Thursday, February 28, 2013

The Data Processing Cycle

The Data Processing Cycle

When data is collected and processed, whether by a computer or by other means, a set of operations is carried out on it. This set of operations is called a data processing sequence or a data processing cycle.

Computer Studies-10_03

Fig 2 The data processing cycle

Figure 2 is a very general diagram of a processing cycle. Data which is output may be used as input, perhaps at a later date, thus completing the cycle. (In the diagram OUTPUT is linked to DATA COLLECTION by a broken line to indicate that this only happens sometimes.) Some operations may occur at different points in the cycle, between or as part of the operations shown in Fig 2 .

STORAGE

Data may be held for various lengths of time on a suitable material (or medium).

Worked question

Give three examples of data being stored, each one being at a different stage of the data processing cycle.

1- As the last stage of data collection data may be keyed on to disc, where it is stored while awaiting input to a computer.

2- During the processing stage data may be stored in the immediate access store of a computer.

3- Output data may be printed on paper, which is also a storage medium.

CHECKING

Data often has to be checked to see that it has been copied accurately and/or to see that it is reasonable .