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

In volker: High-Level Functions for Tabulating, Charting and Reporting Survey Data

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,
  ...
)

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.

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 (*, **, ***).

Examples

library(volker)
data <- volker::chatgpt

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

volker documentation built on April 12, 2025, 9:16 a.m.