Survey Methodology Flashcards
Why is questionnaire pretesting important?
- To reduce measurement error and increase validity
- An opportunity to cross-check typical assumptions researchers make when drafting a survey
Examples of assumptions we make when designing questionnaires (4)
- Questions asked are appropriate and relevant, and have answers
- Questions are posed so that respondents understand what is requested
- Respondents can retrieve any information requested from memory
- Respondents can communicate their information using the response options provided
Types of measurement errors
- Validity error
- Measurement error
- Processing error
Types of representation errors
- Coverage error
- Sampling error
- Non-response error
- Adjustment error
Validity error
When the measurement doesn’t properly capture the construct of interest
Frame error
Frame error typically results from the frame construction process. For example, some units may be omitted or duplicated an unknown number of times, or some ineligible units may be included on the frame, such as businesses that are not farms in a farm survey.
Non-response error
Nonresponse error occurs at both the survey unit and participant level when some people in the sample are not interviewed, or skip certain sections.
Example: Certain types of respondents refusing to participate in the study.
If there is a difference between respondents and non-respondents, or if the response rate is low, this becomes a big issue.
Measurement error
Occurs when respondents are not providing answers that they should, given researcher’s intentions.
Example: People will answer questions even when they don’t know the meaning the terms or question wording.
Sampling error
Occurs when only a subset of the population is included in a survey and sampled units differ from the full population.
Example: non-probability based sampling introduces potential biases because the sampling error cannot be estimated.
You end up uncertain about how representative your sample is of your population.
Processing error
processing error refers to errors that arise during the data processing stage, including errors in the editing of the data, data encoding, the assignment of survey weights, and tabulation of the survey data.
Coverage error
Coverage error results when there are differences between the target population and the sample frame.
Undercoverage may occur if not all voters are listed in the phone directory. Overcoverage could occur if some voters have more than one listed phone number. Bias could also occur if some phone numbers listed in the directory do not belong to registered voters
Sampling frame
Subset of population, taken from a sampling frame or source of people
Usually smaller than the population since there usually isn’t a list available of all population members. I.e., the difference between all Facebook users and those using the Facebook web interface.
Sample
People who you expose the survey to
Respondents
The people who answer your survey
Probability-based sampling techniques (examples)
Intercept surveys
List-based samples (e.g., email invitations)
Pre-recruited probability-based panels of Internet users