Chapter 8 - Experimental Design

Question 0

Between-Subjects Design (also Independent Groups Design)

Answer 0

The between-subjects research design is an experiment in which different subjects are assigned to each group. It is also called an independent groups design.

Question 1

Attrition (also Mortality)

Answer 1

Attrition refers to the loss of subjects who decide to leave an experiment.

Question 2

Carryover Effect

Answer 2

The carry-over effect is a problem that may occur in repeated measures designs if the effects of one treatment are still present when the next treatment is given.

Question 3

Confounding Variable

Answer 3

A confounding variable is a variable that is not controlled in a research investigation. In an experiment, the experimental groups differ on both the independent variable and the confounding variable.

Question 4

Counterbalancing

Answer 4

Counterbalancing is a method of controlling for order effects in a repeated measures design by either including all orders of treatment presentation or randomly determining the order for each subject.

Question 5

Fatigue Effect

Answer 5

The fatigue effect is when someone scores poorly or doesn’t do as well as they possibly could have on the second part of a test or measurement because the first part tired them out.

Question 6

Independent Groups Design (Between-Subjects Design)

Answer 6

The independent groups design is an experiment design in which different subjects are assigned to each group. It is also called a between-subjects design.

Question 7

Internal Validity

Answer 7

Internal validity refers to the certainty with which results of an experiment can be attributed to the manipulation of the independent variable rather than to some other, confounding variable.

Question 8

Latin Square

Answer 8

A Latin square is a technique to control for order effects without having all possible orders.

Question 9

Learning Effect (also Practice Effect)

Answer 9

The learning, or practice effect, is an improvement in participant performance with repeated testing.

Question 10

Matched Pairs Design

Answer 10

The matched pairs design is a method of assigning subjects to groups in which pairs of subjects are first matched on some characteristic and then individually assigned randomly to groups.

Question 11

Mortality (also Attrition)

Answer 11

Mortality refers to the loss of subjects who decide to leave an experiment. Mortality is a threat to internal validity when the mortality rate is related to the nature of the experimental manipulation.

Question 12

Order Effect

Answer 12

The order effect, in a repeated measures design, is the effect that the order of introducing treatment has on the dependent variable.

Question 13

Posttest-only Design

Answer 13

A posttest-only design is a true experimental design in which the dependent variable (posttest) is measured only once, after manipulation of the independent variable.

Question 14

Practice Effect (also Learning Effect)

Answer 14

The practice effect is an improvement in participant performance with repeated testing.

Question 15

Pretest-Posttest Design

Answer 15

The pretest-posttest design is a true experimental design in which the dependent variable is measured both before (pretest) and after (posttest) manipulation of the independent variable.

Question 16

Random Assignment

Answer 16

Random assignment is the use of a random “chance” procedure (such as a random number generator or coin toss) to determine the condition in which an individual will participate.

Question 17

Repeated Measures Design (also Within-Subjects Design)

Answer 17

The repeated measures design is an experimental design in which the same subjects are assigned to each group. This is also called a within-subjects design.

Question 18

Selection Differences

Answer 18

Selection differences refer to differences in the type of subjects who make up each group in an experimental design; this situation occurs when participants elect which group they are to be assigned to.

Question 19

Within-Subjects Design (also Repeated Measures Design)

Answer 19

A within-subjects experimental design is an experiment in which the same subjects are assigned to each group. It is also called a repeated measures design.