SIOP Research Methods & Data Analysis in I-O Psychology 2 — Questions and Answers
Question 1: A researcher wants to determine if a new training program causes improved performance. Which design best supports a causal inference?
- Cross-sectional survey
- Randomized controlled experiment (Correct answer)
- Correlational field study
- Meta-analysis of prior studies
Correct answer: Randomized controlled experiment
Only randomized controlled experiments allow causal inference by ruling out alternative explanations through random assignment.
Question 2: What does a negative skew in a distribution of performance scores indicate?
- Most scores cluster near the low end with a few very low outliers
- Most scores cluster near the high end with a tail toward the low end (Correct answer)
- The distribution is symmetric around the mean
- Variance is artificially inflated
Correct answer: Most scores cluster near the high end with a tail toward the low end
Negative skew means the tail extends to the left (lower scores), with most scores concentrated at the high end.
Question 3: In a multiple regression, which statistic indicates the unique contribution of each predictor while controlling for all others?
- Zero-order correlation
- R-squared
- Standardized beta coefficient (Correct answer)
- Eigenvalue
Correct answer: Standardized beta coefficient
Standardized beta coefficients reflect each predictor's unique contribution to the outcome after partialing out shared variance with other predictors.
Question 4: Which threat to internal validity occurs when participants change simply due to the passage of time during a study?
- Selection bias
- Instrumentation
- Maturation (Correct answer)
- Testing effect
Correct answer: Maturation
Maturation refers to natural changes in participants over time that are unrelated to the experimental treatment.
Question 5: An I-O psychologist uses experience sampling methodology (ESM). What is the primary advantage of this approach?
- Eliminates all measurement error
- Captures within-person variability across time and situations (Correct answer)
- Allows causal inference without random assignment
- Reduces the need for informed consent
Correct answer: Captures within-person variability across time and situations
ESM repeatedly measures individuals in real time, capturing fluctuations in mood, engagement, or behavior across contexts.
Question 6: When comparing the means of three or more independent groups, the appropriate statistical test is:
- Independent samples t-test
- Pearson correlation
- One-way ANOVA (Correct answer)
- Chi-square test of independence
Correct answer: One-way ANOVA
One-way ANOVA tests for differences among three or more group means while controlling the familywise Type I error rate.
Question 7: A researcher reports a 95% confidence interval for a mean difference of [0.2, 1.8]. What can be concluded?
- The null hypothesis is accepted at p < .05
- The effect size is large
- The population mean difference is likely not zero (Correct answer)
- The result is practically significant
Correct answer: The population mean difference is likely not zero
A 95% CI that excludes zero suggests the population mean difference is unlikely to be zero, supporting statistical significance.
SIOP Research Methods & Data Analysis in I-O Psychology 2
A researcher wants to determine if a new training program causes improved performance.
Which design best supports a causal inference?