Module stikpetP.other.thumb_cohen_w

Functions

def th_cohen_w(w, qual='cohen')

Rule Of Thumb For Cohen W

Simple function to use a rule-of-thumb for the Cohen w effect size.

The measure is also described at PeterStatistics.com

Parameters

w : float

the Cohen w value

qual : {"cohen"}, optional

indication which set of rule-of-thumb to use. Currently only "cohen"

Returns

pandas.DataFrame

A dataframe with the following columns:

• classification, the qualification of the effect size
• reference, a reference for the rule of thumb used

Notes

Cohen's rule of thumb for Cohen w (1988, p. 227):

|w|	Interpretation
0.00 < 0.10	negligible
0.10 < 0.30	small
0.30 < 0.50	medium
0.50 or more	large

Before, After and Alternatives

Before using this function you need to obtain a Cohen w value: * es_cohen_w to obtain Cohen w

References

Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). L. Erlbaum Associates.

Author

Made by P. Stikker

Companion website: https://PeterStatistics.com
YouTube channel: https://www.youtube.com/stikpet
Donations: https://www.patreon.com/bePatron?u=19398076

Examples

>>> es = 0.6
>>> th_cohen_w(es)
  classification             reference
0          large  Cohen (1988, p. 227)

Expand source code

def th_cohen_w(w, qual="cohen"):
    '''
    Rule of thumb for Cohen w
    --------------------------
    
    Simple function to use a rule-of-thumb for the Cohen w effect size.

    The measure is also described at [PeterStatistics.com](https://peterstatistics.com/Terms/EffectSizes/CohenW.html)
    
    Parameters
    ----------
    w : float
        the Cohen w value
    qual : {"cohen"}, optional 
        indication which set of rule-of-thumb to use. Currently only "cohen"
    
    Returns
    -------
    pandas.DataFrame
        A dataframe with the following columns:
    
        * *classification*, the qualification of the effect size
        * *reference*, a reference for the rule of thumb used
    
    Notes
    -----
    Cohen's rule of thumb for Cohen w (1988, p. 227):
    
    |\\|w\\|| Interpretation|
    |---|----------|
    |0.00 < 0.10 | negligible |
    |0.10 < 0.30 | small |
    |0.30 < 0.50 | medium |
    |0.50 or more | large |
    
    Before, After and Alternatives
    ------------------------------
    Before using this function you need to obtain a Cohen w value:
    * [es_cohen_w](../effect_sizes/eff_size_cohen_w.html#es_cohen_w) to obtain Cohen w
    
    References
    ----------
    Cohen, J. (1988). *Statistical power analysis for the behavioral sciences* (2nd ed.). L. Erlbaum Associates.
    
    Author
    ------
    Made by P. Stikker
    
    Companion website: https://PeterStatistics.com  
    YouTube channel: https://www.youtube.com/stikpet  
    Donations: https://www.patreon.com/bePatron?u=19398076
    
    Examples
    -------
    >>> es = 0.6
    >>> th_cohen_w(es)
      classification             reference
    0          large  Cohen (1988, p. 227)
    
    '''
    
    if (qual=="cohen"):
        ref = "Cohen (1988, p. 227)"
        if (abs(w)<0.1):
            qual = "negligible"
        elif (abs(w)<0.3):
            qual = "small"
        elif (abs(w)<0.5):
            qual = "medium"
        else:
            qual = "large"
            
    results = pd.DataFrame([[qual, ref]], columns=["classification", "reference"])
    
    return(results)