Question

outline the major causes of error that are due to sampling and non sampling processess in the conduct of survey reserach.

Answer 1

Sampling Error

Sampling Error denotes a statistical error arising out of a certain sample selected being unrepresentative of the population of interest. In simple terms, it is an error which occurs when the sample selected does not contain the true characteristics, qualities or figures of the whole population.

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. Moreover, they can also arise out of defective sample design, faulty demarcation of units, wrong choice of statistic, substitution of sampling unit done by the enumerator for their convenience. Therefore, it is considered as the deviation between true mean value for the original sample and the population.

Non-Sampling Error

Non-Sampling Error is an umbrella term which comprises of all the errors, other than the sampling error. They arise due to a number of reasons, i.e. error in problem definition, questionnaire design, approach, coverage, information provided by respondents, data preparation, collection, tabulation, and analysis.

There are two types of non-sampling error:

• Response Error: Error arising due to inaccurate answers were given by respondents, or their answer is misinterpreted or recorded wrongly. It consists of researcher error, respondent error and interviewer error which are further classified as under.
  • Researcher Error
    • Surrogate Error
    • Sampling Error
    • Measurement Error
    • Data Analysis Error
    • Population Definition Error
  • Respondent Error
    • Inability Error
    • Unwillingness Error
  • Interviewer Error
    • Questioning Error
    • Recording Erro
    • Respondent Selection Error
    • Cheating Error
• Non-Response Error: Error arising due to some respondents who are a part of the sample do not respond.