Effect Size Descriptions

library(irtools)

There are several generic effect sizes descriptions available for use in this package. These include the standard effect sizes specified by Cohen.

Cohen’s Effect Sizes

cohen_effect_sizes %>% 
  knitr::kable(booktab=TRUE)

effect_size	effect_description
2.0	huge
1.2	very large
0.8	large
0.5	medium
0.2	small
0.1	very small

the compare_chi_square2 function utilises those effect sizes from the cohen_effect_sizes data set when making a determination on the magnitude of the effect.

Kraft’s Effect Sizes

Kraft’s effect sizes are based on research on the effect sizes of educational interventions and are much smaller than those specified by Cohen. These effect sizes are used for the standardized effect graph (aka the tie-fighter graph).

kraft_effect_sizes %>% 
  knitr::kable(booktab=TRUE)

effect_size	effect_description
0.201	large
0.200	medium
0.050	small