Use the preparation materials to prepare hand-written answers for the following questions. Please ask any questions on the "Questions -- Preparation Guide" on the course Team (see link on the homepage).
- Thoroughly compare and contrast a (generic) simple and full models. You should have at least five characteristics that you discuss.
- Define Yij, Ȳi., Ȳ.., ni, n, εij.
- What is the simple model in a 2-sample t-test. Express this in symbols, in words, and graphically.
- What is the full model in a 2-sample t-test. Express this both in symbols, in words, and graphically.
- What is SSTotal? Express this as a formula and in words with respect to residuals from a model (be specific about which model), as a measure of lack-of-fit, and graphically.
- What is SSwithin? Express this as a formula and in words with respect to residuals from a model (be specific about which model), as a measure of lack-of-fit, and graphically.
- Show how SSTotal partitions into two components.
- What is SSAmong? Express this as a formula and in words with respect to comparing two models (be specific about models), as it relates to lack-of-fit, and graphically.
- Explain how SSAmong changes as the difference in group means is increased.
- Explain how SSAmong changes relative to SSWithin as the difference in group means is increased.
- Is SSAmong a measure of “signal” or “noise”? A measure of “benefit” or “cost” (of using the full model)?
- What does dfAmong measure? Express this in relation to two models.
- How do you convert any SS to a “true variance”?
- MSTotal and MSWithin measure the variability of what “entities”?
- How do MSTotal and MSWithin differ?
- MSAmong measures the variability of what “entities”?
- How is an F test statistic computed?
- What does a “large” F test statistic mean? Answer this in terms of “signal” and “noise”, variability explained and unexplained (be specific about what is “explaining”), simple and full models, and null and alternative hypotheses.
- What does a “small” p-value (computed from an F test statistic) mean? Answer this in terms of “signal” and “noise”, variability explained and unexplained (be specific about what is “explaining”), simple and full models, and null and alternative hypotheses.
- [Optional] What questions do you have from this reading that you would like me to address? [Please be as specific as possible. Don't just say "everything" or "I don't understand anything." Of course, you can ask me questions about the reading before class on MS Teams.]