Test of Differences

Question 1

parametric data

Answer 1

• allow for eval of hypotheses for a particular population parameter
• continuous data
• normal distribution
• roughly equal variance btw groups

Question 2

non-parametric

Answer 2

• allow for eval of hypotheses for entire population distributions
• categorical or continuous data
• no assumptions –> non-normal distribution and unequal variance

Question 3

independent t-test

Answer 3

• parametric

- evaluates whether two means collected from two independent samples differ

Question 4

paired t-test

Answer 4

evaluates whether two means collected from the same samples differ or 2 paired observations

Question 5

ANOVA

Answer 5

• 3 or more independent groups differ

Question 6

repeated measures ANOVA

Answer 6

an ANOVA for data that has been measured repeatedly on the same subjects

Question 7

factorial ANOVA

Answer 7

used when a continuous outcome has been measured with mulitple factors to test significant effect of those factors

Question 8

mixed ANOVA

Answer 8

used when a continous outcome has been measured with multiple groups repeatedly over time

Question 9

analysis of covariance (ANCOVA)

Answer 9

• used when a continous outcome has been measured with a confounding variable for the purpose of adjusting the confounder
• control for other factors that might influence the outcome

Question 10

common used of an ANCOVA

Answer 10

• experimental designs, to control for factors which cannot be randomized but which can be measured on an interval scale
• observational designs, to remove the effects of variables which modify the relationship of the categorical independents to the interval dependent

Question 11

non-parametric data works on what

Answer 11

• the principle of ranking the data (ordinal)

- ranked from smallest to largest

Question 12

limitations to non-parametric tests

Answer 12

• hold less statistical power
• may not be directly testing null hypothesis of interest
• limited choices
• cannot be related to the confidence interval

Question 13

mann-whitney U test

Answer 13

• takes place of independent t-test

- two means from two independent samples differ

Question 14

Wilcoxen signed rank test

Answer 14

• like a paired t-test

- two means collected from same sample differ

Question 15

kruskal-walls H test

Answer 15

• like ANOVA

- test the mean difference btw independent groups

Question 16

friedman test

Answer 16

• like RM-ANOVA

- test the mean difference btw related groups