CPI Study Design & Methodology 2

Question 1

A researcher wants to determine whether a new drug causes fewer side effects than the standard treatment. Which study design provides the strongest causal evidence?

Accepted Answer

Randomized controlled trial

Answer

Randomized controlled trials randomly assign participants to treatment groups, minimizing confounding and providing the strongest causal evidence.

Question 2

In a factorial design, a researcher tests two drugs (A and B) each at two doses (high and low). How many treatment conditions exist?

Accepted Answer

4

Answer

A 2×2 factorial design creates 4 conditions: A-high, A-low, B-high, and B-low, allowing analysis of main effects and interactions.

Question 3

Which sampling method divides a population into subgroups and randomly selects participants from each subgroup proportionally?

Accepted Answer

Stratified random sampling

Answer

Stratified random sampling divides the population into strata and samples proportionally from each, improving representativeness.

Question 4

A study enrolls participants based on their disease status and then looks back to identify past exposures. This is best described as:

Accepted Answer

Case-control study

Answer

Case-control studies select participants based on outcome (cases vs. controls) and retrospectively assess prior exposures.

Question 5

When a researcher measures the same variable using two different instruments and compares results, they are assessing:

Accepted Answer

Convergent validity

Answer

Convergent validity is demonstrated when two measures of the same construct produce similar results.

(CPI) Certified Principal Investigator Practice Test

(CPI) Certified Principal Investigator Practice Test

CPI Study Design & Methodology 2