Chapter 2

Question 1

empiricism

Answer 1

the belief that accurate knowledge can be acquired through observation

Question 2

scientific method

Answer 2

a procedure for using empirical evidence to establish facts

Question 3

theories

Answer 3

hypothetical explanations of natural phenomena

Question 4

hypothesis

Answer 4

falsifiable prediction made by a theory

Question 5

empirical method

Answer 5

a set of rules and techniques for observation

Question 6

operational definition

Answer 6

description of a property in measurable terms

Question 7

construct validity

Answer 7

the extent to which a videocamera aimed at a face adequately characterizes the property (property of an operational definition)

Question 8

power

Answer 8

a detector’s ability to detect the presence of differences or changes in the magnitude of a property

Question 9

reliability

Answer 9

a detector’s ability to detect the absence of differences or changes in the magnitude of a property

Question 10

demand characteristics

Answer 10

those aspects of an observational setting that cause people to behave as they think someone else wants or expects

Question 11

naturalistic observation

Answer 11

a technique for gathering scientific information by unobtrusively observing people in their natural environments

Question 12

observer bias

Answer 12

tendency for observers’ expectations to influence both what they believe they observed and what they actually observed

Question 13

double-blind study

Answer 13

a study in which neither the researcher nor the participant knows how the participants are expected to behave

Question 14

population

Answer 14

complete collection of people (eg. population of Canada, population of human beings)

Question 15

sample

Answer 15

a partial collection of people/animals/things drawn from a population

Question 16

frequency distribution

Answer 16

a graphic representation showing the number of times in which the measurement of a property takes on each of its possible values

Question 17

normal distribution

Answer 17

a mathematically defined distribution in which the frequency of measurements is highest in the middle and decreases symmetrically in both directions (Gaussian)

Question 18

mode

Answer 18

the value of the most frequently observed measurement

Question 19

mean

Answer 19

the average value of all the measurements

Question 20

median

Answer 20

value that is in the middle

Question 21

range

Answer 21

value of the largest measurement in a frequency minus the value of the smallest measurement

Question 22

standard deviation

Answer 22

how each of the measurements in a frequency distribution differs from the mean

Question 23

variable

Answer 23

properties that can take on different values

Question 24

correlation

Answer 24

variations in the value of one variable are synchronized with variations in the value of the other

Question 25

correlation coefficient

Answer 25

mathematical measure of both the direction and strength of correlation (r)

Question 26

natural correlation

Answer 26

the correlations we observe in the world around us

Question 27

third-variable problem

Answer 27

the natural correlation between two variables cannot be taken as evidence of a causal relationship between them because a third variable might be causing them both

Question 28

experimentation

Answer 28

a technique for establishing the causal relationship between variables

Question 29

manipulation

Answer 29

technique for determining the causal power of a variable by actively changing its value

Question 30

independent variable

Answer 30

the variable that is manipulated in an experiment

Question 31

dependent variable

Answer 31

variable that is measured in an experiment

Question 32

self-selection

Answer 32

a problem that occurs when anything about a participant determines the participant’s condition

Question 33

random assignment

Answer 33

a procedure that assigns participants to a condition by chance

Question 34

internal validity

Answer 34

an attribute of an experiment that allows it to establish causal relationships

Question 35

external validity

Answer 35

an attribute of an experiment in which variables have been operationally defined in a normal, typical, or realistic way

Question 36

case method

Answer 36

a procedure for gathering scientific information by studying a single individual

Question 37

random sampling

Answer 37

a technique for selecting participants that ensures that every member of a population has an equal chance of being included in the sample

Question 38

replication

Answer 38

an experiment that uses the same procedures as a previous experiment but with a new sample form the same population

Question 39

type I error

Answer 39

when researchers conclude that there is a relationship between two variables when in fact there is not

Question 40

type II error

Answer 40

when researchers conclude that there is not a relationship between two variables when in fact there is

Question 41

informed consent

Answer 41

a verbal agreement to participate in a study made by an adult who has been informed of all the risks that participation may entail

Question 42

debriefing

Answer 42

verbal description of the true nature and purpose of a study