COMPUTER SYSTEMS

COMPUTER SYSTEMS

Computer – Is an electronic device that accepts and processes data into information and under the control of instructions stored in its own memory and output or store the results for future use.
ii) Data – Data are raw, unprocessed and unorganized (unstructured) facts and figures that are relatively meaningless to the user. E.g. number of hours worked by an employee.
iii) Information – Is derived from data. This is data that is processed, organized/structured and presented in a given context so as to make it useful. e.g., multiplying the hours worked by the hourly rate to get each employee’s gross earning. Information is an important component in decision making.

USES OF INFORMATION
(a) Decision-making
When managers are ready to make choices (decisions) they need good, accurate and up-to-date information. If they act without relevant information it could lead to disaster, and failure.
(b) Monitoring and control
Businesses will compare actual performance against its predicted (budgeted) performance. Then they will act upon it.
iv) Information Communication Technology/Technologies (ICT)
ICT is an umbrella term that covers any software or hardware product that can store, retrieve, manipulate, transmit or receive information electronically in a digital form. Examples include personal computers, digital television, email, robots, radio, cellular phones and networking hardware. For our study, we are concerned with computer (hardware and software) and telecommunications technology (data, image, and voice networks).
v) Information System (IS)
An Information System (IS) is a combination of hardware, software, personnel, data and procedures that interact to support and improve day-to-day operations in an organization. These elements of an Information System are also known as the components of an Information System.

CHARACTERISTICS OF HIGH-QUALITY DATA
The Audit Commission has identified six key characteristics of good quality data.
a) Accuracy
Data should be sufficiently accurate for the intended use and should be captured only once, although it may have multiple uses. Data should be captured at the point of activity.
b) Validity
Data should be recorded and used in compliance with relevant requirements, including the correct application of any rules or definitions. This will ensure consistency between periods and with similar organizations, measuring what is intended to be measured.
c) Timeliness
Data should be captured as quickly as possible after the event or activity and must be available for the intended use within a reasonable time period. Data must be available quickly and frequently enough to support information needs and to influence service or management decisions.
d) Relevance
Data captured should be relevant to the purposes for which it is to be used. This will require a periodic review of requirements to reflect changing needs.
e) Completeness
Data requirements should be clearly specified based on the information needs of the organization and data collection processes matched to these requirements.
f) Uniqueness
In order to add value to an organization, information must be unique and distinctive.

BASIC ELEMENTS OF A COMPUTER
a. Input; It is necessary to present data in a way that provide easy conversation into its own electronic pulse-based form. This is achieved by keying in data using a keyboard that changes it into machine sensible form.
b. Storage; Data and instructions enter the main storage, and are held until needed to
be worked on.
c. Control; the processor controls the operation of the computer. It fetches instructions from main storage, interprets them and issues the necessary signals to the components making up the system.
d. Processing; Instructions are obeyed and the necessary arithmetic operations are carried out on the data.
e. Output; Results are taken from the main storage and fed on a output device. This may be a printer which changes information in a printed form called Hard copy.
Advantages of Using Computers
a) Computers are fast.eg in manipulating figures
b) Have large storage capacities
c) Occupies a small area in the office (working area).
d) Computers are always accurate.
e) Computers can work for a long time without getting tired or bored.
f) Computer storage to neat offices (paperless offices).
Disadvantages of using Computers
a) Computers are expensive to purchase
b) One must be trained so as to use computer
c) Leads to unemployment
d) Laziness in working out simple activities e.g. simple calculations.
e) Requires power to operate

FEATURES OF COMPUTERS
1. Speed-the speed of a computer can be specified in terms of the processing speed or the access time that is, the time taken to find particular information. This speed is measured in fractions of seconds.
2. Accuracy- a computer never makes errors however; error may occur and some modern computers have features for detecting and correcting such errors. Usually errors are committed by the users feeding data to the computer hence the saying GIGO (Garbage in Garbage out).
3. Storage- a computer is capable of storing large amounts of data and it can produce this data again and again on demand. A human brain can never do that.
4. Diligence- a computer never gets tired or bored if it has to do the same job again and again.
Even if it has to do a million calculations, it will do the last one with the same speed and accuracy as the first one.
5. Automation- once the instructions have been given, a computer can carry on its job automatically till it is complete.
6. Versatile- a computer is capable of performing a large number of different jobs depending on the instructions fed to it and the hardware characteristics.