Data Collection

Data CaptureThis is the first stage involved in getting data

into a computerVarious input devices are used when getting

data to the computerIt is the process by which the computer

acquires data from the user

Data CaptureThere are two main ways of inputting data

into a computer:

Manual data input Automatic data input/data capture

Manual data inputData is entered directly into the computerThis is done one transaction at a time by

handThe various input devices are used in order

to enter the dataThis data input method can be long and

tedious

Automatic data inputData is entered directly into the computer

from source documentsThis method is considered faster and more

efficient

Source documentsThese are pieces of material (documents) on

which data is first recorded before it is entered into the computer

Data is captured from the source and then transferred directly to the memory of the computer for processing

Source DocumentsExamples of sources documents are barcodes

Data InputData captured or entered manually must be

checked in order to cut down on errors made by users

Data captured or entered must be verified and validated before it is processed and placed in storage

Data VerificationIt is a process whereby the data is checked

for accuracy and inconsistencies after data entry is done

This is to ensure there was accurate transcription or copying of the data

Data VerificationIn order to verify data the user may be asked

to enter the same data twice.Data typed in the second time is compared

with the same data already entered to determine a correct match

If a difference in the two entries is found, the data is deemed as containing an error

Data VerificationExample: being asked to enter your

password twice

Data ValidationOnce data has been entered into the

computer by the user, it is checked to ensure it obeys the rules which apply to it

This process of checking is called data validation

Data validation is the process of ensuring that a program operates on clean, correct and useful data

Data ValidationExample:

(1) being asked to enter your birthday according to the format – mm.dd.yy

(2) Checks fields to ensure data in these fields corresponds, e.g., If Title = "Mr.", then Gender = "M".

Exercise1. How are source documents used in the

process of data capturing?2. What is the difference between data

verification and data validation? Why are these processes important for the proper functioning of computers?