Veterinary Epidemiology and Zoonosis

Census Vs sample survey and Cocepts of sampling

CENSUS Vs SAMPLE SURVEY AND CONCEPTS OF SAMPLING

Census Vs sample survey

• If all animals in a population are investigated, the survey is a census.
• Census is the only means of measuring exactly the distribution of a variable in a population. But it is very difficult and impossible to conduct. So sample survey is designed well then a reasonably accurate and acceptable estimate of a variable can be made by examining some of the animals in the relevant population i.e. a sample.

Concepts of sampling

• The validity of sampling theory is based on the assumption that an aggregate of units can be divided into representative subunits and that characteristics of the aggregate can be estimated from the subunits.