SWC: Smallest Worthwhile Change (SWC) for a set of athlete...

Description Usage Arguments Value References Examples

View source: R/SWC,MDC.R


Computes the SWC for each vector of measurements that is passed to the function, for the subject and trial vectors, the desired effect size of the change, and the desired method of calculating the between-subject standard deviation


SWC(subject, trial, ..., effect_size = 0.2, method = c("AVG", "MAX", "MIN"))



The vector of athletes who recorded the results for each metric (can be a numeric or factor variable)


The vector that represents which trial each measurement came from


Numeric vectors that represent the metrics for which the SWC should be computed. These vectors hold the scores that each athlete recorded for each respective metric (at least one metric must be passed to the function).


The proportion of the within-subject standard deviation that is defined as a worthwhile change. The default value is 0.2, but users can input any positive value into this argument.


The user's choice of how the between-athlete SD should be computed in the formula for the SWC. If set to AVG, each athlete's values will be averaged before the SD of these between-athlete averages is computed. If MAX is selected, then only the highest value each athlete records will be included in the computation of the between-athlete SD. Conversely, if the user indicates MIN, then only the lowest value each athlete records will be used to compute the between-athlete SD.


A data frame, with the name of each metric situated above its calculated SWC


Bernards, J., Sato, K., Haff, G., & Bazyler, C. (2017). Current Research and Statistical Practices in Sport Science and a Need for Change. Sports, 5(4), 87.


subject <- c(1, 1, 1, 2, 2, 2, 3, 3, 3)
trial <- c(1, 2, 3, 1, 2, 3, 1, 2, 3)
metric_1 <- c(250, 258, 252, 279, 270, 277, 218, 213, 218)
metric_2 <- c(10, 7, 10, 14, 18, 17, 11, 7, 8)
metric_3 <- c(1214, 1276, 1289, 1037, 1010, 1069, 1481, 1465, 1443)
SWC(subject, trial, metric_1, metric_2, metric_3, effect_size = 0.2, method = 'AVG')

psr documentation built on Aug. 13, 2021, 5:08 p.m.