ci.random.anova: Confidence intervals for parameters of one-way random effects...

In statpsych: Statistical Methods for Psychologists

Confidence intervals for parameters of one-way random effects ANOVA

Description

Computes estimates and confidence intervals for four parameters of the one-way random effects ANOVA: 1) the superpopulation grand mean, 2) the square-root within-group variance component, 3) the square-root between-group variance component, and 4) the omega-squared coefficient. This function assumes equal sample sizes.

Usage

ci.random.anova(alpha, m, sd, n)

Arguments

alpha	1 - alpha confidence
m	vector of estimated group means
sd	vector of estimated group standard deviations
n	common sample size in each group

Value

Returns a 4-row matrix. The rows are:

• Grand mean - the mean of the superpopulation of means

• Within SD - the square-root within-group variance component

• Between SD - the square-root between-group variance component

• Omega-squared - the omega-squared coefficient

The columns are:

• Estimate - estimate of parameter

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

Examples

m <- c(56.1, 51.2, 60.3, 68.2, 48.9, 70.5)
sd <- c(9.45, 8.79, 9.71, 8.90, 8.31, 9.75)
ci.random.anova(.05, m, sd, 20)

# Should return:
#                 Estimate         LL         UL
# Grand mean     59.200000 49.9363896 68.4636104
# Within SD:      9.166782  8.0509046 10.4373219
# Between SD:     8.585948  8.3239359  8.8562078
# Omega-squared:  0.467317  0.2284142  0.8480383

statpsych documentation built on Sept. 11, 2024, 7:42 p.m.