aipe_smd {mbir}

Accuracy in Parameter Estimation: Standardized Mean Difference

Description

Estimates sample size for paired or independent, two-sample study desings via Accuracy in Parameter Estimation. Calculates n so a given study is likely to obtain margin of error no larger than chosen target margin of error.

Usage

aipe_smd(moe, paired = c(TRUE, FALSE), conf.int, assur.lvl, r)

Arguments

moe

target margin of error in standard deviation units

paired

(character) logical indicator specifying if x and y are paired (TRUE) or independent (FALSE)

conf.int

(optional) confidence level of the interval. Defaults to 0.90

assur.lvl

(optional) desired level of assurance (percent experiments whose MOE is less than target MOE). Defaults to 0.99

r

(required if paired = TRUE) population correlation between the two measures

Details

Refer to vignette for further information.

References

Maxwell SE, Kelley K & Rausch JR. (2008). Sample size planning for statistical power and accuracy in parameter estimation. Annual Review of Psychology, 59, 537-563.

Kelley K & Rausch JR. (2006). Sample size planning for the standardized mean difference: Accuracy in parameter estimation via narrow confidence intervals. Psychological Methods, 11, 363–385.

Examples

aipe_smd(moe = 0.55, paired = TRUE, conf.int = .9, assur.lvl = .99, r = 0.75)