Chapter 6 - Methodological Control in Experimental Research

Question 1

Between-Subject Designs

Answer 1

An experimental design in which different groups of participants serve in the different conditions of the study.

Question 2

Equivalent Groups

Answer 2

Groups of participants in a between‐subjects design that are essentially equal in all ways except levels of the independent variable.

Question 3

Random Assignment

Answer 3

The most common procedure for creating equivalent groups in a between‐subjects design; each individual volunteering for the study has an equal probability of being assigned to any of the groups

Question 4

Blocked Random Assignment

Answer 4

A procedure used in between‐subjects designs to accomplish random assignment and ensure an equal number of participants in each condition; ensures that each condition of the study has a subject randomly assigned to it before any condition has a subject assigned to it again.

Question 5

Matching

Answer 5

A procedure for creating equivalent groups in which participants are measured on some factor (a “matching variable”) expected to correlate with the dependent variable; groups are then formed by randomly assigning to groups participants who score at the same level on the matching variable.

Question 6

Matching Variable

Answer 6

A variable selected for matching participants in a matched groups study.

Question 7

Within Subject Design

Answer 7

An experimental design in which the same participants serve in each of the conditions of the study; also called a repeated‐measures design.

Question 8

Order Effect

Answer 8

Can occur in a within‐subjects design when the experience of participating in one of the conditions of the study influences performance in subsequent conditions; see Progressive effect and Carryover effect.

Question 9

Progressive Effect

Answer 9

In a within‐subjects design, an order effect in which the accumulated effects are assumed to be the same from trial to trial (e.g., fatigue).

Question 10

Carryover Effect

Answer 10

Form of sequence effect in which systematic changes in performance occur as a result of completing one sequence of conditions rather than a different sequence.

Question 11

Counterbalancing

Answer 11

For a within‐subjects variable, any procedure designed to control for sequence effects.

Question 12

Complete Counterbalancing

Answer 12

Occurs when all possible orders of conditions are used in a within‐subjects design.

Question 13

Partial Counterbalancing

Answer 13

Occurs when a subset of all possible orders of conditions is used in a within‐subjects design (e.g., a random sample of the population of all possible orders could be selected).

Question 14

Latin Square

Answer 14

Form of partial counterbalancing in which each condition of the study occurs equally often in each sequential position and each condition precedes and follows each other condition exactly once.

Question 15

Reverse Counterbalancing

Answer 15

Occurs in a within‐subjects design when participants are tested more than once per condition; subjects experience one sequence and then a second with the order reversed from the first (e.g., A–B–C–C–B–A).

Question 16

Block Randomization

Answer 16

A procedure used in within‐subjects design as a counterbalancing procedure to ensure that when participants are tested in each condition more than once, they experience each condition once before experiencing any condition again.

Question 17

Error Bars

Answer 17

On bar or line graphs, they indicate the amount of variability around a mean; often reflect standard deviations or confidence intervals.

Question 18

Cross-Sectional Study

Answer 18

In developmental psychology, a design in which age is the independent variable and different groups of people are tested; each group is of a different age.

Question 19

Longitudinal Study

Answer 19

In developmental psychology, a design in which age is the independent variable and the same group of people is tested repeatedly at different ages.

Question 20

Cohort Sequential Designs

Answer 20

In developmental psychology research, a design that combines cross‐sectional and longitudinal designs; a new cohort is added to a study every few years and then studied periodically throughout the time course of the study.

Question 21

Experimenter Bias

Answer 21

Occurs when an experimenter’s expectations about a study affect its outcome.

Question 22

Protocols

Answer 22

A detailed description of the sequence of events in a research session; used by an experimenter to ensure uniformity of treatment of research participants.

Question 23

Double-Blind

Answer 23

A control procedure designed to reduce bias; neither the participant nor the person conducting the experimental session knows which condition of the study is being tested; often used in studies evaluating drug effects.

Question 24

Single Blind

Answer 24

A control procedure designed to reduce subject bias, in which the participant does not know which condition of the study is being tested (the experimenter, however, does know).

Question 25

Participant Bias

Answer 25

Can occur when the behavior of subjects is influenced by their beliefs about how they are supposed to behave in a study.

Question 26

Hawthorne Effect

Answer 26

A form of participant bias in which a participant’s behavior is influenced by the mere knowledge of being in an experiment and therefore important to the experimenter.

Question 27

Good Subject Role

Answer 27

A form of participant bias in which participants try to guess the experimenter’s hypothesis and then behave in such a way as to confirm it.

Question 28

Evaluation Apprehension

Answer 28

A form of anxiety experienced by participants that leads them to behave so as to be evaluated positively by the experimenter.

Question 29

Demand Characteristics

Answer 29

A feature of the experimental design or procedure that increases the chances that participants will detect the true purpose of the study.