Mixed Groups Factorial (2x2) ANOVA

Description

Performs a 2x2 mixed factorial ANOVA using the jmv package, with one between-groups factor and one within-groups factor. Returns within-subjects effects (WG main effect, BG x WG interaction), between-subjects effects (BG main effect), descriptive statistics for all cells, and estimated marginal means. All numeric values stored unrounded.

Usage

anova_factmg_answers(
  data,
  dv_vars,
  bg_iv,
  wg_name = "Measure",
  wg_labels = NULL,
  bg_labels = NULL,
  bg_levels = NULL
)

Arguments

data	A data frame in wide format (one row per subject).
dv_vars	Character vector of length 2. Names of the DV columns (one per WG condition).
bg_iv	Character string. Name of the between-groups IV column.
wg_name	Character string. Label for the within-groups factor (default: "Measure").
wg_labels	Character vector or NULL. Display labels for the WG conditions. Must be same length as dv_vars. Defaults to dv_vars.
bg_labels	Character vector or NULL. Display labels for BG levels.
bg_levels	Numeric or character vector or NULL. Explicit ordering of BG factor levels.

Value

A list with elements (all numeric values unrounded):

WithinSubjects

List with MainEffect_WG, Interaction, and Error, each containing F, p_value, df, ss, ms as applicable.

BetweenSubjects

List with MainEffect_BG and Error, each containing F, p_value, df, ss, ms as applicable.

Descriptives

Tibble with cell-level descriptive statistics including bg_level, wg_level, mean, sd, n, sem, bg_label, wg_label.

EMMs

List with BG and WG tibbles of estimated marginal means.

FactorInfo

List with wg_name, wg_labels, dv_vars, bg_levels, bg_labels, n_obs, group_ns.

Examples

library("psych350lab")

library(psych350data)
# Mixed factorial ANOVA: clark_grp (BG) x two repeated measures (WG)
# For example, rt_critics_score measured under two conditions
mg_results <- anova_factmg_answers(
  data = superman,
  dv_vars = c("rt_critics_score", "rt_audience_score"),
  bg_iv = "clark_grp",
  wg_name = "Rating Source",
  wg_labels = c("Critics", "Audience"),
  bg_labels = c("Under 6ft", "6ft or taller")
)