The term enquiry means search for information or knowledge statistical methods such as collection of data analysis etc., Whenever a statistical enquiry is conducted, it is necessary to collect numerical data.
It is necessary to collect numerical data. It is the first step in all statistical enquiry. The investigator who collects the data should consider the following before he proceeds to collect them.
1. purpose of enquiry
2. sources of data
3. methods of data collection
4. nature and type of enquiry
5. unit of collection
