Statistic Quizzes

quiz_8.docx

Question 1

· If the overall F is statistically significant, at least one pair of means must also be statistically significant.   Answer

True

False

Question 2

·   F can never be negative.   Answer

True

False

Question 3

·   One drawback of ANOVA is that it allows type 1 error to escalate for every additional group tested.   Answer

True

False 

Question 4

·   If a study has 3 groups of 25 subjects each, the degrees of freedom are 2 and 24.   Answer

True

False

Question 5

·   All F values are positive.   Answer

True

False

Question 6

  In ANOVA, where should you look for the treatment effect?   Answer

. In the within-group variance.

· In the between-group variance.

· In the total variance.

· Within a single individual's score.

Question 7

·   When and why would you conduct post hoc tests as a follow up to the overall F test?   Answer

	· a.	When the overall F test is NOT significant; to determine which of the pairs of groups may be significant.
	· b.	When the overall F test is NOT significant; to determine why the overall F test is not significant.
·	· c.	· When the overall F test is significant; to determine between which pairs of groups the significant difference lies.
·	· d.	When the overall F test IS significant; to determine if the significance is only the result of chance.

·  Question 8

·   We use an F test rather than a t test for multi-group studies primarily to    Answer

·	· a.	· Avoid calculating standard deviations from the variances.
·	· b.	· Be able to use a single formula regardless of differing sample sizes between groups.
·	· c.	· Reduce calculation time.
·	· d.	· Avoid escalating type 1 error rates.

Question 9

·   The appropriate statistic to use when testing the hypothesis for a study with three treatment groups is a   Answer

Question 10

·   When the null hypothesis is true, the calculated F should be close to    Answer

·	· a.	· 0.
·	· b.	· 1.
·	· c.	· Infinity.
·	· d.	· There is not enough information to tell.