Changes between Version 3 and Version 4 of SOPs/anova
- Timestamp:
- 05/24/13 14:09:14 (12 years ago)
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SOPs/anova
v3 v4 1 Note that ANOVA and post-hoc tests can be performed in Prism too. 2 1 3 == One-way ANOVA == 2 4 3 5 See the [http://www.graphpad.com/support/faqid/1745/ Prism help page] for some general considerations. 4 5 Note that ANOVA and post-hoc tests can be performed in Prism too.6 7 6 8 7 ==== Reading in Data ==== … … 66 65 == Two-way ANOVA == 67 66 68 Two-way ANOVA should be used for experiments where t o different factors are being varied (such as comparing different treatments of different genotypes of mice).67 Two-way ANOVA should be used for experiments where two different factors are being studied (such as comparing different treatments of different genotypes of mice). 69 68 70 69 ==== Reading in Data ==== … … 85 84 ==== Creating an ANOVA Table ==== 86 85 * Use the command //anova// or //aov// with summary. The first argument is the dependent variable, followed by ~, and then by independent variable(s). 87 * So if we want to set up a model where weight is a function of the group (e.g., the weight potentially depends on the group)86 * So if we want to set up a model where weight is a function of the group and/or the genotype, with a potential interaction (e.g., the difference between groups depends on the genotype), the typical analysis would look like 88 87 89 88 {{{ … … 97 96 }}} 98 97 98 Note that the p-value for each factor depends on the order of the factors in the above formulas. 99 99 100 == Post-Test: Comparing All Pairs of Means == 101 102 As before, with 1-way ANOVA, 103 {{{ 104 TukeyHSD( aov (weight ~ group * genotype, data=strains) ) 105 }}} 106 107 If the experimental design is unbalanced (e.g., some groups are more replicated than others), we need a more complex model. 108
