Types of Data

Primary Data:
The primary data are the hand information collected, compiled and published by organization for some purpose. They are most original data in character and have not undergoing any sort of statistical treatment.
Example: Population census reports are primary data because these collected, compiled and published by the population census organization.

Secondary Data:
The secondary data are the second hand information which are already collected by someone (organization) for some purpose and are available fr the present study. The secondary data are not pure in character and have undergone some treatment at least once.
Example: Economies survey of England is secondary data because these are collected by more than one organization like Bureau of statistics, Board of Revenue, the Banks etc...

Statistical Data:
A sequence of observation, made on a set of objects included in the sample drawn from population is known as statistical data.

(1) Ungrouped Data:
Data which have been arranged in a systematic order are called raw data or ungrouped data.

(2) Grouped Data:
Data presented in the form of frequency distribution is called grouped data.