eta.F: Eta and Coefficient of Determination (R2) for ANOVA from F

In doomlab/MOTE: Effect Size and Confidence Interval Calculator

Eta and Coefficient of Determination (R2) for ANOVA from F

Description

This function displays eta squared from ANOVA analyses and their non-central confidence interval based on the F distribution. These values are calculated directly from F statistics and can be used for between subjects and repeated measures designs. Remember if you have two or more IVs, these values are partial eta squared.

Usage

eta.F(dfm, dfe, Fvalue, a = 0.05)

Arguments

dfm	degrees of freedom for the model/IV/between
dfe	degrees of freedom for the error/residual/within
Fvalue	F statistic
a	significance level

Details

Eta is calculated by multiplying the degrees of freedom of the model by the F-statistic. This is divided by the product of degrees of freedom of the model, the F-statistic, and the degrees of freedom for the error or residual.

eta^2 = (dfm * Fvalue) / (dfm * Fvalue + dfe)

Learn more on our example page.

Value

Provides eta with associated confidence intervals and relevant statistics.

eta	effect size
etalow	lower level confidence interval of eta
etahigh	upper level confidence interval of eta
dfm	degrees of freedom for the model/IV/between
dfe	degrees of freedom for the error/resisual/within
F	F-statistic
p	p-value
estimate	the eta squared statistic and confidence interval in APA style for markdown printing
statistic	the F-statistic in APA style for markdown printing

Examples

#The following example is derived from the "bn1_data" dataset, included
#in the MOTE library.

#A health psychologist recorded the number of close inter-personal
#attachments of 45-year-olds who were in excellent, fair, or poor
#health. People in the Excellent Health group had 4, 3, 2, and 3
#close attachments; people in the Fair Health group had 3, 5,
#and 8 close attachments; and people in the Poor Health group
#had 3, 1, 0, and 2 close attachments.

anova_model = lm(formula = friends ~ group, data = bn1_data)
summary.aov(anova_model)

eta.F(dfm = 2, dfe = 8,
      Fvalue = 5.134, a = .05)

doomlab/MOTE documentation built on April 17, 2022, 2:08 a.m.