Understand every analysis
Search the implemented methods. Every page states the design requirements, assumptions, formula, interpretation, and primary references.
Generalized estimating equations
regressionEstimate population-average associations for clustered or repeated responses.
Bayesian generalized mixed model
regressionModel subject-specific associations for repeated binary or count outcomes.
Descriptive statistics
descriptiveUse when the outcome/model family is not yet clear or the needed model is not implemented.
Welch's t-test
meansCompare a continuous outcome between exactly two independent groups without assuming equal variances.
Student's t-test
meansCompare two independent group means when equal variances are defensible.
Paired t-test
meansCompare two measurements from the same unit, person, or matched pair.
One-sample t-test
meansCompare one continuous variable against a known reference value.
Binomial test
categoricalCompare a binary outcome proportion against a specified reference proportion.
Mann–Whitney U
nonparamCompare two independent groups when rank/ordinal behavior is more appropriate than means.
Wilcoxon signed-rank
nonparamCompare paired ordinal or non-normal continuous measurements.
Kruskal–Wallis
nonparamCompare three or more independent groups using ranks.
Friedman test
nonparamCompare three or more paired or repeated measurements using ranks.
One-way ANOVA
meansCompare a continuous outcome across three or more groups.
Factorial ANOVA
meansEstimate main effects and interactions for multiple categorical factors.
Repeated-measures ANOVA
meansCompare three or more repeated measurements from the same unit.
ANCOVA
regressionCompare adjusted group means while controlling continuous covariates.
Pearson correlation
associationMeasure linear association between two continuous variables.
Covariance
associationDescribe how two numeric variables vary together in their original units.
Spearman correlation
associationMeasure monotone association using ranks.
Kendall's tau
associationMeasure ordinal or monotone association with a rank-based coefficient robust to small samples.
Point-biserial correlation
associationMeasure association between one continuous variable and one binary variable.
Eta correlation ratio
associationMeasure association between a continuous variable and a categorical grouping variable.
Partial correlation
associationMeasure association between two continuous variables after linear adjustment for covariates.
Chi-square test
categoricalTest association between two categorical variables.
Fisher's exact test
categoricalAnalyze a small 2x2 contingency table.
McNemar's test
categoricalCompare paired binary responses.
Linear regression (OLS)
regressionModel a continuous outcome with one or more predictors.
Logistic regression
regressionModel a binary outcome with one or more predictors.
Ridge regression
regressionFit a linear regression when predictors are correlated and coefficient shrinkage is useful.
Lasso regression
regressionFit a linear regression with coefficient shrinkage and possible variable selection.
Poisson regression
regressionModel count outcomes or rates.
Principal component analysis (PCA)
unsupervisedReduce several correlated numeric features to a smaller set of variance directions.
K-means clustering
unsupervisedExplore whether observations form compact groups across several numeric features.
Exploratory factor analysis
unsupervisedEstimate latent factors that explain correlations among observed numeric variables.
Reliability analysis (Cronbach's alpha)
unsupervisedAssess the internal consistency of multiple items intended to measure one construct.
Hierarchical clustering
unsupervisedExplore nested group structure without fixing a cluster count in advance.
ROC analysis
associationEvaluate how a numeric score separates a binary outcome across thresholds.
Power and sample-size calculation
meansPlan sample size or estimate power for a mean comparison.
Kaplan–Meier + log-rank
survivalCompare survival curves between groups.
Cox proportional hazards
survivalModel time-to-event outcomes with covariates.
Linear mixed-effects model
regressionModel continuous outcomes with repeated or clustered observations.
Cohen's kappa
categoricalMeasure agreement between two categorical ratings of the same observations.
Fleiss' kappa
categoricalMeasure categorical agreement across three or more raters.
Intraclass correlation (ICC)
associationAssess absolute agreement among numeric ratings or repeated measurements.
Equivalence test (TOST)
meansTest whether a two-group mean difference is small enough to be practically equivalent.
Moderation analysis
regressionTest whether one numeric predictor changes the association of another with an outcome.
Mediation analysis
regressionEstimate an indirect association through a numeric mediator.
Multinomial logistic regression
regressionModel an unordered categorical outcome with three or more levels.