iCT

TOPIC 1: An ICT system and its components

What is ICT? (Information Communication Technology) - It concerns any device or system that allows the storage, retrieval, manipulation, transmission and receipt of digital information.- ICT covers hardware such as computers, scanners and digital cameras. - ICT covers software such as systems software, word-processors, databases and spreadsheets. - ICT covers all the communications technologies we use such as digital TV, digital radio, email, internet, mobile phones and GPS. What is a system?- In every day life it is a way of doing things. - All systems involve input, process and output. What is an ICT system?- A way of doing something using ICT. - Businesses need many different ICT systems including purchasing systems, accountancy systems, banking systems etc. What do all systems have in common? - They all involve input, processing and output: INPUT:   Involves capturing or entering the data by keyboard but more accurate and faster methods are bar coding, scanning etc.                 Input involves turning data into a form that can be processed by the computer. PROCESSING: Means performing actions on the input data. Would involve performing calculations, searching, sorting, arranging, presenting, converting etc.OUTPUT: The results or information produced when the data has been processed. The 6 components of an ICT system  People - needed to supply the data to the ICT system and to make judgements and decisions from the output supplied from the system.  Data - Raw material of any ICT system and this is processed by the system to provide information (output).  Procedures - Determine what needs to be done and when. It covers the passing of data/information between different people.  Hardware - Is the physical components that make up the ICT system. Hardware includes input devices (keyboards, mouse, scanner), storage (memory, printer, plotter), the processor and output devices (screen, printer, plotter). Also included are the communication devices needed to send data across networks.  Software - Computer programs which provided the step-by-step instructions to get job done.  Information - The results from processing data. Information is the output from an ICT system.  * REMEMBERING THE ABOVE: Pe DISH Pro* 

TOPIC 2: Data and information

What exactly is data? - Data can be numbers, words, images or sound. - Meaningless data because they lack relevance. Ways in which data can arise:- From the results of an experiment- From a transaction - From the output of a management information system- From a survey- From automatic measurement of environmental quantities Coding dataData is often coded during collection or when input into an ICT system. The reasons for this are: - Coded data takes less effort to type in- More data can appear on screen- Takes up less storage space - Easier to check that a code is accurate using validation checks Encoding data- Process of putting information/data into a specified format that allows effective transmission or storage by an ICT system. - ICT systems are able to process data in binary code, so any data has been converted to this format before processing. - Opposite of encoding is decoding where the coded information is changed back into its original form. Examples of encodingASCII encoding - characters on keyboard are changed into a series of  binary digits. Reasons for encoding:  To compress data - occupies less space on storage device and makes it faster to send to another computer over a network.  To enable a file produced in one software package to be read by someone who does not have that software package available on their computer.   Encoding image files - Meaning the image is represented in a certain way when it is stored.- The types of encoding used for images are GIF, TIFF, JPEG, WMF, Vector, Bitmapped. - The way an image is encoded depends on how it is produced (e.g. by digital camera, scanned in, produced by paint/software etc). Data representation - When a character is typed from keyboard it is converted to a binary code which consists of a series of 1's and 0's. Its then processed by computer. - On a network, these binary coded characters are transmitted along a wire until the character is received at the other end where it is decoded and converted back to the character again. - Most computers represent characters using ASCII code (American Standard Code for Information Interchange). Types of encoding for sound files - Sounds are not digital so requires the data to be encoded. - Sound is quite complex, so to reduce the storage needed for sound files, a technique called compression is used during encoding. - There are many formats for sound files:  WAV - Used with Windows for storing sounds. Files not highly compressed.  MIDI (Musical Instrument Digital Interface) - Used mainly to communicate between electronic keyboards, synthesisers and computers. Files are compressed and small.  MP3 - Format uses compression to reduce size considerably.  Shockwave Audio - used for very high quality sound with very small file size. Key words: * ASCII - a code for representing characters in binary * Binary Code - code made up from a series of binary digits - 0 or 1 * Encoding - Putting information/data into a specified format that allows effective transmission or storage by an ICT system. Normally involves digitising the information.* Transaction - A piece of business e.g order, purchase, return, delivery etc. 

Aspects of data

Differences and detailsThe difference between data and information- Data are the raw values put into, stored and processed by a data processing system and that information is produced together with a context that adds meaning. - Raw data is relative because data processing often occurs in stages so the 'processed data' from one stage can be the raw data for the next stage of processing. - Information informs you of something you did not already know or it is presented in a way that is meaningful and useful. Converting data is what ICT systems do.Information- Information is data which has been:  Processed Converted to give it meaning  Organised in some way Examples of processing  Sorting Making decisions Performing calculations Grouping Organising Quality of information is a measure of: -  Accuracy: credit card statements must have the correct rate of interest applied to the balance, otherwise customers will complain and the card company can be prosecuted. - How easy the information is to understand: A copy of personal information has been sent to a customer and this contains coded information which they do not understand. The company would waste time trying to explain the codes. - The relevance for a particular use: a group has asked their record company for a breakdown of their royalties for all months over the last 3 years and the record company only gave them the total royalties for each year. The group wanted to look at the seasonal variations in their royalties but the information given would not show this. - How up-to-date the information is to understand: Food is usually stamped so that after a certain date it would be best not to eat it. All reports and printouts from a computer should be date stamped so that the user knows how recent the information is. - Timeliness of information: If a business can identify from its ICT systems, users that are about to make a purchase or change something in their lives, then they will be at a huge competitive advantage. The importance of keeping data up-to-date- Requirement under the Data Protection Act 1998 for anyone who processes personal data to keep that information accurate and up-to-date. 

TOPIC 3: People and ICT systems 

People and ICT systems and characteristics of users 

Characteristics of users- Users are the people who use the systems designed by others on a day-to-day basis. - Users have differing requirements dependent upon their experience, physical characteristics, environment of use, task to be undertaken and age.Experience - When a new system is introduced most users will need to be to trained to use it. - In small organisations that may not be possible so user has to train themselves by using manuals, online tutorials and books. - Users all have different experience in using ICT and any ICT solution needs to take this into account. Physical Characteristics- People with special/particular needs need to use computers as do disabled people.    > Users with sensory impairment - the user may not be able to read letters on screen properly - use font size that is easy to read and is large enough to read.    > Users with physical disability - affects users mobility - can use voice-activated systems to put data into the computer. Environment of useICT systems may be used:  at home on the move (plains,trains,etc) at work.  The requirements of any ICT system must take this into account.Task to be undertaken - The task to be undertaken will determine the user requirements. - For example, if user is entering a lot of text then you would look at the possibility of entering the text without the user having to type it in such as making use of the microphone. - The user requirements for a website could be:  easy to navigate - to quickly find information they require regular updates - so they don't rely on wrong information use of the coronet font, font colour, font size, background etc. - to make text easy to read fast load times - don't waste time waiting for pages to load  Ways in which the accessibility of a website or other ICT system can be improved - Websites and other ICT systems are often designed to be used by the general public. This would include people of all ages, nationalities, in different situations, with a range of disabilities, with different educational backgrounds, and different ICT skills. - To make a website more accessible:  Use plain, simple language.  Explain difficult words/phrases.  Offer different languages. Allow a user to have the webpage read out aloud to them - ideal for people with sight impairment.  Allow a user to change the size of the text.  Allow a user to change the colour of the text/background  Provide users with online help. 

How users interact with ICT systemsThe need for effective dialogue between humans and machines - Users need to be able to issue information to the device to tell it what to do and the device needs to understand what to do or if their is a problem, what that problem is. - The standard interface for the human inputting data into the computer is via the keyboard with the computer giving its response on the screen. Appropriate interface design to provide effective communication for users - The interface must be designed to enable the user to communicate effectively with the device and to also enable the device to communicate with the user.- A graphical user interface (GUI) is the most popular human/computer interface used by software manufactures for systems and applications software. - With a GUI the mouse is used as the main input device. - A GUI consists of the following features:    > windows   > icons   > menus   > pointers   > desktop    > drag and drop    > taskbarsCommand-driven interfaces- The user has to remember and issue commands to the ICT system to get it to do something. - Sometimes commands are entered using the keyboard and sometimes they are entered using lists of commands. Natural language interfaces- Issuing instructions to the ICT system in the same way that we would issue instructions to another human.   KEYWORD :* Interface - the point where two objects meet. In ICT this is usually between a device such as a computer, device scanner etc, and a human. The need for the provision of appropriate help and support for the users of ICT systemsOn-line help - All software packages should have an online facility were users can get help supplied by the package, rather than having to look through manuals or user guides. On-line help for novice users- The software should recognise and anticipate the users' goals and offer assistance to make the task easier. Microsoft Office uses Wizards that help through some of the more complex tasks. This form of assistance allows the users to accomplish their tasks in a shorter period of time. Appropriate training- It is much more productive to train users properly on any new systems they have to use. There are a number of ways this can be done:   

On-line tutorials which guide them through the essential features of the system interactive multimedia training resources provided on CD-ROM or DVD Classroom face-to-face teaching/training Paper-based instructional guides Individual tuition on a one-to-one basis Existing user base- New workers are advised to ask someone at work for help using the software. 80% of IT problems are solved by non-IT staff. Help-desks- Most large organisations provide help-desks. These are usually manned by someone from the IT department. - Purpose is to give expert advice to users regarding any software and hardware problems they may have.- It is possible for staff on the help-desk to look at the users screen and offer them advice over the phone without actually leaving their desk. Working in ICT Jobs available to ICT professionals:  Project manager software developer web designer  IT trainer technician  help-desk operator Difference between technical skills and personal skills- Technical skills are those skills that are necessary in order to complete a specific job in ICT. For example, a software developer would need programming skills in a particular computer language in which the program is being written. Programming is a technical skill and not a personal skill. - Personal skills are those a person possesses and which are transferable to any job or task. Examples of personal skills include team worker, listening skills, creative, excellent communicator, good written skills, good at problem solving, flexible and able to work under pressure.Business project manager/business analyst Roles include:  interview business users to determine their requirements for the system apply the techniques of systems analysis to business problems be knowledgeable about the technical options for a particular business problem work with developers and other computer professionals in teams work within a budget to produce the best system to solve a business problem  Technical skills needed:  knowledge of formal techniques - to be able to apply all the techniques of systems analysis to solve business problems knowledge of the application of hardware/software - to be able to understand what is technically possible A good understanding of both business and ICT - so that they understand the business problem being solved and can use the best ICT solution  Project management skills - to coordinate the activities of everyone involved in project Personal skills needed:  Communication skills - to be able to talk to users about what they want from the system and to present ideas to management Written skills - to be able to produce clear reports to managers, software developers etc.  Ability to work in teams - to be able to brief ICT staff such as software developers, web designers etc.  Problem solving skills - to be logical in going about solving a business problem

Software developer/programmerRoles include: writing new programs to solve business problems as per the brief given by the business/systems analyst  altering existing programming code to get the programs to work differently debugging the testing programs to remove errors producing program documentation   Technical skills include:  Programming skills - need to be proficient in a programming language such as visual basic Testing skills - need to be able to thoroughly test programs to ensure they are bug free Personal skills include: Ability to work in teams - need to work with other programmers, business analysts working on same project Ability to work under pressure - programs are written to deadlines, so pressure is always on to complete tasks on time Problem solving skills - need to be able to solve problems by the writing of programming code Meticulous in attention to detail - small errors can cause programs to crash, so detail is extremely important  Web designer/administrator Roles include:  creating websites that are functional and look good using programming skills and graphic design skills to create webpages make changes to an existing website to cope with the changing demands of the website ensure that the website works with the back-office software such as order processing, payment and accounts packages  evaluating the effectiveness of the website using user comments  Technical skills include:  proficiency in web design packages - need to be able to create websites/webpages using web design packages like dreamweaver.  design skills understanding of networks - to be able to link the website to other systems such as stock control and accounts  Personal skills needed:  creative skills communications kills willingness to keep up-to-date  listening skills  Help-desk operatorRoles include:  helping users with their ICT problems answering user problems by telephone finding out whether a problem needs a visit by an engineer Technical skills needed include:  good knowledge of software/system being used or willingness to learn about them networking skills - so that network problems can be solved remotely  hardware skills  Personal skills include:  listening skills communication skills ability to work under pressure willingness to learn new skills ability to work as part of a team approachable  ICT trainerRoles include:  designing courses to help users  delivering coursers to users on software packages, procedures, new programs, etc keeping up-to-date with the latest developments in ICT  Technical skills include:  skills in the software being used trouble-shooting skills  business skills - in order to understand how the users are likely to use the ICT systems  Personal skills needed include:  Teaching skills  Technical knowledge communication skills willingness to keep skills up-to-date  Technician/network administrator Roles include:  installing hardware and software maintaining all the equipment including networks  ensuring that all programs and data on the server are safely backed up upgrading hardware and software archiving files repairing hardware and correcting software faults setting up user accounts with user IDs and passwords  checking that all security hardware/software is working properly and up-to-date  Personal skills needed include:  good technical knowledge  problem solving skills  Effective ICT teams - Each person in a team brings different types of expertise and experience to the project. Advantages of working in teams: the project manage can assign tasks to the team member with the most appropriate experience and skills to carry them out team members are able to bounce ideas off each other the project can be completed in a reasonable time frame teams are able to help and motivate each other if a member of the project team leaves, then there is always someone else with project knowledge to take over teams can produce work which is far superior to that produced individually. Disadvantages of working in teams: project teams are harder to manage some people are better working on their own and do not like to be dependent on others lots of meetings are needed to coordinate all activities team members are dependant on each other  if one team member does not complete their task on time, then it can affect other team members and cause their tasks to run late Leading an ICT teamIt is essential a team leader is chosen with these skills:  Leadership skills to ensure all team members have faith in the decisions being made and to make sure everyone in team works well Technical skills and knowledge about the area of business being developed Management skills to be able to assign takes to team members who are the most capable of carrying them out  Skills in using project management software - team leaders need to use software to manage the project to produce critical path analysis charts and Gantt charts Previous team leader experience to understand all the likely pitfalls and problems Skills in budge control to make sure that the project does not go over budget  Being able to work under pressure especially being able to deal with the unexpected  Presentation skills  Motivational skills  Skills of team members

problem solving skills

strong communication skills

ability to work in teams

be able to adhere to deadlines

TOPIC 4: Transfer of data in ICT systems

Basic elements of an ICT network: network components 

Basic elements of an ICT network: communication devices networking software data transfer media standards and procedures.  Communication devices - Are those pieces of hardware that are needed to turn stand-alone computers into networked computers. Network Interface card (NIC) - Before a computer can be connected to a network it will need to have a network interface card. - It is a card containing circuitry along with a socket. The socket allows the connection between the computer and the cabling. - Card is simply slotted into the motherboard of the computer. - A network interface card:  prepares data for sending over the network sends the data controls the flow of the data from the computer terminal to the transmission medium.  KEYWORDS: * Transmission medium - the material which forms the connection between the computers in network * Network - a group of computers that are able to communicate with each other * Networking software - this is systems software which allows computers connected together to function as a network Hub- It is a simple device which is used to join computers in a network so that they are able to share files and an Internet connection. Switches (network switches)- Used to join multiple computers together in a network, - Are able to inspect packets of data so that they are forwarded appropriately. Because a switch only sends a packet of data to the computer it is intended for, it reduces the amount of data on the network, speeding up the network. Routers- Hardware device that join several wired or wireless networks together. - Usually are a combination of hardware and software which often act as gateways so that home computer networks can be connected to the internet using a single connection. Networking softwareNetworks need software to tell the connected devices how to communicate with each other. Network operating systems software- Need to coordinate the activities of all the computers and other devices connected to the network.- Examples of network operating system software include: UNIX  Linux  Novelle Netware    Network management software - Some tasks the network management software would help with include:  Making sure that all computers have up-to-date software with the latest security patches, so that hacker cannot get into the network.  Keeping track of the software being run on each computer and checking that there are licences for all the software being used. Keeping all application software up-to-date.  Providing remote control facilities so that help-desk staff can sort a users computer problem out by seeing exactly what is on the users screen.  Check that bandwidth is being used correctly. Finding out if a user has installed non-licensed software without permission on a networked computer.  Checking the speed of the processor and the memory used for a particular computer on the network. This can be useful to identify computers that need upgrades.  Data transfer media- It is the material through which data travels from one computer to another in a network. - Main forms of data transfer media are: metal wires fibre optic cable wireless.  Metal wires- Offer a high transmission speed but they do need to be installed and this can be expensive. There are three different types of wire.Unshielded twisted pairThe main features are:  thin wires are twisted to help cancel out interference thin wires mean easier installation only suitable for small networks.   Shielded twisted pairThe main features are:  wires are twisted  wires have a copper braiding which projects the data signals from outside interference/corruption more expensive than unshielded twisted pair greater transmission speeds than unshielded twisted pair.  Non-metal cables- Light travels faster than electricity, so this is why in many networks pulses of light are used to carry data. Fibre optic cable - Data being passed is encoded as pulses of light through a very thin glass fibre. Bundles of fibres are used to carry the data to and from the network.Advantages speed - the data travels much faster  small size - a huge amount of data can travel through a very small cable lack of electrical interference - they do not suffer from interference like metal wires.   Disadvantagecost - the devices needed to connect up the cable and the cable itself are more expensive.No cables at allWith wireless communication, the data transfer medium is the air through which the radio waves travel. Wireless - Enable people to connect to the internet or to a LAN wirelessly. This means they can work anywhere they can get a radio signal for their network. - To set up a small Wi-Fi network you need:

a broadband connection to the internet

a router

Wi-Fi enabled computers

KEYWORDS: * Hot spot - a region where the internet can be accessed wirelessly* Wi-Fi - a trademark for the certification of products that meet certain standards for transmitting data over wireless networks How Wi-Fi works

The router is connected to the internet by a high-speed broadband connection

2. The router receives data from the internet

3. It transmits the data as a radio signal using an antenna

4. The computer's wireless adapter picks up the signal and turns the radio signal into data that the computer can understand.

Advantages of Wi-Fi:  allows inexpensive LANS to be set up without cables  allows people the freedom of working anywhere a signal can be received  ideal for networks in old listed buildings where cables would not be allowed to be installed  global set of standards - you can use wifi all over the world  Disadvantages of Wi-fi:  power consumption is high - which means laptops soon exhaust their rechargeable batteries  there may be health problems in using wi-fi there may be security problems even when encryption is used  home networks have a very limited range can get interference if wireless network signals start to overlap.  Network standards and procedures- For devices to communication with each other in a network certain standards need to be used. - Standards are important because without them, one device could be sending data to another device in a form that the other device does not understand. - It is necessary to adopt certain procedures and make sure that all users are aware of them.- Without proper procedures:  the security of the network may be compromised  the network may run slowly users may fall foul of legislation work may be lost actions may inconvenience or annoy other users  actions may cost the organisation time in terms of employee time needed to sort out problems. 

ICT networks for different geographical scales and uses - ICT networks can be divided into two types:  Local Area Networks (LANs) Wide Area Networks (WANs)  LANs- The main features of LANs are:  confined to single building or site - the hardware and communications equipment is contained in one building or site. ownership of the communications equipment - the organisation actually own all the communications equipment that links the terminals.  WANs - The main features of WANs are: Hardware is spread over a wide geographical area - devices are spread over a wide geographical are. The devices are spread over multiple buildings and sites.  Third party telecommunications equipment is used - hardware in a WAN is situated in many sites, which can be in different countries. Telephone, radio and satellite communications are needed, which are supplied by a third party.  Network topologies and typesNetwork topologies - A network topology shows how the computers are connected when wires are used and if wireless issued, it shows how the devices in the network communicate with each other. The ring topology - All the computers are arranged in a circle- Data sent by one computer passes around the ring until it reaches the correct computer Advantages:  easy to add extra devices each computer has the same access as the others so not one computer can 'hog' the network.  Disadvantages:  if there is a break in the connection, then whole network fails faults are difficult to locate impossible to keep the network running whilst equipment is added or removed because there is only one path for the data to follow.  The bus topology - All the devices connected to the network are contact to a common shared cable called the backbone. - Signals are passed in either direction along the backbone. Advantages:  cost effective because of the small amount of cable needed simple cable runs makes it easy to install easy to add extra devices to the network  Disadvantages:  if more than about 12 devices are connect to network, then performance of network is degraded if there is a break in the backbone cable, then the network cannot be used.  The star topology - Uses a central connection point to connect all the devices on the network together. The central connection point can be a hub, a switch or a router. Advantages:  faults tolerant - if one of the cables fails, then the other computers can still be used load tolerant - extra computers can be added without much loss in performance because all the computers have their own path to the hub easy to add extra computers - extra computers can be added without disturbing the network.  Disadvantages : higher cost - the large amount of cabling needed makes it a more expensive topology  dependance on the central hub/switch/router - if the device at the centre of the network fails, then the whole network will fail.  The mesh topology - Data sent using a mesh topology can take several different paths to its destination. Advantages:  Fault tolerant - as there are many paths data can take to get to its destination, if one of the path fails, there is always another path that can be taken.  easy to locate faults.  Disadvantages:  higher cost - lots of cables harder to maintain - lots of cables Peer-to-peer or client-server Networks can be divided into two main types:  peer-to-peer client-server.  Peer-to-peer networks- Networks where each computer has the same status and they are able to communicate with each other on an equal footing. - This means that every computer can access all the resources of any of the other computers on the network. - Used for home networks. - P2P has become popular with internet users for sharing files between users. Each user is able to connect to another users computer over the network so there is no central management. - P2P software systems such as Kazaa and Napsteer are one of the most popular software applications with users. Advantages:  cost saving - no server is needed no network manager is needed - all users take responsibility for the network  easy to set up - simplest of computer networks lower operating costs - less setup and maintenance costs peer responsibility - users decide what resources other users can use on their computer.  Disadvantages:  backups cannot be made centrally - places responsibility on all the users to back up their own data users need more IT knowledge - as they will be responsible for the files on their own computers poorer security - resources are shared, so users have to decide what resources of theirs other users on the network can use some computers may run slowly - those computers that have resources on them that all the users use will run very slowly.  Client-server networks - Preferred choice for large networks. - All the computers are not the same status.- A more powerful computer is used as the central computer, where all the files and programs are stored, and this computer is called a server. The other computers on the network are called clients. - As the sever is such an important part of a client-server network, a network manager is usually appointed to be in charge of it. Advantages:  security is better - because it is centralised and a person is given responsibility for it centralised data - data is all held on the file server which means that all users have access to the same set of data back ups are taken centrally - regular back ups are taken by network manager which means data is unlikely to get lost faster access to programs and files - servers are used which are powerful computers, so the whole network runs faster centralised administration - all the administration of the network is performed centrally so users do not have to worry about it. Disadvantages:  more expensive - servers are expensive need specialist knowledge - needs to have a person who understands the technicalities of a network in charge of the network  software is sophisticated and expensive  Characteristics of networks The differences between the Internet and the World Wide Web> Internet - a huge group of networks joined together. Each of these networks consists of lots of smaller networks. This means that the internet consists of hardware. > World Wide Web - means of accessing information contained on the internet. It is an information-sharing model that is built on top of the internet. Uses HTTP, which is one of the languages used over the internet to transmit information. The WWW makes use of browser software to access documents called webpages.

- The internet provides more services than accessing webpages. Using the internet you have email facilities, instant messaging, usenet news groups, P2P. All of these require different protocols to that required by the WWW. - The internet is therefore the actual network whereas the WWW is the accessing of webpages using the internet. Intranets- A private network that uses the same technology as that used by the internet for the sending of messages around the network. - Main use is to share organisational information and share resources. - Main feature is that only employees of the organisation are able to use it. - Can still access internet. Extranets - an external network that can be used by customers, suppliers and partners of an organisation as well as the organisation itself.- Extranets are not accessible by the general public and this is ensured by usernames/passwords. - The internet is used for the sending of data, so the following security measures have to be put in place:  gateways  firewalls encryption user authentication

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