smd {scan}

Standardized mean differences

Description

The smd() function provides various standardized mean effect sizes for single-case data.

Usage

smd(data, dvar, pvar, mvar, decreasing = FALSE, phases = c(1, 2))

Arguments

data

A single-case data frame. See scdf() to learn about this format.

dvar

Character string with the name of the dependent variable. Defaults to the attributes in the scdf file.

pvar

Character string with the name of the phase variable. Defaults to the attributes in the scdf file.

mvar

Character string with the name of the measurement time variable. Defaults to the attributes in the scdf file.

decreasing

If you expect data to be lower in the B phase, set decreasing = TRUE. Default is decreasing = FALSE.

phases

A vector of two characters or numbers indicating the two phases that should be compared. E.g., phases = c("A","C") or phases = c(2,4) for comparing the second to the fourth phase. Phases could be combined by providing a list with two elements. E.g., phases = list(A = c(1,3), B = c(2,4)) will compare phases 1 and 3 (as A) against 2 and 4 (as B). Default is phases = c(1,2).

Details

'sd cohen' is the (unweigted) average of the variance of phase A and B. 'sd Hedges' is the weighted average of the variance of phase A and B (with a degrees of freedom correction). 'Hedges' g' is the mean difference divided by 'sd Hedges'. 'Hedges' g correction' and 'Hedges' g durlak correction' are two approaches of correcting Hedges' g for small sample sizes. 'Glass' delta' is the mean difference divided by the standard deviation of the A-phase. 'Cohens d‘ is the mean difference divided by ’sd cohen'.

Author(s)

Juergen Wilbert

See Also

overlap(), describe()

Examples

smd(exampleAB)