Chapter 7

Question 1

When do you use a z test?

Answer 1

When the population parameters are known

Question 2

How are z tests and t tests similar?

Answer 2

Both are a probability distribution

Question 3

What does the sampling distribution look like for a t test?

Answer 3

Symmetrical

Question 4

True or false: t tests are affect by sample size?

Answer 4

True

Question 5

What does a one sample t test do?

Answer 5

Compare a single sample mean with the population mean

Question 6

What does a two sample t test do?

Answer 6

Compare two sample to one another

Question 7

What are the two types of two sample t tests?

Answer 7

Independent/between and repeated/within

Question 8

Example of independent measures?

Answer 8

People with and without pets, measure their stress level

Question 9

Example of independent measures?

Answer 9

Collecting data before and after people try a weight loss diet

Question 10

How do you find the population means with independent samples?

Answer 10

estimate by taking two samples

Question 11

What distribution is created for an independent sample

Answer 11

A sample distribution of mean differences

Question 12

What are other names for repeated measures t tests?

Answer 12

Paired t test, within subjects, matched, or dependent samples

Question 13

What does a repeated measures t test do?

Answer 13

Measures the same sample over time

Question 14

What does independent measures require?

Answer 14

Homogeneity of variance

Question 15

What is the df for independent measures?

Answer 15

df = n1 + n2 -2

Question 16

What is the df for repeated measures?

Answer 16

df = n-1

Question 17

When are findings significant?

Answer 17

When the null hypothesis is rejected?

Question 18

What does statistical significance say?

Answer 18

Whether the observed effect is likely to be due to chance only

Question 19

What does statistical significance not tell us?

Answer 19

The magnitude of the effect

Question 20

What is a criticism of hypothesis testing?

Answer 20

Results are sample size dependent

Question 21

What is effect size?

Answer 21

The magnitude or size of an effect

Question 22

What is raw metric?

Answer 22

Reports the effect size as the difference between the means

Question 23

Standardized mean differences

Answer 23

Uses Cohen’s d and represents the SD unit differences between groups

Question 24

What is percentage explained?

Answer 24

Uses R^2 and represents the proportion of variance that can be explained by the IV

Question 25

What does Cohen’s d do?

Answer 25

it was developed to encourage the reporting of effect size over p values

Question 26

How do you calculate sample mean from effect size?

Answer 26

xt = u + (dxo)

Question 27

What type of process is hypothesis testing?

Answer 27

Inferential

Question 28

What error is Type I?

Answer 28

when you reject the null but it is actually true

Question 29

What error is Type II?

Answer 29

Failing to reject the null when you can