Chapter 9 - Evaluating Hypotheses

Question 1

What are descriptive statistics?

Answer 1

The science of describing distributions of samples of populations.

Question 2

What are inferential statistics?

Answer 2

The science of using sample statistics to make inferences or decisions about population parameters.

Question 3

What is a hypothesis?

Answer 3

An assumption or inference about a parameter or distribution that can be tested.

Question 4

What is a null hypothesis?

Answer 4

The hypothesis that there is no effect or no difference.

Question 5

What is an alternative hypothesis?

Answer 5

The hypothesis that there is in fact an effect or a difference.

Question 6

What are the symbols for null hypothesis?

Answer 6

Ho (small o)

Question 7

What are the symbols for alternative hypothesis?

Answer 7

H1 (small 1)

Question 8

What is a test statistic?

Answer 8

A statistic specifically designed to facilitate the making of inferences.

Question 9

What is a directional (one-tailed) alternative hypothesis?

Answer 9

Where one direction of change (an increase or a decrease based on prior empirical research) is specified in advance.

Question 10

What is a non-directional (two-tailed) alternative hypothesis?

Answer 10

Where the hypothesized change can be either an increase or a decrease.

Question 11

What is a Type 1 error?

Answer 11

Rejecting the null hypothesis when it is in fact true.

Question 12

What is a Type 2 error?

Answer 12

Failing to reject the null hypothesis when it is in fact false.

Question 13

What is the level of significance?

Answer 13

The probability (signified by Greek a) of making a Type 1 error.

Question 14

What does the Greek ‘a’ signify?

Answer 14

The probability of making a Type 1 error (also called “the level of significance”)

Question 15

What is statistically significant?

Answer 15

Leading to the rejection of the null hypothesis.

Question 16

What is power?

Answer 16

The probability of rejecting the null hypothesis when the null hypothesis is in fact false.

Question 17

What does the Greek ‘B’ signify?

Answer 17

The probability of making a Type II error.

Question 18

What is practical significance?

Answer 18

The degree to which a result is important. Measures whether the result is important.

Question 19

What is effect size?

Answer 19

A measure of the magnitude of a result.

Question 20

What is statistical significance?

Answer 20

Ensures that the result is not merely a chance fluctuation.

Question 21

What is the general formula for the test statistic?

Answer 21

sample statistic minus population parameter divided by the standard error of the sample statistic.

Question 22

What is a sample statistic?

Answer 22

The statistic that point-estimates the parameter of interest.

Question 23

What is the observed value of the test statistic?

Answer 23

The value of a test statistic computed from the sample.

Question 24

What is the procedure for hypothesis evaluation?

Answer 24

1. State the null and alternative hypothesis.
2. Set the criterion for rejecting Ho (null hypothesis).
3. Collect a sample and compute the observed values of the sample statistic and the test statistic.
4. Interpret the results.

Question 25

Sample statistic

Answer 25

A number that can be calculated from sample data.

Question 26

Population parameter

Answer 26

A number describing a population.