Chapter 1

Question 1

Descriptive statistic

Answer 1

organizes, summarizes, and communicates a group of numerical observations

Question 2

inferential statistic

Answer 2

uses sample data to make a general estimates about the larger population

Question 3

sample

Answer 3

is a set of observations drawn from the population of interest

Question 4

population

Answer 4

includes all possible observations about which we’d like to know something

Question 5

variable

Answer 5

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

Question 6

discrete observations

Answer 6

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

Question 7

continuous observation

Answer 7

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

Question 8

nominal variable

Answer 8

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

Question 9

ordinal variable

Answer 9

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

Question 10

interval variable

Answer 10

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 11

ratio variable

Answer 11

is a variable that meets the criteria for an interval variable but also has a meaningful zero point.

Question 12

scale variable

Answer 12

a variable that meets the criteria for an interval variable or a ratio variable

Question 13

level

Answer 13

is a discrete value or condition that a variable can take on

Question 14

independent variable

Answer 14

has at least two levels that we either manipulate or observe to determine its effects on teh dependent variable

Question 15

confounding variable

Answer 15

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 16

reliability

Answer 16

refers to the consistency of a measure

Question 17

validity

Answer 17

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

Question 18

hypothesis testing

Answer 18

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

Question 19

operational definition

Answer 19

specifies the operations or procedures used to measure or manipulate a variable

Question 20

correlation

Answer 20

is an association between two or more variables

Question 21

random assignment

Answer 21

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

Question 22

experiment

Answer 22

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

Question 23

between-groups research design

Answer 23

participants experience one, and only one, level of independent variable

Question 24

within-groups research design

Answer 24

the different levels of the independent variables are experienced by all participants in the study, also called repeated-measures design.

Question 25

outlier

Answer 25

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

Question 26

outlier analysis

Answer 26

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