want to record• The granularity needs to be chosen carefully to maintain

quality of information– Intervals or number of categories

Quality of Information• Accuracy

– Information must be accurate to be of value• Up-to-date

– Information can be worthless if not available when needed or out of a timescale

• Complete– Not complete = loss of value

• Reliable– Internet not always reliable, should be from trusted

source– Less likely to be true

• Relevant– Only valuable to someone who has a use for it

People and ICT Systems

• Design and purpose– System needs to be appropriate for user– Key factors

• Ensure implementation cost is worth benefits• Timescale for implementation

– Realistic and have time for testing

• Need to involve clients and end users– Ensure it meets requirements

• Needs and requirements of clients and end users

People and ICT Systems – Characteristics of Users

• Experience–Novices, beginners and experts

» Physical characteristics–Disabilities, impairments

» Environment of use–Quiet office = sound through headphones–Loud factory = visual display

» Task to be undertaken–Restaurant = concept keyboard

» Age–Older user = slow response/reaction

People and ICT Systems – User Interfaces

» GUI– Windows, Icons, Menus, Pointers– Intuitive and easy for inexperienced users

» Menu– Limited choice– “Drill down” to choice– Good for inexperienced users

» Command line interface– For experienced users– Text based commands to perform functions– Need to know correct commands to work

People and ICT Systems – Working in ICT

» Essential skills– Good written communication skills– Good oral communication skills– Problem-solving skills– Patience– Willing to work flexible hours– Teamwork

» Characteristics of an effective team– Strong team leader– Tasks allocated correctly– Appropriate structure so that standard practices are followed– Monitoring task progress– Costs are monitored– Checks that it produces what it’s meant to– Balance of skills and people that can work together well– All possess good communications skills

Transfer of Data in ICT Systems• Transferred through networks

– Networks = several different computing devices all connected together

– 3 main types• LAN

– Local Area Network– Small geographical area– Within a school or single business building or floor

• MAN– Metropolitan Area Network– Average geographical area/connecting a town or city– Buildings of the same business all connected together

• WAN– Wide Area Network– Large geographical area/worldwide– The Internet

Transfer of Data in ICT Systems• Advantages of a LAN

– Share storage, printers, scanners, etc.– Share data– Share software– Easy to upgrade/set-up new users as centralised– Ability to communicate with other users on network– Centrally controlled security (access and backup)– No need for duplication of data

• Disadvantages of a LAN– Central server fails = network users can’t work– If part goes down, some resources not available– Hackers have access to whole network if they gain access– Viruses spread easily– Increase traffic = decrease performance– Dependency on systems manager to provide service– Little local control over machine– Expensive due to purchase of other equipment– Reliant on other users not hogging resources

Transfer of Data in ICT Systems• Types of LAN server

– Peer-to-peer (P2P)• Two or more computers linked together (max 15)• Resources are shared among equals• Can be done wired or wirelessly• OS defines what resources are shared• All computers have similar rights• Doesn’t need a dedicated network operating system• Transfer data across network through Bluetooth• Many security risks so measures should be taken

– Client-server• In large organisations• Server based• Each client/workstation connected need client version of network

operating system• If server goes down, all users affected• Central storage and sharing of programs and data• Central backup

Transfer of Data in ICT Systems• Network topologies

– Star• Each node in star connected to central computer that controls

network• Signal travel from server to station along each individual

station’s cable• Polls each station to see of they have a signal to send

– Handles signals as received• Advantages

– 1 cable fails, others not affected– Consistent performance– No collisions of data as each station has own cable– Easy to add new stations without disrupting network

• Disadvantages– Costly to install due to length of cable– Reliance on central host

Transfer of Data in ICT Systems• Network topologies

– Bus• Networks share single cable• Information sent from any PC to any other PC• Some strategy needed for when multiple systems want to send data at one time• Advantages

– Easy and inexpensive to install» Needs less cable

– Easy to add more stations without disrupting network• Disadvantages

– Whole network goes down if cable fails at any point– Cable failure difficult to isolate– Network performance degrades under heavy load

– Ring• Series of computers connected, no central control unit• All computers can connect and interact with one another

– Messages specifically addressed to destination computer• Advantages

– No dependence on central computer» Each node controls transmission to and from itself

– Transmission around ring relatively simple» Messages travel in one direction only

– Very high transmission rate possible• Disadvantages

– 1 node breaks = transmission between any devices in ring is disrupted

Transfer of Data in ICT Systems• The Internet

– Collection of wires that connect all systems using it

– Physical components– The network of networks

• The World Wide Web– Way of accessing information over medium of

the Internet– Uses HTTP protocol– Collection of web pages stored on computers

around the world

Transfer of Data in ICT Systems• Standards

– De facto• No formal agreement in place• Particular standard has become one most commonly used in practice• Hardware, software, languages, protocols and formats that are widely used but

not endorsed by a standards organisation• Common place but not official

– De jure• Legally binding industry standards that manufacturers have to work to• Can slow down development but beneficial to manufacturers and end users

– Minimise compatibility issues• Often start as de facto and through acceptance and working correctly become

de jure• Protocols

– Transmission Control Protocol and Internet Protocol manage data flow over the internet

– Includes formatting rules for how data is packaged into messages– Many others exist

• HTTP• FTP• POP3• SSL

Safety and Security of Data in ICT Systems

• Threats– Hackers/crackers– Paedophiles– Identity theft/fraud– Viruses– Terrorists– Organised crime/hooliganism– Blackmailing/stalking– Natural disasters

• Internal threats– Hardware failure– Faulty procedures– Poorly trained staff– Use of laptops– Dishonest employees

• Protecting data– URL’s starting with https shows a secure website– Padlock logo in task bar shows reputable/secure site

• Transactions are encrypted

Safety and Security of Data in ICT Systems

• Malpractice and crime– Employee leaving password on a post-it on their

computer– Use USB with virus on it on workplace system– Going against companies code of conduct

• Protecting ICT systems– Physical restrictions

• Swipe cards, servers in locked room/box– Usernames and passwords– Access rights– Backup– Data scrambling using encryption– Training staff– Virus checkers/firewalls– Uninterrupted power supply

Safety and Security of Data in ICT Systems

• Legislation– Computer Misuse Act

• Deliberately planting a virus in a computer to cause damage• Using computers in work time to do unauthorised work• Copy computer programs illegally• Hack into someone else’s system to view/change information• Use computer to commit fraud

– Data Protection Act• See data held about them• Have errors corrected• Refuse data to be processed for direct mail• Refuse to allow sensitive data to be processed• Complain to data protection commissioner about any abuse of

the act• Claim compensation if damage caused due to misuse of act

Safety and Security of Data in ICT Systems

• Legislation– Copyright, Designs and Patents Act

•Covers wide range of data files– Music, literature, etc.

•Without owners permission, illegal to– Copy software– Install pirated software– Transmit software to create a copy– Use software without proper licence

Backup and Recovery• Types of backup

– Full backup• Copy of everything on the system is stored• Takes a long time• Only effective if its done whilst data is not in use

– Incremental• Backup only of elements that have changed since last full or incremental backup

– Differential• Backup only things which have changed since last full backup• Only two backups required

– Full and differential• Does not mean data will change twice as full backup will have most recent version

– Master and transaction• Batch of transactions has occurred, data before update and transaction will be stored• System can return to state it was in before backup started

– Live• Every transaction can be recorded immediately in 2 separate places

– Mirror server or cloud storage• Payment is never lost

– Snapshot• Instant record or picture of most volatile data may be taken at suitable periods

– MS Word saves every 5 minutes

Backup and Recovery• Storage locations

– Fireproof safe on same site• For restoring immediately

– Fireproof safe on local sister site– 3rd party provider who might collect on a daily basis– On a mirror server

• Computer running same programs and data elsewhere– In the cloud using 2nd party support to store it

• Storage media– Memory stick– CD RW– DVD RW– External hard drive– Tape drive

• Magnetic tape like DAT– Mirrored computer– Cloud storage

What ICT Can Provide• Fast, repetitive processing• Vast storage capability• The facility to search and combine data

in many different ways that would otherwise be impossible

• Improved presentation of information• Improved accessibility to information

and services• Improved security of data and

processes

What ICT Can Provide – Is The Use Always Appropriate

• Have limitations for what they can be used for

• Have limitations for the information they can produce

• Don’t always provide most appropriate solutions

• ICT systems improve way we process data, make life easier, make work more efficient•Can get it wrong•Main reasons are hardware, software and inability to transfer data properly

What ICT Can Provide – Is The Use Always Appropriate

• Computer can store large amounts of data• Don’t have space, computer may freeze or stop

working• Processing large amounts of data takes up

processing space and time• If computer can’t operate fast enough, processing

isn’t efficient• Computer crashing could lead to loss of work

• Badly written/untested software• Won’t work as intended to• Bugs could cause system to crash/have errors

What ICT Can Provide – Why ICT Systems Fail

• Bugs in software• Implementing system too quickly• Requirements of organisation not met• Insufficient testing• No end-user involvement• Cutting costs with employees• Insufficient hardware• New system is not compatible with the old system

What ICT Can Provide – Types of Processing

• Batch• Wage slips• Data gathered in batches over period of time• Processed together at the same time• Doesn’t need human interaction

• Can be done at night so doesn’t affect processing speeds• Interactive

• Using a wizard• Dialogue created between user and computer

• Transaction• Buying products online• Each transaction processed as received• Must be completed before another can start

• Real-time• Nuclear power plant• React fast enough to influence events outside of system• Generally uses sensors and operates all that time• Uses feedback where data processed in time to turn on device so that

environment is maintained

Factors Affecting and Consequences of the Use of ICT

• Use of ICT influenced by• Cultural• Legal• Economic• Environmental• Social• Ethical