Two-Way Analysis of Variance

In statistics, analysis of variance (ANOVA) is a collection of statistical models used to distinguish between an observed variance in a particular variable and its component parts. In its simplest form, ANOVA provides a statistical test of whether or not the means of several groups are all equal, and therefore generalizes a test between these groups. One test often used by statisticians and researchers in their work is the Two-Way ANOVA, which determines the differences--and possible interactions--when variables are presented from the perspective of two or more categories. When a Two-Way ANOVA is implemented, it enables one to compare and contrast variables resulting from independent or joint actions. This brief provides guidance on how R can be used to facilitate Two-Way ANOVA for data analysis and graphical presentation. Along with instruction on the use of R and R syntax associated with Two-Way ANOVA, this brief will also reinforce the use of descriptive statistics and graphicalfigures to complement outcomes from parametric Two-Way ANOVA.

Includes supplementary material: sn.pub/extras

Autorentext

Thomas W. MacFarland

Senior Research Associate and Associate Professor

Nova Southeastern University Office of Institutional Effectiveness

Fort Lauderdale, FL 33314 tommac@nova.edu

Inhalt

1. Introduction.2. Data Import or Data Entry3. Data Organization4. Display the Code Book5. Conduct a Visual Data Check6. Descriptive Analysis of the Data.