Confidence intervals for a paired-samples standardized mean difference

Computes confidence intervals for a population standardized mean difference in a paired-samples design. A square root unweighted variance standardizer and single measurement standard deviation standardizers are used. Equality of variances is not assumed.

For more details, see Section 4.3 of Bonett (2021, Volume 1)

Usage

ci.stdmean.ps(alpha, m1, m2, sd1, sd2, cor, n)

Arguments

alpha: alpha level for 1-alpha confidence
m1: estimated mean for measurement 1
m2: estimated mean for measurement 2
sd1: estimated standard deviation for measurement 1
sd2: estimated standard deviation for measurement 2
cor: estimated correlation between measurements
n: sample size

Value

Returns a 3-row matrix. The columns are:

Estimate - estimated standardized mean difference
adj Estimate - bias adjusted standardized mean difference estimate
SE - standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval

References

Bonett DG (2008). “Confidence intervals for standardized linear contrasts of means.” Psychological Methods, 13(2), 99–109. ISSN 1939-1463, doi:10.1037/1082-989X.13.2.99 .

Bonett DG (2021). Statistical Methods for Psychologists https://dgbonett.sites.ucsc.edu/.

Examples

ci.stdmean.ps(.05, 602.4, 705.6, 33.17, 51.08, .769, 8)
#>                             Estimate adj Estimate      SE      LL      UL
#> Unweighted standardizer:     -2.3963      -2.2185 0.65209 -3.6744 -1.1182
#> Measurement 1 standardizer:  -3.1112      -2.7656 0.91362 -4.9019 -1.3206
#> Measurement 2 standardizer:  -2.0204      -1.7959 0.59328 -3.1832 -0.8576

# Should return:
#                             Estimate adj Estimate      SE      LL      UL
# Unweighted standardizer:     -2.3963      -2.2185 0.65209 -3.6744 -1.1182
# Measurement 1 standardizer:  -3.1112      -2.7656 0.91362 -4.9019 -1.3206
# Measurement 2 standardizer:  -2.0204      -1.7959 0.59328 -3.1832 -0.8576