Total Error = Systematic Error + Random Sampling Error

Errors

Systematic error Results from imperfections in

research design or mistakes in research execution.

Two sources – respondent error and administrative error.

Errors

Random sampling error Purely statistical problem involving

sample size.Has nothing to do with research

quality.

Systematic Errors

Respondent Error – Error resulting from some respondent action or inaction.

Respondent Error

Nonresponse error – Statistical differences between a survey that includes only those who responded and a perfect survey that would also include those who failed to respond.

Respondent Error

Deliberate falsification – Respondent may wish to appear “better” than s/he really is.

Respondent Error

Acquiescence Bias - Respondents are agreeable rather than truthful

Respondent Error

Auspices Bias - Response bias caused by respondent being influenced by the sponsor of the study

Respondent Error

Extremity bias - Respondents provide extreme responses to all questions

Respondent Error

Carelessness - Respondents do not read or complete survey carefully

Administrative Error

Data processing error- Involves incorrect data entry, coding, or programming.

Administrative Error

Sample selection error – Unrepresentative sample due to error in sample design.

Administrative Error

Unconscious Interviewer error – Interviewer misrecords answers.

Administrative Error

Interviewer cheating – Interviewer falsifies questionnaires.