Chapter One

Question 1

What is a Descriptive Statistic?

Answer 1

A descriptive statistic organizes, summarizes, and

communicates a group of numerical observations.

Question 2

What is an Inferential Statistic?

Answer 2

An inferential statistic uses sample data to make general

estimates about the larger population.

Question 3

What is a Sample?

Answer 3

A sample is a set of observations drawn from the

population of interest.

Question 4

What is a population?

Answer 4

The population includes all possible observations about

which we’d like to know something.

Question 5

What is the difference between Descriptive Statistics and Inferential Statistics?

Answer 5

Descriptive Statistics summarize numerical information about a sample.
Inferential Statistics draw conclusions about the broader population based on numerical information from a sample.

Question 6

What is a Variable?

Answer 6

A variable is any observation of a physical, attitudinal, or behavioral characteristic that can take on different values.

Question 7

What is a Discrete Observation?

Answer 7

A discrete observation can take on only specific values (e.g., whole numbers); no other values can exist between these numbers.

Question 8

What is a Continuous Observation?

Answer 8

A continuous observation can take on a full range of values (e.g., numbers out to several decimal places); an infinite number of potential values exists.

Question 9

What is a nominal variable?

Answer 9

A nominal variable is a variable used for observations that have categories, or names, as their values.

Question 10

What is an ordinal variable?

Answer 10

An ordinal variable is a variable used for observations that have rankings (i.e., 1st, 2nd, 3rd . . .) as their values.

Question 11

What is an Interval Variable?

Answer 11

An Interval Variable is a variable used for observations that have numbers as their values; the distance (or interval) between pairs of consecutive numbers is assumed to be equal.

Question 12

What is a Ratio Variable?

Answer 12

A Ratio Variable is a variable that meets the criterion for an interval variable but also has a meaningful zero point.

Question 13

What are the three main types of Variables?

Answer 13

The three main types of variables are nominal (or categorical), ordinal (or ranked), and scale. The third type A scale variable is a variable that meets the criteria for an interval variable or a ratio variable

Question 14

What is a Scale Variable?

Answer 14

A Scale Variable is a variable that meets the criteria for an interval variable or a ratio variable.

Question 15

What is a Level?

Answer 15

A Level is a discrete value or condition that a variable can take on.

Question 16

What is an Independent Variable?

Answer 16

An Independent Variable has at least two levels that we either manipulate or observe to determine its effects on the Dependent Variable.

Question 17

What is a Dependent Variable?

Answer 17

A dependent variable is the outcome variable that we hypothesize to be related to or caused by changes in the independent variable.

Question 18

What is a Confounding Variable?

Answer 18

A Confounding Variable is any variable that systematically varies with the independent variable so that we cannot logically determine which variable is at work; also called a Confound

Question 19

Why do we conduct Research?

Answer 19

We conduct research to see if the independent variable predicts the dependent variable.

Question 20

What does Reliability refer to?

Answer 20

Reliability refers to the consistency of a measure.

Question 21

What does Validity refer to?

Answer 21

Validity refers to the extent to which a test actually measures what it was intended to measure.

Question 22

What are the properties of a Good Measure?

Answer 22

A Good Measure is both Reliable and Valid.

Question 23

What is Hypothesis Testing?

Answer 23

Hypothesis Testing is the process of drawing conclusions about whether a particular relation between variables is supported by the evidence.

Question 24

What is operationalize or an operational definition?

Answer 24

An operational definition specifies the operations or procedures used to measure or manipulate a variable.

Question 25

What is a Correlation

Answer 25

A correlation is an association between two or more variables.

Question 26

How does Random Assignment work?

Answer 26

In random assignment every participant in a study has an equal chance of being assigned to any of the groups, or experimental conditions, in the study.

Question 27

What is an Experiment?

Answer 27

An experiment is a study in which participants are randomly assigned to a condition or level of one or more independent variables.

Question 28

What is the difference between a Correlational Study and an Experiment?

Answer 28

When possible, researchers prefer to use an experiment rather than a correlational study. Experiments use random assignment, which is the only way to determine whether one variable causes another.

Question 29

How does a Between-Groups research design work?

Answer 29

In a between-groups research design, participants experience one and only one level of the independent variable.

Question 30

How does a Within-Groups research design work?

Answer 30

In a within-groups research design all participants in the study experience the different levels of the independent variable; also called a repeated-measures design.

Question 31

What is an outlier?

Answer 31

An outlier is an extreme score that is either very high or very low in comparison with the rest of the scores in the sample.

Question 32

What is outlier analysis?

Answer 32

In outlier analysis, studies examine observations that do not fit the overall pattern of the data in an effort to understand the factors that influence the dependent variable.