Thinking Critically with Psychological Science

Question 1

range

Answer 1

the difference between the highest and lowest scores in a distribution

Question 2

control group

Answer 2

in an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment

Question 2

informed consent

Answer 2

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

Question 3

median

Answer 3

the middle score in a distribution; half the scores are above it and half are below it

Question 4

hindsight bias

Answer 4

the tendency to believe, after learning an outcome, that one would have foreseen it AKA: the I-knew-it-all-along phenomenon

Question 4

random assignment

Answer 4

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups

Question 5

random sample

Answer 5

a sample that fairly represents a population because each member has an equal chance of inclusion

Question 6

placebo effect

Answer 6

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent

Question 7

independent variable

Answer 7

the experimental factor that is manipulated; the variable whose effect is being studied

Question 8

correlation coefficient

Answer 8

a statistical index of the relationship between two things (from 1 to +1)

Question 8

critical thinking

Answer 8

thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions

Question 9

operational definition

Answer 9

a statement of the procedures (operations) used to define research variables Example: human intelligence may be operationally defined as “what an intelligence test measures.”

Question 10

theory

Answer 10

an explanation using an integrated set of principles that organizes observations and predicts behaviors or events

Question 11

debriefing

Answer 11

the postexperimental explanation of a study, including its purpose and any deceptions, to its participants

Question 11

naturalistic observation

Answer 11

observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

Question 12

confounding variable

Answer 12

a factor other than the independent variable that might produce an effect in an experiment

Question 13

normal curve

Answer 13

(normal distribution) a symmetrical, bell-shaped curve that describes the distribution of many types of data; most scores fall near the mean, or average (about 68 percent fall within one standard deviation of it) and fewer and fewer near the extremes

Question 14

scatterplot

Answer 14

a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation).

Question 15

standard deviation

Answer 15

a computed measure of how much scores vary around the mean score

Question 17

correlation

Answer 17

a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other

Question 19

double-blind procedure

Answer 19

an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies

Question 21

dependent variable

Answer 21

the outcome factor; the variable that may change in response to manipulations of the independent variable

Question 22

hypothesis

Answer 22

a testable prediction, often implied by a a testable prediction, often implied by a theory

Question 24

experimental group

Answer 24

in an experiment, the group that is exposed to the treatment, that is, to one version of the independent variable

Question 25

statistical significance

Answer 25

a statistical statement of how likely it is that an obtained result occurred by chance

Question 26

survey

Answer 26

a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group

Question 27

population

Answer 27

all the cases in a group being studied, from which samples may be drawn

Question 28

mode

Answer 28

the most frequently occurring score(s) in a distribution

Question 29

replication

Answer 29

repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

Question 30

experiment

Answer 30

a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant factors

Question 31

case study

Answer 31

an observation technique in which one person is studied in depth in the hope of revealing universal principles

Question 32

mean

Answer 32

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores