Broadly speaking, there are four types of classification. They are:
(i) Geographical classification, (ii) Chronological classification,
(iii) Qualitative classification, and (iv) Quantitative classification.
These are described in detail as under:
Under this type of classification, the data are classified on the basis of area or place, and as such, this type of classification is also known as areal or spatial classification. The areas may be in terms of countries, states, districts, or zones according as the data are distributed. For countries, states, districts, or zones according as the data are distributed. For the purpose of ready reference and ranking, the different classes form under the classification should be arranged in order of their alphabets or size of the frequencies respectively. Generally, in case of reference tables, alphabetical arrangements are made while in case of summary tables, ranking arrangements are made.
However, this type of classification is suitable for those data which are distributed geographically relating to a phenomenon viz. population, mineral resources, production, sales, students of universities etc.
Under this type of classification, the data collected are classified on the basis of time of their occurrence. As such, the series obtained under this classification is purely known as a time series. This type of classification is suitable for chose data which take place in course of time viz. population, production, sales, results etc. The different classes obtained under this classification are arranged in order of the time which may begin either with the earliest, or the latest period.
Under this type of classification, the data obtained are classified on the basis of certain descriptive character or qualitative aspect of a phenomenon viz. sex, beauty, literacy, honesty, intelligence, religion, eye-sight etc.
As such, this sort of classification is also otherwise known as ‘descriptive classification’. Such type of classifications are usually dichotomous in nature in which the whole data are divided into two groups viz, a group with the absence of the attitude such as blind and not-blind, or deaf and not-deaf etc.
Under this type of classification, the collected data are classified on the basis of certain variable viz. mark, income, expenditure, profit, loss, height, weight, age, price, production etc. which is capable of quantitative is also otherwise known as ‘classification by variables’.