Following are the essential elements in an ideal classification :

• Clarity : There should be no uncertainty or ambiguity as to in which class or group the compiled data should be kept. 
• Stability : Stability is necessary to make data comparable and to make out meaningful comparison of the results. 
• Extensiveness : The different sections should be composed widely in such a manner that no item of the collected data should be left out. 
• Suitability : The composition of the class should be according to the purpose. 
• For example: to find out the economic condition of the persons or the saving trend, it would be appropriate to create classes on the basis of income. 
• Flexibility : The classification should be flexible enough to accommodate change, amendment and inclusion in various classes in accordance with new situations. 
• Homogeneity : Units of each class should be homogeneous. All the units (data-items) included in a class or group should be present according to the property on basis of which the classification was done.

Objectives of Classification :

• Simplification and conciseness : The main objective of classfication is to eliminate the complexity of the collected data and to lend them a concise from, so that the classified data can easily be understood. 
• Clarification of Similarity and Dissimilarity : By keeping data-items in homogeneous groups having similar properties, separately, the similarity and dissimilarity between them can be easily understood. 
• Helpful in comparsion : he comparative study of data-items becomes easy through classification. If the populations of cities or village are categorised in class of literate and illiterate, married and unmarried, employed and unemployed, then both cities/villages can easily be compared on the basis of these attributes. 
• Logical arrangement : Classification is a logical process. The data-items included in it are presented in a regular and well-ordered manner.
• For example – classifying population data-items in classes of age, gender, caste-creed, state, etc. is a logical activity. 
• Presentation of the basis of tabulation : Tabulation is impossible without classifying unarranged and raw data, and statistical analysis is also impractical without it. Hence, the process of classification presents a basis for tabulation.