Inferential statistics

Question 1

Probability

Answer 1

Probability is used to predict the type of samples that are likely to be obtained from a population. Thus, probability establishes a connection between samples and populations

Question 2

Sampling distribution of means

Answer 2

A frequency distribution showing all possible sample means that occur when samples of a particular size are drawn from a population

Question 3

Central limit theorem

Answer 3

A statistical principle that defines the mean, standard deviation, and shape of a sampling distribution

Question 4

Standard error of the mean

Answer 4

The standard deviation of the sampling distribution of means

Question 5

Representative sample

Answer 5

A sample in which the individuals and scores accurately reflect the individuals and scores in the population

Question 6

Sampling error

Answer 6

When random chance produces an unrepresentative sample from a population, with the result that the sample’s statistic is different from the population parameter it represents

Question 7

Region of rejection

Answer 7

The part of a sampling distribution containing means that are so unlikely that we reject that they represent the underlying raw score population

Question 8

Criterion

Answer 8

The probability that defines whether a sample is unlikely to represent the underlying raw score population

Question 9

Critical value

Answer 9

The score that marks the inner edge of the region of rejection in a sampling distribution; values that fall beyond it lie in the region of rejection

Question 10

Inferential statistics

Answer 10

Procedures for deciding whether sample data represent a particular relationship in the population

Question 11

Parametric statistics

Answer 11

Inferential procedures that require certain assumptions about the raw score population represented by the sample; used when we compute the mean

Question 12

Nonparametric statistics

Answer 12

Inferential procedures that do not require stringent assumptions about the raw score population represented by the sample; used with the median and mode

Question 13

Experimental hypotheses

Answer 13

Two statements describing the predicted relationship that may or may not be demonstrated by a study

Question 14

Two-tailed test

Answer 14

The type of inferential test used when we do not predict whether dependent scores will increase or decrease

Question 15

One-tailed test

Answer 15

The type of inferential test used when we predict that dependent scores will only increase or will only decrease

Question 16

Statistical hypothesis

Answer 16

Statements that describe the population parameters the sample statistics represent if the predicted relationship exists or does not exist

Question 17

Alternative hypothesis

Answer 17

The hypothesis describing the population parameters the sample data represent if the predicted relationship does exist in nature

Question 18

Null hypothesis

Answer 18

The hypothesis describing the

population parameters the sample data represent if the predicted relationship does not exist in nature

Question 19

z-test

Answer 19

The parametric procedure used in a single-sample experiment when the standard deviation of the raw score population is known

Question 20

Alpha (a)

Answer 20

The Greek letter that symbolizes the criterion probability

Question 21

Significant

Answer 21

Describes results that are unlikely to result from sampling error when the predicted relationship does not exist; it indicates rejection of the null hypothesis

Question 22

Nonsignificant

Answer 22

Describes results that are likely to result from sampling error when the predicted relationship does not exist; it indicates failure to reject the null hypothesis

Question 23

Type 1 error

Answer 23

Rejecting the null hypothesis when it is true (that is, saying the independent variable works when it does not)

Question 24

Type 2 error

Answer 24

Retaining the null hypothesis when it is false (that is, failing to identify that the independent variable does work as predicted)

Question 25

Power

Answer 25

The probability that we will detect a relationship and correctly reject a false null hypothesis; the probability of avoiding a Type II error

Question 26

Cohen’s d

Answer 26

d = Sample mean difference / Sample standard deviation