PCB Research & Evidence-Based Practice 5 — Questions and Answers
Question 1: Which of the following best describes a 'type I error' in hypothesis testing?
- Failing to detect a true effect (false negative)
- Incorrectly concluding that an effect exists when it does not (false positive) (Correct answer)
- Using an inappropriate statistical test for the data type
- Recruiting an insufficient number of participants
Correct answer: Incorrectly concluding that an effect exists when it does not (false positive)
A Type I error (alpha error) occurs when a researcher rejects a true null hypothesis, concluding there is an effect when none actually exists.
Question 2: A practitioner uses 'PICO' format to structure a clinical question. What does the 'C' in PICO stand for?
- Context
- Comparison or control intervention (Correct answer)
- Cost-effectiveness
- Conceptual framework
Correct answer: Comparison or control intervention
In PICO, C stands for Comparison — the alternative intervention or control condition against which the primary intervention is evaluated.
Question 3: Which sampling method gives every member of the target population an equal chance of being selected for a study?
- Convenience sampling
- Purposive sampling
- Simple random sampling (Correct answer)
- Snowball sampling
Correct answer: Simple random sampling
Simple random sampling assigns each population member an equal probability of selection, minimizing selection bias and supporting external validity.
Question 4: When a systematic review uses meta-analytic techniques, the 'forest plot' visually displays which information?
- Participant demographic distributions across studies
- Effect sizes and confidence intervals for each included study and the pooled estimate (Correct answer)
- The risk of bias assessment scores for each study
- Chronological order of publication for included studies
Correct answer: Effect sizes and confidence intervals for each included study and the pooled estimate
A forest plot shows each study's effect size with its confidence interval as a horizontal line, plus a diamond representing the pooled meta-analytic estimate.
Question 5: A practitioner notices that participants in a study improved simply because they knew they were being observed, not because of the intervention itself. This phenomenon is called:
- Regression to the mean
- Placebo effect
- Hawthorne effect (Correct answer)
- Rosenthal effect
Correct answer: Hawthorne effect
The Hawthorne effect describes behavior change resulting from awareness of being observed rather than from the experimental intervention.
Question 6: Which research approach is most appropriate when the goal is to understand the lived experiences and meaning-making of participants rather than to quantify outcomes?
- Randomized controlled trial
- Survey with Likert-scale items
- Qualitative phenomenological study (Correct answer)
- Case-control study with matched pairs
Correct answer: Qualitative phenomenological study
Phenomenological qualitative research explores participants' subjective experiences in depth, making it ideal for understanding meaning rather than measuring frequency or magnitude.
Question 7: In evidence-based practice, 'clinical expertise' refers to which practitioner competency?
- The number of years the practitioner has been licensed
- The ability to conduct independent research studies
- The practitioner's proficiency and accumulated judgment from experience with clients (Correct answer)
- Familiarity with all published research in a given area
Correct answer: The practitioner's proficiency and accumulated judgment from experience with clients
Clinical expertise encompasses the skills, accumulated experience, and professional judgment a practitioner develops through direct practice, informing how research is applied to individual clients.
PCB Research & Evidence-Based Practice 5
Which of the following best describes a 'type I error' in hypothesis testing?