Part 1 Lectures on Information Technology PDF

Information Technology (IT) plays an essential role in supporting the activities of organisations. The development in Information Technology has accelerated and thus pushed the growth of industries to a very high level. Information Technology (IT) or Information and Communication Technology (ICT) i...

Information Technology (IT) plays an essential role in supporting the activities of organisations. The development in Information Technology has accelerated and thus pushed the growth of industries to a very high level. Information Technology (IT) or Information and Communication Technology (ICT) is a set of tools that helps one to work with information and perform tasks related to information processing. This set of tools includes the computer and its accessories, multimedia applications that let one hear, see and read about various topics, and the internet that lets one find information all over the world and communicate with people everywhere in the world. It must be noted that Information Technology does not necessarily mean computers but the computer is one of the vital components of ICT. Information technology (IT), as defined by the Information Technology Association of America (ITAA), is "the study, design, development, implementation, support or management of computer-based information systems, particularly software applications and computer hardware." IT deals with the use of electronic computers and computer software to convert, store, protect, process, transmit, and securely retrieve information. Today, the term information technology has ballooned to encompass many aspects of computing and technology, and the term has become very recognisable. The information technology umbrella can be quite large, covering many fields. IT professionals perform a variety of duties that range from installing applications to designing complex computer networks and information databases. A few of the duties that IT professionals perform may include data management, networking, engineering, computer hardware, database and software design, as well as the management and administration of entire systems. Page 1 of 26 When computer and communications technologies are combined, the result is information technology, or "infotech". Information Technology (IT) is a general term that describes any technology that helps to produce, manipulate, store, communicate, and/or disseminate information. Presumably, when speaking of Information Technology (IT) as a whole, it is noted that the use of computers and information are associated. The term Information Technology (IT) was coined by Jim Domsic of Michigan in November 1981. Domsic created the term to modernise the outdated phrase "data processing". Domsic at the time worked as a computer manager for an automotive related industry. Information and Communications Technology - or technologies (ICT) is an umbrella term that includes all technologies for the manipulation and communication of information. The term is sometimes used in preference to Information Technology (IT), particularly in two communities: education and government. In the common usage it is often assumed that ICT is synonymous with IT; ICT in fact encompasses any medium to record information (magnetic disk/tape, optical disks (CD/DVD), flash memory etc. and arguably also paper records); technology for broadcasting information - radio, television; and technology for communicating through voice and sound or images - microphone, camera, loudspeaker, telephone to cellular phones. It includes the wide variety of computing hardware (PCs, servers, mainframes, networked storage), the rapidly developing personal hardware market comprising mobile phones, personal devices, MP3 players, and much more; the full gamut of application software from the smallest home-developed spreadsheet to the largest enterprise packages and online software services; and the hardware and software needed to operate networks for transmission of information, again ranging from a home network to the largest global private networks operated by major commercial enterprises and, of course, the Internet. Thus, "ICT" makes it more explicit that Page 2 of 26 technologies such as broadcasting and wireless mobile telecommunications are included. WHAT IS A COMPUTER? 1. A Computer is an electronic device capable of accepting a logical sequence of instructions and data, stores them, performs logical and arithmetic operations and in turn supplies the user with results of these processes. The computer may therefore be thought of as being made up of two parts, namely the Hardware (that is the electronic) or the physical part, and the Software the logical sequence of Instructions or programs. Computers follow explicit directions or instructions from both the user and the programmer. 2. It can also be said to be a set of interacting components responding to inputs to produce output. The major purpose of the computer is to speed up problem solving and increase productivity. It is clear from the definitions of computer that the machine can perform four basic functions; that is, accepting, storing, processing and giving outputs. CLASSIFICATION OF COMPUTERS Computers can be classified according to the following:- By type, By purpose and By capacity. 1. BY TYPE:- There are basically two types of computers namely. Digital and Analogue. There is however a third type called hybrid. DIGITAL COMPUTERS: A computer is described as digital if it handles information in discrete form. Digital computers are binary, they use electrical devices which operates in two state i.e. zero (0) and one (1) or on and off. Page 3 of 26 ANALOGUE COMPUTERS: Analogue Computers handle data/information presented to it in a continuous form. They are associated with measuring instruments such as thermometer, voltmeter, speedometer in which the information varies continuously like the pointer of a dial. They are slower than digital computers. HYBRID COMPUTERS: Hybrid Computers combine the facilities of both digital and analogue computers 2. BY PURPOSE Computers can also be classified according to the purpose or application to which it is put. We have Special purpose and General purpose Computers. SPECIAL PURPOSE COMPUTERS: A Computer is said to be special purpose if it is designed to solve a specific class of problem for which it was made. An Example is a computer which is used to control a chemical processes, computers in digital watches and also those in machines used by a cashier to enter sales GENERAL PURPOSE COMPUTERS: A General-purpose computer is not limited to the number of applications it can be used for. Under general-purpose computers, one can describe a computer as being scientific if it solves problems involving large amount of calculations but generally produces few lines of results; such a computer is referred to as calculation bound. A General Purpose Computer may also be described as commercial if it solves problems involving little calculations but large volumes of outputs are produced. Commercial computers are therefore referred to as input/output bound. Page 4 of 26 BY CAPACITY The capacity of a computer refers to the volume of data or information it can process or store and the speed at which it works. Computers can also be classified according to capacity. These are Micro (small) Computers, Mini (medium) Computers and Macro (large) Computers. These classifications are based on the memory size but not the physical sizes. MACRO COMPUTERS; Also called Mainframe Computers are very large computers in terms of price, memory size, power and speed of processor. The dominant manufacturer of macro computers is IBM. Others include; Burroughs, Univac, NCR. They have the following characteristics; i. Very expensive ii. They have a wider variety of peripheral devices that are not found with the small computers. iii. They generate a lot of heat iv. Support more users than most of the small computers v. They have a very large memory. Many organisations do not need mainframe computers for their data processing because they will be too big and expensive to justify the volume of processing that will be needed. The largest mainframe computers are called Super Computers. It is used to handle gigantic amount of scientific calculation. It is maintained in special rooms or environment, very expensive and its speed may be about fifty thousand (50,000) times faster than a microcomputer. Super computers are used in the areas of defence and weaponry, weather forecasting, scientific research and space administration. This type of computer can have thousands of processors working together. Page 5 of 26 MINI (MEDIUM) COMPUTERS: A computer is one whose size, speed and capacity lies between those of the mainframe and microcomputers. They generally operate at faster rates and can store larger quantities of information than microcomputers. The most popular ones were made by DEC, which is now part of Compaq. MICROCOMPUTERS (SMALL COMPUTERS): Microcomputers are the smallest of all the computers. They are also called PC or desktop computers because they are used by one person at a time and are small enough to fit onto a desktop. The smallest general-purpose microcomputers are often called LAP TOPS because they are small enough to fit into a suitcase or are often used on one’s lap. They are commonly needed by Engineers to produce engineering drawings and to assist in the development of new products or used as file severs in networks. PARTS OF A COMPUTER Basically the computer is made up of two parts; namely, Hardware and software HARDWARE The hardware is the tangible or physical components of the machine, which you can see or touch or feel. The hardware is what sits on your desk and executes the software instructions. The computer Hardware is made up of the following; 1. Input devices, 2. Output devices, 3. System Unit 1. INPUT DEVICES-"How to tell the computer what to do" These are used to input, transfer or feed data or instructions into the computer in a form that the computer understands. The commonly used or standard ways to interact with the computer are – the Keyboard and the Mouse. Others are scanner, microphone and joystick. Page 6 of 26 A keyboard and mouse are the standard way to interact with the computer - Keyboard: It is the basic input device of the computer, which is most generally used by users. Data and instructions are entered into the computer by pressing the desired keys on the keyboard. The computer keyboard consists of; typewriter keys, cursor-movement keys, numeric keys, function keys and special-purpose keys. The standard typewriter keys have the same familiar Qwerty arrangement of letters, numbers and punctuation Mouse It is used to input data and instructions into the computer by pointing or selecting an icon or menu item and click. Page 7 of 26 Scanners: Scanners work as a photocopier machine. It is used to make copies of photograph, graphics and maps into the computer in a form that can be stored and manipulated. Scanners "digitize" printed material (like photos and graphics) and save it to a graphic file format (like.GIF or.JPG) for display on the computer. Joystick: This is a small lever that can be moved in any direction to move an object on the screen. They are mostly used in playing video games. 2. OUTPUT DEVICES: "How the computer shows you what it is doing" Output devices are used to display information processed by the computer into a form that humans understand and can use. This is how the computer sends information back to you. The most common output devices are: - Monitor (‘screen’): - The Monitor, also called Visual Display Unit (VDU) works like an ordinary TV Screen and it is the basic output device of the computer. A Monitor is said to monitor the activities or operations of the machine. A Monitor is either a Monochrome, which displays text graphics in a single colour, or a colour monitor, which displays text and graphics in various colours. Output display by monitors is called Soft copy. Monitors are of two types; that is, the Cathode Ray Tube (CRT) and Liquid Crystal Display (LCD). The CRT type has a pointed bottom and emits a lot of heat when is in operation. The LCD type is flat and it emits less heat. Page 8 of 26 Printers: Printers are used to print copies of information processed by the computer with differing quality of output. They are measured in dpi (dots per inch) and ppm (pages per minute), the higher the better. In other words it converts computer output into printed images. Output produced by the printer is called a Hard Copy. Printers can be grouped as impact and non-impact printers. Impact Printers With this type of printer, the head of the printer has direct contact with the paper when printing. It works the same way as a typical typewriter where on pressing a key, a bar hits the paper against an inked ribbon to get the character appear on the paper. An example of an impact printer is the Dot matrix. Dot-matrix Printer: It prints by forming images or letter and numbers out of dots, and using pins to strike an inked ribbon against paper. Popular manufacturers are Epson and Olivetti Non-Impact Printers With this type of printer there is no direct contact between the head and the paper. Examples of non-impact printers are; 1. Laser Printer:- Uses a laser beam source to create a shot-like image on a drum. These images are then changed with magnetically charged ink-like toner and transferred from drum to paper. Its action is like an office photocopier. Laser printers produce quality images than dot-matrix printers. HP and Canon produce most of these printers Page 9 of 26  2. Ink-jet printers:- Print by spraying one or more colours of small droplets of ink at high speed onto paper. It prints by squirting ink onto paper. Most ink-jet printers can print colour. They mix together the three primary colours (red, yellow and blue) to form all the colours of the rainbow. The ink comes mostly in a dual cartridge, one being black and the other colour. The popular manufacturers are HP and Epson Speakers: – They are used to transmit sound output from the computer. Plotter:- This is used to sketch or draw maps, graphs, plans etc. 3. SYSTEM UNIT The system unit is also known as the system cabinet. It is a rectangular shaped box, representing the central part of the computer, at a glance. It houses the power supply, disk drives, and the motherboard: 1. POWER SUPPLY This where power enters the computer and in turn distributes it to other parts that may need power. 2. DISK DRIVES OR SECONDARY STORAGE OR AUXILIARY STORAGE DEVICES These consist of devices that store data and programs on disk or tape. The media on which data is stored are known as storage media. In other words disk drives help to store instructions and data/information for future use. They are made up of floppy disk drive, hard disk drive and compact disk drive. Page 10 of 26 a. FLOPPY DISK DRIVE – Floppy disk drive contains floppy disk or diskette, which is used to store information. (With time, this storage device has become outmoded) It is a disk made of plastic and coated with magnetic substance, capable of storing data Floppy disk drives are usually labelled drive A and B. There are two (2) basic types of Floppy disks namely 3½ inches (small) and 5¼ inches (large). The 5¼ inches Floppy disks are outmoded and no computers are manufactured with their drives anymore. Diskettes are handy and can be used to transfer information from one computer to another. When the 3½ floppy disk is inserted into the drive it spins at a rate of 6-10 times per second. b. HARD DISK OR NON-REMOVABLE DISK DRIVE This stores data and programs onto hard disks that are not removable. The device and the storage medium are built together as a unit and cannot be separated. Hard disk drives are an internal, higher capacity drive which also stores the operating system which runs when you power on the computer This is usually called drive C. c. OPTICAL DISK OR CD-ROM This is used to hold or store text, graphics, movies and sound. It can only be read by a CD-ROM drive, but cannot generally be altered. It is thus a perpetual storage device. Its drive is labelled D. A CD-ROM drive is a high capacity storage device, which lets you, read data from the disk, but not write data back. The CD-Writer (Compact Disc Writer) This is used to write data or information onto a compact disk Page 11 of 26 USB FLASH DISK (PEN DRIVE) The USB (Universal Serial Bus) Flash Disk works as a friendly, secure, and lightweight removable mass storage device disk. It is plugged through the USB port and computers immediately detect and configure the disk without needing to restart the computer. One can read, write, copy and delete files just the same way as we use a hard drive. You can even play MP3 files, run applications or play videos directly from the USB Flash Disk. This USB Flash Disk is so light and compact that you can carry it with you anywhere. It comes in various storage capacities. It is also just the size of a cigarette lighter, pen, or key chain, and because it uses durable solid-state storage flash memory, there are no moving parts inside making it shock resistant and longer to use. 3. MOTHERBOARD The motherboard or system board is the main circuit board in the system unit. It consists of flat board that fills the bottom of the system unit. The board contains the “brain’ of the computer (the CPU or microprocessor) the main memory or electronic memory and some sockets, called expansion slots where circuit boards or cards are plugged in. 1. MAIN MEMORY OR PRIMARY STORAGE (Electronic Memory) This is where data and instructions are temporarily stored for manipulation and execution. Primary storage may be divided into two (2) parts, namely ROM and RAM.  ROM – Read Only Memory This forms a small proportion of the main memory. It stores vital data and programs such as those needed to boot the computer when it is put on & which Page 12 of 26 needs to be in memory at all times. Data and programs in this area cannot be altered; hence they are said to be non volatile.  RAM – Random Access Memory This forms a major proportion of main storage. Data and instructions in this area can be altered. The size of the primary storage determines the amount of data that can be processed at a time and how big and complex a program may be used to process it. Primary storage is said to be volatile, because it looses everything when power goes off. When you use a program, the computer loads a portion of the program from the hard disk to the much faster memory (RAM). When you "save" your work the data gets written back to the hard disk. 2. CENTRAL PROCESSING UNIT (CPU) This is the central part of the computer where data manipulation and execution of instructions take place. It is the brain of the computer and is made up of three parts, namely: a. ARITHMETIC AND LOGICAL UNIT (ALU) This is where all arithmetic operations (eg. Addition, subtraction, multiplication, division etc) and logical decisions (yes, no, true, false etc) take place. b. INSTRUCTION CONTROL UNIT (ICU) This fetches instructions from the memory into the Arithmetic and logical unit for execution. c. CLOCK This synchronises the activities of the ICU and ALU. At a tick of the clock, the ICU fetches one instruction from the memory into the ALU for necessary action. After that, the clock ticks again, for the next instruction to be fetched from memory by the ICU, into the ALU for execution. This process Page 13 of 26 is continuous until all instructions are executed. This process is known as the fetching execute-cycle. SOFTWARE It is a set of logically coded instructions or a program designed to be used by a computer to meet a user’s requirements. Software is normally provided by manufacturers or software developers. The Computer is a device that has no intelligence of its own, so it needs instructions or software for it to work. The software can thus be said to be a series of very simple computer instructions carefully organized to complete complex tasks. TYPES OF SOFTWARE Software can be classified as Operating system or Systems software and Application software. OPERATING SYSTEM or SYSTEM SOFTWARE These are programs designed to allow the computer to manage its own resources, hence we say that operating system or system software is the resource manager for managing resources like memory, input/output devices, processors and information within the computer system. An Operating System can also be said to be a set of instructions that explains to the CPU how to handle the keyboard, the monitor, the printer and the disk drives. Examples of operating systems are Disk Operating System (abbreviated DOS) Windows, Operating System 2 (OPS 2) and Unified Information and Computing System (Unix). Page 14 of 26 APPLICATION SOFTWARE Examples of application packages include; 1. Spreadsheet: It is an electronic equivalent of a chequered sheet. Examples of spreadsheet packages are; Lotus – 123, Quattro Pro, Microsoft Excel, 2. Word processing: A Word Processor enables computers to be used as a typewriter. Examples of Word processing packages are; Word Perfect, Professional Write, Microsoft word, WordStar 3. Graphics: This is used to draw or create images. Examples of Graphics programs are; Corel Draw, Harvard, MS chart, MS PowerPoint. 4. Desktop Publishing: It combines graphics with text, to create posters, newsletters. An example is Adobe Page maker. MS Publisher 5. Databases: A database program helps you manipulate long lists of data such as names, addresses, phone numbers etc about friends, customers, employees, students or any data. Examples are MS Access, DBASE, FoxPro, Oracle 6. Internet Browsers (Netscape Navigator, MS Internet Explorer, Mozilla Firefox) DATA REPRESENTATION BINARY CODE: When writing reports we have quite a collection of symbols to choose from, that is Letters A-Z, both lower and upper cases, numbers 0 – 9, and numerous punctuations and other special symbols such as, ?, $, % etc. etc. Human beings understand what these characters mean, but Computers do not understand them. Computers deal with these characters by converting them into the simplest form that can be processed magnetically or electronically. This is Page 15 of 26 called Binary form. Binary is used to refer to two distinct states, ON or OFF, YES or NO, PRESENT or ABSENT, ONE (1) or ZERO (0). A scheme of encoding data using a series of binary digits is called BINARY CODE Some common types are American Standard Code for Information Interchange (ASCII), Binary Coded Decimal (BCD) and Extended BCD Interchange (EBCDIC) Some common types are the American Standard Code for Information Interchange (ASCII), Binary Coded Decimal (BCD) and Extended Binary Coded Decimal Interchange (EBCDIC). For instance in ASCII coding, each character is made up of a combination of 8 bits A (01000001) a (01100001) B (01000010) b (01100010) C (01000011) 0 (00110000) 1 (00110001) 2 (00110010) 3 (00110011) = (00111101) ? (00111111) space (00100000) BINARY DIGIT (BIT) It is the smallest data or digit or impulse in a Computer. BYTE A Byte is a group of contiguous bits, usually eight (8) bits i.e. eight (8) bits is equal to a byte. Storage in the main memory is measured in bytes. A byte can be thought of as approximately equal to a character. Therefore, the letter A stored in the main memory (RAM) takes up one byte of space. The more memory you have in your computer the better. The main memory capacity in a computer can be increased or upgraded by buying more memory (composed of chips) and add. Page 16 of 26  COMPUTER VIRUSES A computer virus is a computer program (software or code) developed by ill-intentioned programmers, that, when downloaded or run, attach themselves to other programs and files and cause them to malfunction. Like biological agents, computer viruses live to replicate. Sometimes viruses are programmed to lie dormant for a while before they become active; thus, they can spread from disk to disk and system to system before they may be detected. HOW COMPUTER VIRUSES SPREAD Computer viruses become active when you run an infected program or start your computer from an infected disk. Once active, the virus spreads by attaching itself to other programs or files. WHAT DOES A COMPUTER VIRUS DO? A computer virus is a program whose purpose is to damage data by corrupting programs, deleting files, reformatting hard disk, or even infecting executable files. Computer viruses do not infect or damage computer hardware, they only damage software. HOW DO I KNOW I HAVE A COMPUTER VIRUS? The following examples may be indications that a computer has been infected with a virus. Although these problems can be caused by a non-virus problem, they are the most reported symptoms of an infection. Page 17 of 26 1) Programs take longer to load than normal. 2) Computer's hard drive constantly runs out of free space. 3) The floppy disk drive or hard drive runs when you are not using it. 4) New files keep appearing on the system and you don't know where they came from. 5) Strange sounds or beeping noises come from the computer or keyboard. 6) Strange graphics are displayed on your computer monitor. 7) Files have strange names you don't recognize. 8) Unable to access the hard drive when booting from the floppy drive. 9) Program sizes keep changing. 10) Programs act erratically. HOW TO PREVENT YOUR COMPUTER FROM INFECTION To prevent your computer from infection, the following must be noted: - 1. Buy your software from the original developer or source. 2. Do not allow pen drives used in other computers to be used in your computer. If you will allow, the pen drives must be scanned before use. 3. Install current and powerful antivirus programs in your system or computer. Antivirus programs are designed to fight against or remove computer virus. Some antivirus programs are ESET NOD32 and Norton. COMPUTER NETWORK A computer network is the connection of two (2) or more Computers in order to allow users to share information and equipment. TYPES OF COMPUTER NETWORK Basically, there are three most common types of Network. Namely, private network, public network and International network. Page 18 of 26 A private Network is specifically designed to support the informational needs of a particular business organisation. A public Network on the other hand is a comprehensive information facility designed to provide subscribers (users who pay a fee) or a large geographical area. INTERNET This is used to describe a communication network specially designed to provide users with international voice and data communications facilities. In other words, Internet is inter connections of computers Globally. The majority of these networks use undersea cable or satellite communication or radio. LOCAL AREA NETWORK (LAN) LAN is a private Network that serves a company or part of company that is located on one floor or in a single building. Page 19 of 26 A typical Local Area Network Network Architecture or Topology The arrangement of the computers in a network can be distinguished into topologies namely star, bus and. Ring Star Network This is when a number of small computers or peripheral devices are linked to a central unit, which is the host. All communication has to pass through the host before going to the clients Page 20 of 26 Bus Network Here each node in the network handles its own communication controls hence there is no host computer. All communications travel along a common cable called a bus. As information passes along the bus, it is examined by each device to determine its usefulness for that particular node. Ring Network In this network, each node is connected to two other nodes forming a ring. Here information is passed round the ring until they reach the right destination. WIDE AREA NETWORK (WAN) It is a type of network that covers a very large geographical area, for example a whole region, country or even the whole world. Page 21 of 26 A wide Area Network MODEMS The word MODEM is a contraction of MOdulate and DEModulate. They are widely used data communication hardware for network Modems allow you to communicate with other computers using a phone line. They convert digital computer signals to analogue signals (modulate) for transmission over the telephone lines, then to receive these analogue signals and convert then back to digital signals (demodulate). Their speeds are measured in bits per second (14.4, 28.8 and 56 thousand bits per second are standards). Page 22 of 26  BASIC SYSTEM MANAGEMENT This deals with the safety, care and maintenance of the computer system, so as to prolong the working life of the computer as well as the user. The following are necessary in a computer environment; a) Room – should be spacious enough b) Support – computer should be placed on a firm, flat surface c) Dust – should be dust-free or kept to the minimum Curtains should be provided machine should be covered after use dust absorbers could be used diskettes should be kept in their jackets or files d. Temperature – temperature in computer rooms should be low. The computer should be kept cool and protected from overheating. Turn off the computer when its temperature gets greater than 33o C. air-conditioners are recommended fans can be used in well ventilated rooms e. Light – there should be enough light in the room to avoid straining of eyes. Screen filters can also be used to protect the eyes, avoid direct sunlight on machines f. Power Supply – Power should be stable. Stabilizers, Uninterruptible Power Supply (UPS) are Recommended. Do not overload power source g. Cables and Joints – make sure all cables are correctly and firmly connected. h. Cleaning – clean the outer part of the computer with a soft, moist cloth. Internal cleaning should be done by an expert. i. Security – make sure only authorised persons get access to the Computer room. Page 23 of 26  Provide good security locks Make back-up copies of all data/information Provide a password on computer Provide fire extinguishers in computer rooms. A computer user should take steps to avoid physical and mental health risks to increase productivity. The following precautions could be adopted to prevent such health problems from the use of computers. 1. Eye strains can be prevented by taking a 15 minutes break every hour or two 2. The position of your hardware should be adjustable. a. You chair should have good back support b. The monitor table should be adjustable c. The monitor should be tilt-and-swivel kind d. The monitor should be at eye level or slightly below eye level. 3. Your sitting position should be two feet or more from the computer screen and three feet from terminals or sockets. This will prevent electromagnetic field emissions Page 24 of 26 DATA AND INFORMATION Data are facts, events, transactions and so on which have been recorded. They are the input raw materials from which information is produced. Data are raw facts and figures in isolation. These isolated facts and figures convey meanings but generally are not useful by them. Data are of various types, among them are: - 1. Alphabetic type 2. Numeric type 3. Alphanumeric type Alphabetic types are data which consist of only the alphabets i.e. from A to Z Numeric types are data which consist only of numbers or integers and the combination of digits from 0 to9. Alphanumeric are those type of data which are constructed by the combination of characters/Alphabets and Numeric data types. Information is data that has been processed in such a way that is useful to the recipient. In fact, information is data that has been interpreted and understood by the recipient of the message. Information is knowledge and understanding that is usable by the recipient. It reduces uncertainty and has a surprise value. Classification of Information a) By Source: e.g. internal, external, primary, secondary, government etc. b) By Nature: e.g. quantitative, qualitative, formal, informal c) By Level: e.g. strategic, tactical, operational d) By Time: e.g. historical, present, future e) By Use: e.g. planning, controlling, decision making f) By Form: e.g. written, oral, visual, sensory g) By Occurrence: e.g. at planned interval, occasional, on demand h) By Type: e.g. detailed, summarised, and abstracted. Page 25 of 26 Functions Performed by Information a) The reduction of uncertainty b) As an aid to monitoring and control c) As a means of communication d) As a memory supplement e) As an aid to simplification by reducing uncertainty and enhancing understanding, problems and situations are simplified and become manageable. Characteristics of Good Information Good information is: a) Relevant for its purpose b) Sufficiently accurate for its purpose c) Complete enough for the problem d) From a source which the user has confidence e) Communicated to the right person f) Communicated in good time for its purpose g) That which contains the right level of detail h) Communicated by an appropriate channel of communication i) That which is understandable by the user. Page 26 of 26