Data Processing Cycle
The stages of data processing can be shown diagrammatically, in a chart called the data processing cycle. Remember that stages mean step-by-step. You must not jump to step 5 before mentioning step 1.
The following are the stages of data processing represented diagrammatically.
Data Gathering or Collection Stage: This is the stage of gathering the original data for entering and processing. Methods of handling the source document include verification (ascertaining that the data has been accurately entered)
For example, gathering together the number of subjects offered by a student. This is recorded on a subject sheet called a source document.
Data Collation or Preparation Stage: This involves transcribing or sorting the source document, arranging them alphabetically or numerically.
Data Input Stage: This is the introduction of the sorted or prepared data to the processor. This can be done by a computer operator.
Computer input devices include;
- Joy Stick.
- Light pen.
- Track Ball.
- Graphic Tablet.
- Character Reader (OCR)
- Bar Code Reader
- Optical Mark Reader (OMR)
Data Processing Stage: This is the step or stage where calculations or logical operations are done. This is the only function that produces a new set of data. Processing is done in a computer by the Central Processing Unit (CPU) It is known as the brain of the computer.
Data Storage Stage: Storage is meant for keeping data awaiting processing and processed data. Examples are students’ scores which may be kept in computer storage media like a flash, CD, Hard disk, floppy disk, etc.
Processed data are stored in the main memory. The main memory is also known as primary or internal memory. There are basically two types of primary memory:
a. RAM (Random Access Memory)
b. ROM (Read Only Memory)
Data Output Stage: This is the stage where documents are printed and reports are written. Such outputs can be the percentage average of each student’s performance in a test, or the position of each student in the class.
Examples of output devices include Monitor, Printer, Projector, Speaker, and Plotter. Output devices such as printers and monitors accept text and graphic output from a computer and transfer the information on paper and screen respectively.