One-way ANOVA

Question 1

Degrees of freedom for F test

Answer 1

• # of groups - 1 AND n - 1

Question 2

ANOVA F test

Answer 2

• one independent variable
• extension of two-sample t-test
• t^2 = F, but F allows to test more than 2 groups (more information)

Question 3

Hypotheses

Answer 3

• HA: atleast one mean differs
• Ha cannot assume direction.
• H0: all means are equal

Question 4

Assumptions

Answer 4

1. Normality
2. Constant variance: the largest SD cannot be more than 2x the smallest SD.
3. Independent samples drawn

Question 5

SS

Answer 5

Sum of squares: measure of dispersion/qunatifies the variability.

Question 6

MS

Answer 6

Mean sum of squares
- MS = SSE/n-m

Question 7

Family-wise alpha rate:

Answer 7

• probability of making one or more false discoveries or type 1 errors when performing multiple hypotheses tests.
• rate keeps increasing as we perform multiple comparisons => bonferroni/tukey methods help keep this strict. (5% for one test but almost 15% for 3 tests).

Question 8

Estimate of common standard deviation

Answer 8

• Sp = square root of MSE

Question 9

Errors

Answer 9

• type 1 error: assume there IS but actually there is NONE.
• type 2 error: assume there is NONE but actually there iS.