Exam Prep Stratified Random SamplingPopulation is divided into two or more groupscalled strata, according to some criterion, such asgeographic location, grade level, age, or income,and subsamples are randomly selected from eachstrata.Elements within each Usually it is set at 2.5% or 5% - depending on the risk or loss involved in drawing wrong conclusions.

The main reason behind sampling error is that the sampler draws various sampling units from the same population but, the units may have individual variances. Sampling errors do not occur in a census, as the census values are based on the entire population. no data has been obtained at all from a selected unit) or partial non-response (i.e. Error components are commonly divided into two major categories: Sampling and non-sampling errors.

Duddek, Income Research Paper Series, Statistics Canada catalogue no. 75F0002-No.003, May 2007. Conversely, non-sampling error is a basket that covers all the errors other than the sampling error and so, it unavoidable by nature as it is not possible to completely remove it. Non-sampling errors are due to all other aspects of the survey EXCEPT the sampling. Reply ↓ Ssesanga Enock on 30 August, 2016 at 4:44 pm said: Can you please explain more about the types of non sampling errors other than examples Reply ↓ Mrunal gandhi

The most common measure for the sampling error is the variance of an estimate, or derivatives thereof. The design factor of a strategy is thus defined as the fraction between the variances of the two estimators. ISBN 0-19-920613-9 ^ Fritz Scheuren (2005). "What is a Margin of Error?", Chapter 10, in "What is a Survey?", American Statistical Association, Washington, D.C.