After the data are collected and edited, the next step to be taken up by a statistician is the classification of the data. Classification means arrangement of data into various groups, or categories of homogeneous character. Unless this is done, the next step towards the analysis of data i.e. tabulation, cannot be taken up, and the whole work of collection will go in vain. Thus, classification of data is prerequisite for tabulation, and further analysis, and interpretation of the data. It must be remembered that without classification, a heap of data will look haphazard, and confusing, and no purposeful meaning can be brought out from them.
The term ‘classification’ has been defined in various ways by various authors, some of which are cited here as under:
- In the words of Sacrist, “Classification is the process of arranging data into sequences and groups according to their common characteristics, or separating them into different but related parts.”
- According to Connor, “Classification is the process of arranging things (either actually or nationally) in groups, or classes according to their resemblances and affinities which gives expression to the unity of attributes that may subsist amongst a diversity of individuals.”
Thus, classification is the process of arranging or rearranging the data into certain groups, or classes according to their resemblances or similarities on a certain point viz. age, religion, education, income, expenditure, or occupation etc.