1. Total Error = Systematic Error + Random Sampling Error

2. Errors zSystematic error zResults from imperfections in research design or mistakes in research execution. zTwo sources – respondent error and administrative error.

3. Errors zRandom sampling error zPurely statistical problem involving sample size. zHas nothing to do with research quality.

4. Systematic Errors zRespondent Error – Error resulting from some respondent action or inaction.

5. Respondent Error zNonresponse 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.

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

7. Respondent Error zAcquiescence Bias - Respondents are agreeable rather than truthful

8. Respondent Error zAuspices Bias - Response bias caused by respondent being influenced by the sponsor of the study

9. Respondent Error zExtremity bias - Respondents provide extreme responses to all questions

10. Respondent Error zCarelessness - Respondents do not read or complete survey carefully

11. Administrative Error zData processing error- Involves incorrect data entry, coding, or programming.

12. Administrative Error zSample selection error – Unrepresentative sample due to error in sample design.

13. Administrative Error zUnconscious Interviewer error – Interviewer misrecords answers.

14. Administrative Error zInterviewer cheating – Interviewer falsifies questionnaires.