MSN Evidence-Based Practice and Research Methods 2 — Questions and Answers
Question 1: Which sampling method provides the best generalizability to the target population?
- Convenience sampling
- Simple random sampling (Correct answer)
- Purposive sampling
- Snowball sampling
Correct answer: Simple random sampling
Simple random sampling gives every member of the target population an equal chance of selection, minimizing selection bias and maximizing external validity.
Question 2: In a randomized controlled trial, blinding is used primarily to reduce which type of bias?
- Sampling bias
- Performance and detection bias (Correct answer)
- Attrition bias
- Publication bias
Correct answer: Performance and detection bias
Blinding prevents participants and/or investigators from knowing group assignment, reducing performance bias (altered behavior) and detection bias (subjective outcome measurement).
Question 3: A nurse practitioner implements a quality improvement project using the PDSA cycle. What does PDSA stand for?
- Plan, Develop, Study, Assess
- Plan, Do, Study, Act (Correct answer)
- Propose, Design, Survey, Analyze
- Prepare, Deploy, Sustain, Adapt
Correct answer: Plan, Do, Study, Act
The PDSA (Plan, Do, Study, Act) cycle is a continuous improvement framework used to test and implement changes in healthcare settings incrementally.
Question 4: Which level of measurement allows calculation of a meaningful zero point, permitting ratio comparisons?
- Nominal
- Ordinal
- Interval
- Ratio (Correct answer)
Correct answer: Ratio
Ratio measurement has all properties of interval measurement plus an absolute zero, making statements like 'twice as much' mathematically valid.
Question 5: Forest plots in a meta-analysis display confidence intervals for each study. What does it mean when a confidence interval crosses the line of no effect?
- The result is statistically significant
- The result is not statistically significant at the chosen alpha level (Correct answer)
- The study had insufficient internal validity
- The effect size is clinically negligible
Correct answer: The result is not statistically significant at the chosen alpha level
When a confidence interval crosses the null value (e.g., OR=1 or MD=0), the finding does not reach statistical significance because the range includes no difference.
Question 6: Which qualitative research method involves studying a group's culture and practices through immersive observation and interviews?
- Phenomenology
- Grounded theory
- Ethnography (Correct answer)
- Content analysis
Correct answer: Ethnography
Ethnography studies a cultural group in their natural environment through prolonged observation and interviews to understand shared meanings, values, and practices.
MSN Evidence-Based Practice and Research Methods 2
Which sampling method provides the best generalizability to the target population?