volker (version 3.1.0)

effect_metrics_items_grouped: Compare groups for each item by calculating F-statistics and effect sizes

Description

The models are fitted using stats::lm. ANOVA of type II is computed for each fitted model using car::Anova. Eta Squared is calculated for each ANOVA result using effectsize::eta_squared.

Usage

effect_metrics_items_grouped(
  data,
  cols,
  cross,
  labels = TRUE,
  clean = TRUE,
  ...
)

Value

A volker tibble with the following statistical measures:

• Eta-squared: Effect size indicating the proportion of variance in the dependent variable explained by the predictor.

• Eta: Root of Eta-squared, a standardized effect size.

• n: Number of cases the calculation is based on.

• F: F-statistic from the linear model.

• p: p-value for the statistical test.

• stars: Significance stars based on p-value (*, **, ***).

Arguments

data

A tibble containing item measures.

cols

Tidyselect item variables (e.g. starts_with...).

cross

The column holding groups to compare.

labels

If TRUE (default) extracts labels from the attributes, see codebook.

clean

Prepare data by data_clean.

...

Placeholder to allow calling the method with unused parameters from effect_metrics.

Examples

library(volker)
data <- volker::chatgpt

effect_metrics(data, starts_with("cg_adoption_"), adopter)