PCB Research & Evidence-Based Practice 3 — Questions and Answers
Question 1: A researcher finds a statistically significant result with a p-value of 0.001 but a very small effect size (d = 0.05). What is the most accurate interpretation?
- The finding is both statistically and practically significant
- The result is statistically significant but may have little practical importance (Correct answer)
- The small p-value invalidates the effect size calculation
- The study must have had a very small sample size
Correct answer: The result is statistically significant but may have little practical importance
Statistical significance does not equal practical significance; a very small effect size suggests the intervention has minimal real-world impact despite the low p-value.
Question 2: Which research methodology involves the intensive study of a single individual or unit over time, commonly used in applied behavior analysis?
- Between-group experimental design
- Cross-sectional cohort study
- Single-case experimental design (Correct answer)
- Grounded theory qualitative study
Correct answer: Single-case experimental design
Single-case experimental designs (e.g., ABAB, multiple baseline) allow practitioners to evaluate interventions for individuals by systematically manipulating and measuring variables.
Question 3: When evaluating research for evidence-based practice, which factor is LEAST relevant to assessing study quality?
- Sample size and statistical power
- Date the journal article was published online (Correct answer)
- Risk of bias in participant selection
- Reliability of outcome measures
Correct answer: Date the journal article was published online
Publication date alone does not determine study quality; bias, sample size, and measurement reliability are far more critical quality indicators.
Question 4: A practitioner conducts a literature search and finds that all published studies on a treatment show positive results. Which research artifact should be considered?
- Measurement invariance
- Publication bias (Correct answer)
- Type II error inflation
- Regression to the mean
Correct answer: Publication bias
Publication bias occurs when studies with positive results are more likely to be published, leading to an inflated view of an intervention's effectiveness.
Question 5: Which of the following best describes 'external validity' in the context of research?
- The accuracy of the instruments used to collect data
- The degree to which study findings can be generalized to other populations and settings (Correct answer)
- Whether the study was peer-reviewed
- The consistency of findings across multiple raters
Correct answer: The degree to which study findings can be generalized to other populations and settings
External validity refers to the extent to which research findings can be applied beyond the specific sample and conditions of the original study.
Question 6: In a research article, the 'confidence interval' around an effect size estimate represents which concept?
- The probability the study hypothesis is correct
- A range of values within which the true population parameter likely falls (Correct answer)
- The minimum detectable effect for the study
- The percentage of participants who improved
Correct answer: A range of values within which the true population parameter likely falls
A 95% confidence interval means that if the study were repeated many times, 95% of calculated intervals would contain the true population parameter.
Question 7: When a practitioner searches databases for relevant research, using Boolean operators such as AND, OR, and NOT is primarily intended to:
- Limit the search to open-access articles only
- Refine and expand the search to identify the most relevant studies (Correct answer)
- Exclude studies published before a certain year
- Identify studies from specific geographic regions
Correct answer: Refine and expand the search to identify the most relevant studies
Boolean operators allow searchers to combine keywords strategically, broadening or narrowing retrieval to maximize relevant results.
PCB Research & Evidence-Based Practice 3
A researcher finds a statistically significant result with a p-value of 0.001 but a very small effect size (d = 0.05).
What is the most accurate interpretation?