Choosing a Procedure

Not sure which analysis you need? Start from what you have and what you want to know. Find the row that matches and follow the link.

I want to describe / summarise

You have	Use
One categorical variable — how often each value occurs	Frequencies
Scale variables — mean, SD, range side by side	Descriptives
One scale variable — full distribution, normality, outliers	Explore
A breakdown of a scale variable by groups (no test)	Means
The shape of a distribution, visually	Histogram / Boxplot

I want to compare groups (a scale outcome)

Groups	Assumptions OK?	Use
One mean vs a fixed value	yes	One-Sample T Test
Two independent groups	yes	Independent-Samples T Test
Two independent groups	no (non-normal)	Mann-Whitney U
Two related measurements	yes	Paired-Samples T Test
Two related measurements	no	Wilcoxon / Sign
Three+ independent groups	yes	One-Way ANOVA
Three+ independent groups	no	Kruskal-Wallis
Three+ related measurements	no	Friedman
Several factors, ± covariates	yes	GLM

I want to relate two categorical variables

→ Crosstabs (chi-square and association measures), or Custom Tables for a bespoke pivot.

I want to measure association between scale variables

→ Correlate (Pearson, Spearman, Kendall; partial to control for other variables).

I want to predict an outcome from predictors

Outcome type	Use
Continuous	Linear regression
Binary (yes/no)	Binary logistic
Count	Poisson / Negative Binomial
Unordered categories	Multinomial
Ordered categories	Ordinal
Continuous, clustered/repeated data	Mixed model
Known groups, from scale predictors	Discriminant

I want to find structure / reduce variables

Goal	Use
Do these items form one reliable scale?	Reliability
Reduce many variables to a few factors	Factor
Test a hypothesized factor structure	Confirmatory Factor Analysis
Group cases into a fixed number of clusters	K-Means
Group cases, see the structure	Hierarchical
Group cases, let the count be chosen	Two-Step

I have time-to-event or time-ordered data

You have	Use
Time until an event, with censoring	Kaplan-Meier / Cox
A series ordered in time, want its structure	Autocorrelation
A series ordered in time, want a forecast	ARIMA / SARIMA

I want to combine results across studies

→ Meta-Analysis (one row per study — an effect size and its standard error — pooled under fixed- and random-effects models, with heterogeneity statistics, a forest plot and a funnel plot with Egger's test).

Still unsure?

Ask the AI assistant in plain language — describe your data and your question, and it will pick and run the appropriate procedure. See also the glossary for unfamiliar terms.