Before analysis and interpretation, it is necessary to edit the date to detect possible errors and inaccuracies, so that accurate and impartial results may be obtained. Thus editing means the process of checking for the errors and omissions and making corrections, if necessary.

The task of editing is a highly specialized one and requires high level of skill and carefulness to attain the proper degree of accuracy. 

Editing of Primary Data : While editing primary data, the following points should be considered :- 

• Editing for consistency 
• Editing for completeness 
• Editing for accuracy 
• Editing for uniformity or homogeneity

Editing of Secondary Data : Since secondary data have already been obtained, it is highly desirable that a proper scrutiny of such data is made before they are used by the investigator. Bowley rightly points out that “secondary data should not be accepted at their face value”.

Hence before using secondary data, the investigators should consider the following aspects :-

• Whether the Data are Suitable for the Purpose of Investigation in View : Quite often secondary data do not satisfy immediate needs because they have been compiled for other purpose. The variation can be in units of measurement, variation in the date/period to which data is related etc.
• Whether the Data is Adequate for the Investigation : Adequacy of data is to be judged in the light of the requirements of the survey and the geographical area covered by the available data. For example if our object is to study ;the wage rates of the workers in sugar industry in India and the available data cover only the state of Rajasthan, it would not serve the purpose.
• Whether the Data are Reliable : The following points should be checked to find out the reliability of secondary data - 

(i) The collecting agency was unbiased. 

(ii) The enumerators are properly trained. 

(iii) A proper check on the accuracy of the field work. 

(iv) Was the editing, tabulating and analysis carefully and conscientiously done