Coefficient of variation (CV). |
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This expresses standard deviation as a percentage of the mean value of a set of observations. The resulting value (between 0-1) describes the variability between observations, with lower values indicating less variability. CV is traditionally used to describe the variability of an outcome in a single set, e.g. the variability of feeding behavior in a group of cattle. Applying this analysis to reliability would be tricky, as it would use 2 sets of paired observations. This would require first calculating the mean difference between each set of paired observations, then calculating a CV on all mean differences. Interpreting this CV would also be challenging, as it would only show if variance existed between both observers, but would not show true agreement, and would not identify if one observer is more variable than the other.
This descriptive analysis should not be used in isolation, and instead may be used to complement a formal statistical test (e.g. ICC for continuous data). A Bland-Altman plot may be a more useful descriptive analysis to use.
This descriptive analysis should not be used in isolation, and instead may be used to complement a formal statistical test (e.g. ICC for continuous data). A Bland-Altman plot may be a more useful descriptive analysis to use.
