PCB Research & Evidence-Based Practice 2 — Questions and Answers
Question 1: Which research design is best suited for establishing a causal relationship between an intervention and an outcome in PCB design practice?
- Cross-sectional survey
- Case study
- Randomized controlled trial (Correct answer)
- Retrospective chart review
Correct answer: Randomized controlled trial
Randomized controlled trials (RCTs) use random assignment to minimize confounding variables, making them the gold standard for establishing causation.
Question 2: A practitioner wants to summarize and synthesize findings from multiple primary studies on a topic. Which type of research product is most appropriate?
- Single case experimental design
- Systematic review or meta-analysis (Correct answer)
- Descriptive case report
- Pilot feasibility study
Correct answer: Systematic review or meta-analysis
Systematic reviews and meta-analyses pool data across multiple studies to provide the highest-level summary of evidence on a question.
Question 3: In evidence-based practice, the term 'internal validity' refers to which of the following?
- Generalizability of results to other populations
- The degree to which a study accurately measures what it intends to measure
- The extent to which observed outcomes are due to the intervention rather than extraneous factors (Correct answer)
- Consistency of results across different raters
Correct answer: The extent to which observed outcomes are due to the intervention rather than extraneous factors
Internal validity reflects the confidence that changes in the dependent variable were caused by the independent variable, not by confounds.
Question 4: A practitioner adopts an intervention that has strong research support but modifies it significantly for local use. What critical step should follow?
- Abandon the intervention and select a different evidence-based practice
- Monitor client outcomes systematically to evaluate effectiveness of the modified approach (Correct answer)
- Publish the modification without further data collection
- Use the same outcome measures as the original study regardless of relevance
Correct answer: Monitor client outcomes systematically to evaluate effectiveness of the modified approach
When an evidence-based practice is adapted, systematic outcome monitoring is essential to determine whether the modified version remains effective.
Question 5: Which statistical concept indicates the probability that a study's results are due to chance rather than a true effect?
- Effect size
- Confidence interval
- p-value (Correct answer)
- Standard deviation
Correct answer: p-value
The p-value represents the probability of observing results at least as extreme as those found, assuming the null hypothesis is true.
Question 6: What is the primary purpose of a control group in an experimental research design?
- To increase the sample size of the study
- To provide a comparison baseline for evaluating the effect of the intervention (Correct answer)
- To represent participants who received the most intensive treatment
- To identify outliers in the data set
Correct answer: To provide a comparison baseline for evaluating the effect of the intervention
A control group receives no intervention (or standard care), allowing researchers to compare outcomes and attribute differences to the experimental treatment.
Question 7: Which level of evidence is generally considered lowest on the evidence hierarchy?
- Meta-analysis of randomized controlled trials
- Single randomized controlled trial
- Cohort study
- Expert opinion or anecdotal report (Correct answer)
Correct answer: Expert opinion or anecdotal report
Expert opinion and anecdotal reports sit at the base of evidence hierarchies because they lack systematic methodology and are subject to bias.
PCB Research & Evidence-Based Practice 2
Which research design is best suited for establishing a causal relationship between an intervention and an outcome in PCB design practice?