An introduction to Two Way ANOVA (Factorial) also known as Factorial Analysis. Step by step visual instructions organize data to conduct a two way ANOVA. Includes a comparison with One Way ANOVA. Instructions on how to build a mean table. Playlist on Two Way ANOVA http://www.youtube.com/playlist?list=PLWtoq-EhUJe2TjJYfZUQtuq7a0dQCnOWp Like us on: http://www.facebook.com/PartyMoreStudyLess David Longstreet Professor of the Universe Professor of the Universe: David Longstreet http://www.linkedin.com/in/davidlongstreet/ MyBookSucks.Com
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0:05 - Setting Up Data 5:03 - Repeated Measures ANOVA 24:50 - Mixed Factorial Anova
I perform and interpret a two way ANOVA in SPSS. The example consists of 2 between subjects factors: one with 2 levels and one with 3 levels. So, it's a 2 * 3 between subjects design. I test both main effects and the interaction effect. I then follow-up with some basic post-hoc tests. I point out that the proper way to test the simple main effects for the interaction can only be achieved by adding a term to the syntax, as it can not be done through the menus. Also, this example is based on unbalanced design. That is, the sample sizes are unequal. This has important implications for factorial anovas, as I demonstrate through comparisons between the means reported in the descriptives table versus the means reported in the 'estimated marginal means' table. The references I mention in the video are: Keselman, H. J. Games, P. A., & Rogan, J. C. (1979). Protecting the overall rate of Type I errors for pairwise comparisons with an omnibus test statistic. Psychological Bulletin, 6(4), 884-888. Keppel, G. (1982). Design and analysis: A researcher's handbook. New Jersey: Prentice Hall. Howell, D. C. & McConaughy, S. H. (1982). Nonorthogonal analysis of variance: Putting the question before the answer. Educational and Psychological Measurement, 42, 9-24.
This video demonstrates how to conduct a two-way ANOVA in SPSS. Concepts such as main effects, interaction effects, post hoc tests, pairwise comparisons, Levene’s test, effect size, and statistical significance are described.
A tutorial on conducting a 2x2 Between Subjects Factorial ANOVA in SPSS/PASW.
A short video explaining main effects and interactions in factorial ANOVA experiments.
Reading the tables and graphs from a 2x2 factorial design - looking for interactions & main effects