14. Comparison among categories: ANOVA II

Question 1

what is the difference between ANOVA and regression?

Answer 1

both are linear models but

Regression has a continuous explanatory variable

ANOVA has a categorical explanatory variable

Question 2

what is two-way analysis of variance?

Answer 2

quantifies variation among groups due to sampling error

quantifies real variation among groups

quantifies variation due to interaction between groups

measures of variation are called mean squares

Question 3

What is ANCOVA?

Answer 3

Regression + ANOVA

one explanatory variable is categorical the other is continuous

Question 4

when doing a two-way ANOVA what do we expect if there is no interaction?

Answer 4

relationship is parallel

Question 5

when doing a two-way ANOVA what do we expect if there is an interaction?

Answer 5

there in an intercept

Question 6

What does a two-way ANOVA look like

Answer 6

y:
variation of factor A
variation of factor B
variation caused by interaction
error
total

x:
same as ANOVA