Term
Describe a repeated measures (aka within subjects or within groups) design. |
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Definition
all individuals participate in all of the different treatment conditions; single factor
2 treatment levels and 1 factor |
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Term
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Definition
Ho: μ1 = μ2 = μ3... Hi: at least one μ is different |
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Term
what are the sources of variability in the repeated measures ANOVA? |
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Definition
Between Groups Variance Due to 1. Treatment Effect 2. Chance • Individual Differences • Experimental Error Within Groups Variance Due to 1. Just Chance • Individual Differences • Experimental Error |
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Term
What advantages are there to running repeated measures research design? |
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Definition
- eliminates individual differences - reduced variability = reduced error and more power |
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Term
What source of variance is removed from the error term in an extra calculation step in the RM ANOVA? |
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Definition
We eliminate treatment effects from the denominator of the F ratio exactly as we did for the independent measures ANOVA; we use the variance that exists within treatments. |
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Term
Why are there no individual differences in the between groups variance? |
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Definition
We measure the individual differences and then subtract them from the rest of the variability. The variance that remains is pure error without any systematic differences that can be explained by treatment effects or by individual differences. |
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Term
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Definition
scores in each treatment level |
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Term
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Definition
number of treatment conditions |
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Term
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Definition
number of scores in each level |
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Term
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Definition
total number of scores in the entire experiment |
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Term
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Definition
sum of all the scores (X) in each treatment level |
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Term
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Definition
sum of all scores in study (T) |
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Term
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Definition
Person total (allows us to subtract individual differences in denominator of F test) |
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Term
Post hoc tests for a RM ANOVA |
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Definition
Tukey's HSD and the Scheffe test can be used in the exact same manner as was done for the independent measures ANOVA, provided that you substitute MSerror in place of MSwithintreatments in the formulas and use dferror in place of dfwithintreatments when locating the critical value in the statistical table. |
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Term
What are the basic assumptions for the RM ANOVA? |
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Definition
identical to those required by IM ANOVA: - the oberservations within each treatment must be independent - the population distribution within each treatment must be normal - the variances of the population distributions for each treatment should be equivalent |
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