The posthoc parameter

What it does

Post-hoc comparisons after ANOVA: "auto", "tukey", "games-howell", "bonferroni", "scheffe" or "none".

Empty — the default from Settings ("auto"). "auto" — Tukey HSD after a classic ANOVA, Games–Howell after a Welch ANOVA.

"none", FALSE or 0 — no post-hoc table; TRUE or 1 — "auto" (as a checkbox, a number or text).

Case and common spellings do not matter ("Bonferroni", "bonf", "hsd", "gh", "games howell", "sheffe"); an unknown value is an error that lists the variants.

The table is built only when the ANOVA is significant (p < 0.05) — a rule of ALS Stats: SPSS ONEWAY prints a requested posthoc table whatever the ANOVA shows.

With two groups no post-hoc table is built (it would repeat the ANOVA): when the ANOVA is significant, the report says "Posthoc tests are not performed: fewer than three groups" instead.

Values

Optional; default "auto".

Allowed values: "auto", "tukey", "games-howell", "bonferroni", "scheffe", "", "none" or FALSE (no table), TRUE ("auto")

In plain words

A teacher compared three classes, with averages 71, 74 and 79, and ANOVA said they differ. But which ones? With posthoc set to none, she gets only that answer. With auto, the usual setting, she also gets a table of pairs: class C stood apart from class A, while classes A and B were close. The other choices, such as bonferroni and scheffe, are stricter ways of checking the pairs. The table appears only when the gap between the classes does not look like luck, and never for just two classes, since there is only one pair.

Where you use it

Examples

Get it in your sheet

ALS Stats is a free add-on for Google Sheets™.

Install ALS Stats from Google Workspace Marketplace (opens in a new tab)