ci.lc.median.bs {statpsych} | R Documentation |
Computes a confidence interval for a linear contrast of medians in a between-subjects design using estimated medians and their standard errors. The sample median and standard error for each group can be computed using the ci.median1 function.
ci.lc.median.bs(alpha, m, se, v)
alpha |
alpha level for 1-alpha confidence |
m |
vector of estimated group medians |
se |
vector of group standard errors |
v |
vector of between-subjects contrast coefficients |
Returns a 1-row matrix. The columns are:
Estimate - estimated linear contrast of medians
SE - standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
Bonett DG, Price RM (2002). “Statistical inference for a linear function of medians: Confidence intervals, hypothesis testing, and sample size requirements.” Psychological Methods, 7(3), 370–383. ISSN 1939-1463, doi: 10.1037/1082-989X.7.3.370.
m <- c(46.13, 29.19, 30.32, 49.15) se <- c(6.361, 5.892, 4.887, 6.103) v <- c(1, -1, -1, 1) ci.lc.median.bs(.05, m, se, v) # Should return: # Estimate SE LL UL # [1,] 35.77 11.67507 12.88727 58.65273