Chapter X

Question 1

Attrition

Answer 1

the loss of participants in the course of a study when they fail to complete it.

Question 2

Ceiling Effect

Answer 2

the effect that occurs when scores on a dependent variable bunch up at the maximum score level; compare floor effect.

Question 3

Complete Replication

Answer 3

replication that includes all the conditions of the original study.

Question 4

Conceptual Replication

Answer 4

replication that examines the same question investigated in the original study but operationalizes the constructs differently.

Question 5

Construct Validity

Answer 5

the degree to which the constructs (the
conceptual variables) that researchers claim to be studying are, in fact, the constructs that they are manipulating and measuring.

Question 6

Debriefing

Answer 6

a conversation with a participant, after data are gathered from that participant, in which the researcher conveys additional information about the study.

Question 7

Demand Characteristics

Answer 7

cues that influence participants’ beliefs about the hypothesis being tested and the behaviors expected of them.

Question 8

Differential attrition

Answer 8

significantly different rates of or reasons for participants’ discontinuing a study across the various condi- tions in that study.

Question 9

Direct Replication

Answer 9

replication in which the researchers follow the procedures used in the original study as closely as possible.

Question 10

Double-Blind Procedure

Answer 10

in experiments, a procedure in which neither the participants nor the experimenters are aware of who is receiving the actual treatment and who is receiving a placebo.

Question 11

Experimenter expectancy effects

Answer 11

unintentional ways in which researchers influence their participants to respond in a manner consistent with the researchers’ hypothesis.

Question 12

External validity

Answer 12

the generalizability of the findings beyond the circumstances of the present study.

Question 13

Floor effect

Answer 13

an effect that occurs when scores on a dependent variable bunch up at the minimum score level; compare ceiling effect

Question 14

History

Answer 14

events that occur while a study is being conducted and that are not a part of the experi- mental manipulation or treatment.

Question 15

Instrumentation

Answer 15

changes that occur in a measuring instrument during the course of data collection (e.g., pretest to posttest changes in the observer’s criteria for rating depression).

Question 16

Internal Validity

Answer 16

the degree to which we can be confident that a study demonstrated that one variable had a causal effect on another variable.

Question 17

Manipulation check

Answer 17

an approach that seeks to improve the validity of an experiment by determining whether the procedures used to manipulate an independent variable successfully captured the intended construct.

Question 18

Masking (blinding)

Answer 18

a procedure in which the par- ties involved in an experiment are kept unaware of the hypothesis being tested and/or the condition to which each participant has been assigned.

Question 19

Maturation

Answer 19

the ways in which people naturally change over time, independent of their participation in a study.

Question 20

Partial Replication

Answer 20

replication that includes only some of the conditions of the original study.

Question 21

Pilot Study

Answer 21

a trial run, usually conducted with a smaller number of participants, prior to initiating the actual experiment.

Question 22

Placebo Control Group

Answer 22

the group of participants in an experiment who do not receive the core treatment but are led to believe that they are (or may be) receiving it.

Question 23

Placebo Effect

Answer 23

the effect that occurs when participants’ expectations about how a treatment will affect them influence their responses (on the dependent variable) to that treatment.

Question 24

Quasi-Experiment

Answer 24

a study that has some features of an experiment but lacks key aspects of experimental control.

Question 25

Randomized Control Trial

Answer 25

an experiment in which participants are randomly assigned to different conditions for the purpose of examining the effectiveness of an intervention.

Question 26

Regression to the mean

Answer 26

the statistical concept that when two variables are not perfectly correlated (e.g., scores on a pretest and posttest), more extreme scores on one variable will be as- sociated overall with less extreme scores on the other variable. In experimental design, regression to the mean refers to the fact that when a group is selected because of their above- or below-average scores on a measure, the group’s average scoreon a retest (or on another related measure) will tend to regress toward (i.e., become closer to) the mean score of the overall population.

Question 27

Replication

Answer 27

the process of repeating a study to determine whether the original findings will be upheld.

Question 28

Replication and extension

Answer 28

a replication that adds a new design element to the original study.

Question 29

Selection

Answer 29

a potential threat to internal validity in which, at the start of a study, participants in the various conditions already differ on a characteristic that can partly or fully account for the eventual results.

Question 30

Sensitivity

Answer 30

the ability of a measure to detect an effect that actually is present.

Question 31

Statistical conclusion validity

Answer 31

the degree to which the statisti- cal treatment of data is proper and the researchers’ statistical conclusions are sound.

Question 32

Testing

Answer 32

a potential threat to internal validity in which the act of measuring participants’ responses affects how they respond on subsequent measures.

Question 33

Ecological Validity

Answer 33

the degree to which responses obtained in a research context generalize to behavior in natural settings; also refers to how well a research setting (e.g., tasks, procedures) corresponds to what people encounter in daily life.