Plot Solomon Posttest Cell Means with ggplot2

Displays posttest means and 95% confidence intervals for the four cells of a Solomon four-group design. Intervals use the t distribution with n - 1 degrees of freedom within each cell. For the model-adjusted means behind the sensitization contrast, see plot_sensitization().

Usage

plot_solomon_gg(y, treat, pretested)

Arguments

y

Numeric vector of posttest scores.

treat

Treatment indicator coded 0 = control and 1 = treatment.

pretested

Pretest indicator coded 0 = not pretested and 1 = pretested.

Value

A ggplot object.