Chapter1. Principles of Data Processing

Chapter1. Principles of Data Processing

Data and Information

          Data are facts or raw material for information. Data are represented by numbers, characters and symbols. Information is data arranged in an order and they are useful to the people for their needs. That is, information is relevant knowledge produced as the output of data processing. There for all information consists of data.

          In another words data are set of isolated, unrelated and uninterrupted raw facts that have confusions in its meaning. Information is a set of organized, validated, corrected and collected data that are meaningful.

          Let us take example to differentiate between data and information. Look at the following: - “Kamal”, “65”, “Y” Kerala”, “M”. They do not convey any meaning except that they are few English words/alphabets, a number and the name of a state. But, suppose that the same data are arranged as given below, and then it would be information, i.e.

Name: Kamal

Age: 65

Married: Y

State: Kerala

Sex: M

Need for Information

          1.      Need for Knowledge.

          2.      Need for Decision Making.

          3.      Need for Government.

          4.      Need to Improve Efficiency and Productivity.

          5.      Need for Better Service.

Qualities of Information

1. Accuracy

          The information must be accurate. Accuracy is the ratio of correct information to the total amount of information produced over a period. If 1000 items of information are produced and 920 of these items give a correct report of actual situation, than accuracy is 0.92.

2. Timeliness

          Timeliness is important characteristic information. Information must be available at the right time. Even if information is highly accurate, it is less use if it arrived late.

3. Completeness

          Information provided must be complete, to be meaningful for its users. Completeness means a better integration of related facts. Incomplete information will not help to make decisions.

4. Conciseness

          There is a tendency to provide a large volume of information. This becomes difficult to understand and interpret. Conciseness means that information must be as brief as possible. Concise information is most summarized and has only relevant data and should point out areas of exception to normal and planned activities.

Data processing

It is the activity to convert data in to information. The three activities in data processing are capturing data (Input), manipulating data (Process) and outputting the result (Output). It is classified in to two, Manual Data Processing (MDP) and Electronic Data Processing (EDP).

Data Processing Activities

          Data processing consists of three basic activities: Capturing the input data, manipulating the data and managing the output results.

Capturing the input data

          Data must be recorded or captured in some form before they can be processed. Data is first recorded on source documents - paper forms designed to accept input data - or they may be captured by keyboards, automated teller machines or other direct input devices that accept input data in a paperless, machine-readable form.

Manipulating the data

          The available data is subject to one or more of the following operations.Classifying, Calculating, Sorting, Summarizing.

Managing the output results

It includes Sorting, retrieving, communicating and reproducing.

Manual Data Processing v/s Electronic Data Processing

          In manual data processing, the 3 activities are performed with conventional methods so that are very slow. People do calculations manually. This is time consuming. Data are recorded in paper where the accessibility of information is less. It is time consuming to search and get the desired information. The accuracy of information produced in manual data processing is also less. This is because humans commit more errors. When volume of data is stored increases, storage space increases proportionately. Data recorded on paper can be easily damaged also.

          Electronic Data processing involves use of computer to perform all data processing activities. Since computers are very fast, accurate and reliable, this has a lot of advantages over manual data processing. Computers can process extremely large volume of data can be stored in little storage space. Storage devices provide fast access to data. Information can be quickly retrieved. Computer storage media is less level to physical damage than conventional storage of data in paper.

Computer for Data Processing

          Computer can be defined as it is an electronic machine designed to accept and store input data then Process them and produces output as results under the direction of a stored program. For data processing input devices, central processing unit, output devices and memory devices are used for input, process, output and storage respectively.

Characteristics of Computers

(Advantages of Computers)

Speed

A computer can perform millions of operations in a second. It can do in a minute, as much work as man can do in a year. The time taken to execute an instruction is only a few nano seconds (1 nano sec = 10-9 sec)

Accuracy

A computer can perform arithmetic calculations with a very high degree of accuracy. But accuracy, we means less errors in the output and also the precision with which calculation are performed. Because of high degree of accuracy, computers can be used to solve scientific problems.

Diligence

Since computer is a machine it can operate for long hours unlike human beings it will not show any emotions or disobedience. Due to this, they are best suited for routine jobs. They do not become lazy or express feeling for repetitiveness.

Versatility

The computer is a very versatile tool. It can be used to perform many different kinds of processing tasks. It is a general purpose data processing machine. It can perform any task that could be accomplished by a series of logical steps.

Huge Memory

Computers have enormous memory capacity. Huge volume of data can be stored in its memory for processing.

Disadvantages (Lack) of Computer

Lack of IQ

They don’t have the power to make judgment of their own. If a computer is given with wrong instructions or invalid data, it cannot identify this. Hence if will produce erroneous results.

Lack of Decision Making Power

Computers cannot take decisions they own and they do not possess the intuition capability, which are the assets of human beings.

No Emotions

Machines do not have any emotions or feelings. Though the computer can solve problems logically, they do not express any feelings or emotions.