PRC Data Collection & Analysis 3 — Questions and Answers
Question 1: What is the main advantage of a longitudinal study design over a cross-sectional design?
- Lower cost and faster completion
- Ability to track changes in the same subjects over time (Correct answer)
- Elimination of sampling error
- Greater generalizability to diverse populations
Correct answer: Ability to track changes in the same subjects over time
Longitudinal designs follow the same subjects across time, enabling researchers to observe change, development, and causal sequences.
Question 2: Which statistical test is appropriate for comparing means across three or more independent groups?
- Chi-square test
- Paired t-test
- One-way ANOVA (Correct answer)
- Pearson correlation
Correct answer: One-way ANOVA
One-way ANOVA tests whether the means of three or more independent groups differ significantly, controlling the overall Type I error rate.
Question 3: A p-value of 0.03 means:
- There is a 3% chance the research hypothesis is true
- There is a 3% probability of obtaining the observed result if the null hypothesis is true (Correct answer)
- The effect size is 3%
- 97% of the variance is explained by the model
Correct answer: There is a 3% probability of obtaining the observed result if the null hypothesis is true
A p-value indicates the probability of observing results at least as extreme as those found, assuming the null hypothesis is true.
Question 4: In qualitative research, 'saturation' refers to:
- Collecting data until budget is exhausted
- The point at which new data no longer yields new themes or insights (Correct answer)
- Achieving a 100% response rate
- Transcribing all recorded interviews
Correct answer: The point at which new data no longer yields new themes or insights
Theoretical saturation occurs when additional data collection produces no new categories or themes, signaling sufficient depth.
Question 5: Which of the following BEST describes 'triangulation' in research?
- Using a geometric sampling grid for geographic studies
- Cross-validating findings by using multiple data sources, methods, or analysts (Correct answer)
- Applying three-stage cluster sampling
- Dividing respondents into three equal groups
Correct answer: Cross-validating findings by using multiple data sources, methods, or analysts
Triangulation strengthens validity by corroborating findings through multiple and independent data sources, methods, or theoretical perspectives.
Question 6: An interval scale differs from a ratio scale in that interval scales:
- Have no meaningful order
- Lack a true zero point (Correct answer)
- Cannot be used in arithmetic operations
- Only contain whole numbers
Correct answer: Lack a true zero point
Interval scales have equal distances between values but no absolute zero, so ratios between values are not meaningful (e.g., temperature in Celsius).
Question 7: What does 'inter-rater reliability' assess?
- Consistency of a measure across different time points
- Agreement between two or more independent coders or raters (Correct answer)
- The degree to which a scale measures what it intends to measure
- Correlation between two different survey instruments
Correct answer: Agreement between two or more independent coders or raters
Inter-rater reliability measures the extent to which independent observers or coders produce consistent results when evaluating the same material.
PRC Data Collection & Analysis 3
What is the main advantage of a longitudinal study design over a cross-sectional design?