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Chapters 1112

ANOVA Review. Compare 2 mean scores One way (1 factor or IV)Repeated measures (multiple factors)Main effectsInteractions F-ratioP-valuePost hoc tests and correctionsWithin and between. Multiple Factor ANOVA. aka Factorial ANOVA; incorporates more than one IV (factor). Only one DVFactor =

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Chapters 1112

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    1. Chapters 11&12 Factorial and Mixed Factor ANOVA and ANCOVA

    2. ANOVA Review Compare 2+ mean scores One way (1 factor or IV) Repeated measures (multiple factors) Main effects Interactions F-ratio P-value Post hoc tests and corrections Within and between

    3. Multiple Factor ANOVA aka Factorial ANOVA; incorporates more than one IV (factor). Only one DV Factor = IV Levels are the “groups” within each factor. In the reaction time example, there was one factor (“drug”) with three levels (beta blocker, caffeine, and placebo). Mixed factor is both within and between in the same analysis.

    4. Factorial ANOVA Example Studies are explained by their levels 2 x 3 or 3 x 3 x 4 The effect of three conditions of muscle glycogen at two different exercise intensities on blood lactate. There are 2 IV (factors: glycogen and exercise intensity) and 1 DV (blood lactate). 3 levels of muscle glycogen: depleted, loaded, normal. 2 levels of exercise intensity: 40% and 70% VO2max. 2 x 3 ANOVA, two-way ANOVA. 60 subjects randomized to the 6 cells (n = 10 per cell). Between subjects.

    5. Factorial ANOVA Example Each subject, after appropriate glycogen manipulation, performs 30 minute cycle ergometer ride at either low intensity (40%) or high intensity (70%). Blood is sampled following ride for lactate level.

    6. 3 F ratios in 2-way ANOVA 2 “Main Effects” – a ‘main effect” looks at the effect of one IV while ignoring the other IV(s), i.e., “collapsed across” the other IV(s). Based on the “marginal means” (collapsed). Main effect for Intensity – based on “row” marginal means (collapsed across glycogen state). If significant, look at mean values to see which one is larger (since there are only 2 means).

    7. 3 F ratios in 2-way ANOVA Main effect for glycogen state Compare column marginal means. If significant, perform follow-up procedures on the 3 means (collapsed across intensity). Main effects are easily followed up if the “interaction” (see below) is not significant. Each main effect is treated as a single factor ANOVA while ignoring the other factor. If the interaction is significant, focus on the interaction even if the main effects are significant. Ignore the main effects

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