Behavioral Research: Statistical Methods
CG3.402Vinoo Alluri•Monsoon 2025-26•4 credits
100-mark mock paper · Paper 3
Duration: 120 min • Max marks: 100
Section A — MCQs (20 × 1 = 20 marks)
20 marks- 1.Which is true for a paired t-test? (a) Two independent samples (b) Two related samples, e.g., pre/post on same subjects (c) Three or more groups (d) Categorical DV1 m
- 2.What does the ratio MS_between/MS_within in ANOVA represent? (a) Effect size (b) F-statistic (c) Variance ratio (d) Both (b) and (c)1 m
- 3.In Bayesian terminology, the "evidence" or marginal likelihood P(D) acts as: (a) The prior (b) The normalizing constant (c) The posterior (d) The conditional1 m
- 4.Which of these correctly orders sample size effects on the t-distribution? (a) Smaller n → t closer to Normal (b) Larger n → t with heavier tails (c) Larger n → t approaches Normal (d) Sample size doesn't affect t1 m
- 5.A test with sensitivity 0.99 and specificity 0.99 in a population with 0.1% prevalence — P(disease | positive) ≈ ? (a) 99% (b) 50% (c) 9% (d) 1%1 m
- 6.Which is a sign of overfitting in regression? (a) High training R², much lower test R² (b) Both training and test R² high (c) Both low (d) Linear relationship1 m
- 7."The probability that this specific 95% CI contains μ is 95%" is: (a) The correct frequentist interpretation (b) A common misinterpretation; the procedure has 95% coverage, not a given interval (c) The Bayesian credible interval interpretation (d) Both (b) and (c)1 m
- 8.A Pearson correlation requires which scale type? (a) Nominal (b) Ordinal (c) Interval/Ratio (d) Any1 m
- 9.Stratified sampling is most useful when: (a) You have no subgroups (b) Subgroups differ on the outcome and proportions matter (c) Data is collected randomly (d) You want a convenience sample1 m
- 10.An ANOVA omnibus F is non-significant. You should: (a) Run all pairwise post-hoc tests anyway (b) Stop and conclude no group differences (c) Increase α (d) Switch to chi-square1 m
- 11."Ecological validity" refers to: (a) Internal consistency (b) Reliability over time (c) Generalizability to real-world settings (d) Statistical power1 m
- 12.A binomial(n = 20, p = 0.5) distribution has mean and variance: (a) 10 and 5 (b) 20 and 10 (c) 10 and 10 (d) 5 and 51 m
- 13.When comparing two correlated proportions (e.g., same people, two yes/no items), the appropriate test is: (a) Chi-square independence (b) McNemar's test (c) Pearson r (d) ANOVA1 m
- 14.The bias-variance trade-off in modeling refers to: (a) Bias and variance always equal (b) Reducing one tends to increase the other (c) Both can be eliminated together (d) Bias only applies to means1 m
- 15.A spider/radar plot is generally considered: (a) Highly informative (b) Often misleading due to area dependence on axis order (c) Standard for ANOVA (d) The only multivariate plot1 m
- 16.Which is the correct order from least informative to most informative measurement scale? (a) Interval, Ratio, Ordinal, Nominal (b) Nominal, Ordinal, Interval, Ratio (c) Ordinal, Nominal, Ratio, Interval (d) Ratio, Interval, Ordinal, Nominal1 m
- 17.A regression's residual plot shows a clear funnel shape (variance grows with X). This indicates: (a) Linearity (b) Normality (c) Heteroscedasticity (d) Multicollinearity1 m
- 18.Cronbach's α is a measure of: (a) Type I error (b) Internal consistency reliability (c) Construct validity (d) Effect size1 m
- 19.Which of the following is a non-parametric correlation measure? (a) Pearson r (b) Spearman ρ (c) Cohen's d (d) Eta-squared1 m
- 20.Power analyses are typically performed: (a) After data collection (b) Before data collection to plan sample size (c) Only in Bayesian analysis (d) To compute p-values1 m
Section B — MSQs (10 × 2 = 20 marks)
20 marks- 1.Which statements are correct about ANOVA? (a) F is a ratio of variances (b) ANOVA tests whether all means are equal (c) ANOVA assumes equal variances (d) Significant F identifies which groups differ (e) Effect size for ANOVA is η²2 m
- 2.Which are useful methods for visualizing distributions? (a) Boxplot (b) Histogram (c) Density plot (d) Pie chart (e) Raincloud plot2 m
- 3.Which are valid concerns about a published p = 0.049? (a) It is below 0.05, so it is automatically valid (b) Could result from p-hacking (c) Effect size might be tiny (d) Power might be low (e) Statistical significance ≠ practical significance2 m
- 4.Which are types of validity? (a) Internal (b) Inter-rater (c) External (d) Construct (e) Ecological2 m
- 5.Which conditions support causal inference? (a) Random assignment to conditions (b) Temporal precedence (c) Strong correlation (d) Ruling out plausible confounds (e) Replicability across contexts2 m
- 6.Which apply to the Chi-square test? (a) For categorical data (b) Computes (O − E)² / E summed over cells (c) Has degrees of freedom based on cells (d) Assumes expected cell counts ≥ 5 (e) Provides effect size called Cramér's V2 m
- 7.Which apply to Bayes Factor analysis? (a) Can provide evidence for H₀ (b) Depends on the prior (c) Is robust to optional stopping (d) Always > 1 (e) Quantifies evidence on a continuous scale2 m
- 8.Which are advantages of within-subjects designs? (a) Higher power (b) Fewer participants needed (c) No carryover effects (d) Controls for individual differences (e) Allows time-irreversible manipulations2 m
- 9.Which would be flagged as outliers by Tukey's 1.5×IQR rule? (a) A point at Q1 − 2.0×IQR (b) A point at Q3 + 1.6×IQR (c) A point at Q1 + 0.5×IQR (d) A point at median (e) A point at Q3 + 3×IQR2 m
- 10.Which strengthen external validity? (a) Diverse sample (b) Multiple settings (c) Strict laboratory control (d) Replication (e) Convenience sampling of college sophomores2 m
Section C — Short Descriptive (6 × 5 = 30 marks)
30 marksSection D — Long Descriptive (3 × 10 = 30 marks)
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