Social Sciences & Humanities
Psychology & Behavioural Science
Experimental, clinical, and applied psychology. The field at the centre of the replication crisis and consequently the origin of much modern open-science practice: preregistration, registered reports, power analysis norms, and open materials and data sharing.
14 pages across 2 topic areas
Research Methods & Statistics
- Path Analysis: Direct, Indirect, and Total Effects
Path analysis is structural equation modeling with a structural model but no measurement model. This guide works a full path diagram end to end: stand…
- Test-Retest Reliability: Choosing the Retest Interval, and Checking for Drift
The retest interval is the design decision a test-retest coefficient cannot recover from. What the interval trades off, what COSMIN actually asks abou…
- The Wilcoxon Signed-Rank Test: Assumptions, Exact vs. Normal Approximation, and How to Report It
A decision guide to the Wilcoxon signed-rank test: what its null actually asserts (symmetry of the differences, not equal medians), why it is the pair…
- Inter-Rater Reliability: Choosing the Right Coefficient
A selection table from data type and rater design to the right agreement statistic – Cohen’s and weighted kappa, Fleiss’ kappa, ICC, Krippendorff’s al…
- Exploratory Factor Analysis: Extraction, Rotation, and How Many Factors to Retain
Exploratory factor analysis turns on three decisions usually made by accepting a default: extraction method, number of factors retained, and rotation.…
- Structural Equation Modeling (SEM): Fit Indices, Cut-Offs and Model Evaluation
A judgment-layer guide to evaluating structural equation models: which fit indices to report, why the widely cited Hu and Bentler cut-offs differ from…
- Average Variance Extracted (AVE): Calculation, the 0.50 Threshold, and Discriminant Validity
AVE is the mean proportion of indicator variance a construct explains rather than error. This guide gives the calculation, the origin and conventional…
- Questionnaire Design: Writing Survey Questions That Work
A construction guide to the questionnaire-design decisions that determine data quality: question wording, response-option and Likert scale design, que…
- Types of Validity in Research: Measurement Validity vs Design Validity
Measurement validity (face, content, construct, criterion) and design validity (internal, external, statistical-conclusion) are two distinct families …
- Power Analysis and Sample Size Calculation: A Complete Guide
How to run a power analysis to calculate sample size: the four interlocking quantities (effect size, alpha, power, N), a priori vs. post-hoc power, ch…
- Regression Analysis: Assumptions, Interpretation, and How to Report It
A practical guide to choosing between linear, logistic, and other regression models, checking each model’s assumptions, interpreting coefficients and …
- Cronbach’s Alpha: What It Measures, How to Interpret It, and When to Use Omega Instead
Cronbach’s alpha measures internal consistency, not unidimensionality or reliability in general — the most common misreading of the statistic. This gu…
- Mediator vs. Moderator: Which One Your Hypothesis Actually Needs
