07-appendix.Rmd

# Appendix: Measurement Levels & Summary Statistics {-}

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Statistic /\               Categorical\   Ranked\     Discrete/Counts\   Continuous\
Parameter                  *Nominal*      *Ordinal*   *Interval/Ratio*   *Interval/Ratio* 
------------------------- -------------- ----------- ------------------ ------------------
Data set size (n)\         Y\              Y\          Y\                  Y\ 
Percent / Frequency\       Y\              Y\          Y\                  Y\ 
Count or rate\             Y\              Y\          Y\                  Y\ 
Categories (levels)\       Y\              Y\          Y\                  Y\ 
Mode\                      Y\              Y\          Y\                  Y\ 
Median\                    *No*\              Y\          Y\                  Y\ 
Interquartile range\       *No*\              Y\          Y\                  Y\ 
Median absolute deviation\ *No*\              Y\          Y\                  Y\ 
Range\                     *No*\              Y\          Y\                  Y\ 
Minimum/maximum value\     *No*\              Y\          Y\                  Y\ 
Quantiles\                 *No*\              Y\          Y\                  Y\ 
Mean (average)\            *No*\              *No*\          Y\                 Y\ 
Standard deviation\        *No*\              *No*\          Y\*\               Y\*\ 
Coefficient of variation\  *No*\              *No*\          Y\*\               Y\*\ 
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\* You must use the correct distribution (proper mean-variance relationship) to ensure you get the correct standard deviation; most software defaults to calculating the standard deviation for a normally-distributed sample, which could be incorrect for certain kinds of count, rate, or proportion data, for example.