PRC Research Design & Methodology 3 — Questions and Answers
Question 1: A researcher measures income using brackets ($0–$25k, $25k–$50k, etc.). What level of measurement is this?
- Nominal
- Ordinal (Correct answer)
- Interval
- Ratio
Correct answer: Ordinal
Income brackets are ordinal because they have a meaningful order but the intervals between categories are not necessarily equal.
Question 2: Which threat to internal validity occurs when participants behave differently because they know they are being observed?
- Maturation
- Instrumentation
- Hawthorne effect (Correct answer)
- Regression to the mean
Correct answer: Hawthorne effect
The Hawthorne effect refers to behavior change caused by participants' awareness of being studied.
Question 3: When a researcher selects only the most accessible participants, this is called:
- Stratified sampling
- Convenience sampling (Correct answer)
- Purposive sampling
- Snowball sampling
Correct answer: Convenience sampling
Convenience sampling selects participants based on ease of access, which can limit generalizability.
Question 4: Discriminant validity is demonstrated by showing that a measure:
- Correlates highly with theoretically similar measures
- Does not correlate strongly with measures of unrelated constructs (Correct answer)
- Predicts outcomes better than competing measures
- Produces stable scores across test administrations
Correct answer: Does not correlate strongly with measures of unrelated constructs
Discriminant validity confirms that a measure is distinct from measures of theoretically different constructs.
Question 5: In survey research, a double-barreled question:
- Asks about two separate issues in a single question, making responses ambiguous (Correct answer)
- Uses leading language to push respondents toward a specific answer
- Is deliberately repeated to test reliability
- Contains technical jargon inaccessible to respondents
Correct answer: Asks about two separate issues in a single question, making responses ambiguous
A double-barreled question combines two issues in one item, so it is unclear which issue the respondent is answering.
Question 6: What distinguishes a mediating variable from a moderating variable?
- A mediator explains the mechanism of a relationship; a moderator affects its strength or direction (Correct answer)
- A mediator changes the direction of an effect; a moderator explains its cause
- A mediator is measured before treatment; a moderator is measured after
- A mediator is quantitative; a moderator is categorical
Correct answer: A mediator explains the mechanism of a relationship; a moderator affects its strength or direction
A mediator lies on the causal path between X and Y (explains how/why), while a moderator changes when or for whom the effect occurs.
Question 7: Which research design allows the study of rare phenomena by examining a single instance in depth?
- Meta-analysis
- Case study (Correct answer)
- Factorial experiment
- Systematic review
Correct answer: Case study
A case study provides in-depth examination of a single unit (person, organization, event), making it suited to rare or unique phenomena.
PRC Research Design & Methodology 3
A researcher measures income using brackets ($0–$25k, $25k–$50k, etc.).
What level of measurement is this?