CHES Evaluation and Research Methods 3 — Questions and Answers
Question 1: When conducting a focus group for health program evaluation, the ideal group size is typically:
- 2–4 participants
- 6–10 participants (Correct answer)
- 12–15 participants
- 20–25 participants
Correct answer: 6–10 participants
Groups of 6–10 participants allow enough diversity of opinion while still enabling meaningful group discussion.
Question 2: A CHES professional observes a significant difference in test scores (p = 0.03). What does this p-value indicate?
- There is a 3% chance the intervention caused the effect
- There is a 3% probability of obtaining these results if the null hypothesis is true (Correct answer)
- The effect size is large
- The study has 97% power
Correct answer: There is a 3% probability of obtaining these results if the null hypothesis is true
A p-value of 0.03 means there is a 3% probability that the observed difference occurred by chance if the null hypothesis were true.
Question 3: Which ethical principle requires that research participants understand the nature of the study before agreeing to participate?
- Beneficence
- Justice
- Informed consent (Correct answer)
- Confidentiality
Correct answer: Informed consent
Informed consent ensures participants are fully informed about study procedures, risks, and their right to withdraw before agreeing to participate.
Question 4: Construct validity refers to the extent to which an instrument:
- Produces consistent results over time
- Accurately measures the theoretical concept it is designed to measure (Correct answer)
- Covers all relevant content domains
- Predicts future health behavior accurately
Correct answer: Accurately measures the theoretical concept it is designed to measure
Construct validity assesses whether a measurement tool truly captures the underlying theoretical construct it represents.
Question 5: In the CDC evaluation framework, 'stakeholder engagement' is emphasized because:
- It reduces the cost of data collection
- It ensures that evaluation findings are used and meet the needs of those involved (Correct answer)
- It increases statistical power of the study
- It eliminates the need for a control group
Correct answer: It ensures that evaluation findings are used and meet the needs of those involved
Engaging stakeholders ensures the evaluation is relevant, credible, and that findings will be acted upon by those with a stake in the program.
Question 6: Which sampling method ensures every member of the population has an equal chance of selection?
- Convenience sampling
- Purposive sampling
- Simple random sampling (Correct answer)
- Snowball sampling
Correct answer: Simple random sampling
Simple random sampling gives each population member an equal and independent chance of being selected, supporting generalizability.
Question 7: A health educator uses a pre-validated instrument from a prior study. This practice primarily supports:
- Ecological validity
- Measurement reliability and comparability across studies (Correct answer)
- Convenience of data entry
- Reduction of participant burden
Correct answer: Measurement reliability and comparability across studies
Using validated instruments improves reliability and allows meaningful comparison of results with other studies using the same tool.
CHES Evaluation and Research Methods 3
When conducting a focus group for health program evaluation, the ideal group size is typically: