10.4 Effect Size Definitions
There are several generic effect sizes descriptions available for use in this package. These include the standard effect sizes specified by Cohen.
10.4.1 Cohen’s Effect Sizes
| 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.
10.4.2 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).
| effect_size | effect_description |
|---|---|
| 0.201 | large |
| 0.200 | medium |
| 0.050 | small |
10.4.3 Summary of irtools
This package has a ton of different utility functions. More details are available at the package website at http://groups.wfu.edu/ir/tools/irtools/index.html. Additionally, this package should grow and be expanded as more helper functions or repetitive items are identified.