CH_09: Basic Between-Subjects Designs

Question 1

A design where different subjects take part in each condition of the experiment

Answer 1

Between-subjects design

Question 2

A process of randomization that first creates treatment blocks containing one random order of the conditions in the experiment; subjects are then assigned to fill each successive treatment block

Answer 2

Block randomization

Question 3

A condition in which subjects receive a zero value of the independent variable

Answer 3

Control condition

Question 4

The subjects in a control condition

Answer 4

Control group

Question 5

A treatment condition in which the researcher applies a particular value of an independent variable to subjects and then measures the dependent variable; in an experimental group-control group design, the group that receives some value of the independent variable

Answer 5

Experimental condition

Question 6

The general structure of an experiment (but not its specific content)

Answer 6

Experimental design

Question 7

The subjects in an experimental condition

Answer 7

Experimental group

Question 8

A between-subjects design with one IV, in which there are more than two treatment conditions

Answer 8

Multiple-groups design

Question 9

The most commonly used multiple-groups design in which the subjects are assigned to the different treatment conditions at random

Answer 9

Multiple-independent-groups design

Question 10

A mini-experiment using only a few subjects to pretest selected levels of an independent variable before conducting the actual experiment

Answer 10

Pilot study

Question 11

In drug testing, a control condition in whih subjects are treated exactly the same as subjects who are in the experimental group, except for the presence of the actual drug; the prototype of a good control group

Answer 11

Placebo group

Question 12

Creating pairs whose subjects have identical scores on the matching variable

Answer 12

Precision matching

Question 13

The technique of assigning subjects to treatments so that each subject has an equal chance of being assigned to each treatment condition

Answer 13

Random assignment

Question 14

Creating pairs of subjects whose scores on the matching variable fall within a previously specified range of scorres

Answer 14

Range matching

Question 15

Creating matched pairs by placing subjects in order of their scores on the matching varibale; subjects with adjacent scores become pairs

Answer 15

Rank-ordered matching

Question 16

A design in which two groups of subjects are exposed to different levels of the independent variable

Answer 16

Two-experimental-groups design

Question 17

The simplest experimental design, used only when two treatment conditions are needed

Answer 17

Two-group design

Question 18

An experimental design in which subjects are placed in each of two treatment conditions through random assignment

Answer 18

Two-independent-groups design

Question 19

An experimental design with two treatment conditions and with subjects who are matched on a subject variable thought to be highly related to the dependent variable

Answer 19

Two-matched-groups design

Question 20

T/F: An experiment must have at least two treatment conditions.

Answer 20

TRUE.

THE IV is manipulated such that at least two levels or treatment conditions are created.

Question 21

What are the two variations of the two-group design?

Answer 21

Two-independent-groups design and two-matched-groups design.

Question 22

T/F: In an experiment for TIGD, subjects are always randomly assigned to treatment conditions.

Answer 22

TRUE.

Even when not possible to select subjects entirely at random, the TIG design can still be used as long as subjects are randomly assigned to each group.

Question 23

T/F: In a TIG design, the makeup of one group has an effect on that of the other.

Answer 23

F.

The makeup of one group has no effect on that of the other.

Question 24

T/F: Random assignment gives us better chances of forming groups that are roughly the same on all the extraneous variables that might affect our DV.

Answer 24

T.

Random assignment controls for subject variables and guards against the possibility that subjects’ characteristics will vary systemically along with the IV.

Question 25

What type of design is the experiment where testing if a highly violent music video vs a mildly violent music video would produce more aggressiveness?

Answer 25

Two-experimental-groups design

Question 26

T/F: The more subjects we have available to assign to treatment conditions, the better the chances are that randomization will lead to equivalent groups of subjects.

Answer 26

T.

Question 27

T/F: When we use the TIGS, we assume that randomization is succesful.

Answer 27

T.

Question 28

T/F: Randomization always guarantees that treatment groups will be comparable on all the relevant extraneous subject variables.

Answer 28

F.

It is not always succesful.

Question 29

What are the three types of matching procedures?

Answer 29

• Precision matching
• Range matching
• Rank-order matching

(Used after the experiment is conducted and scores are collected)

Question 30

T/F: Statistical procedures are the same for those in matched groups and in independent groups.

Answer 30

F.

They are different.

Question 31

What design is usually needed in situations in which the amount or degree of the IV is important?

Answer 31

Multiple-groups design, where there are more than two groups of subjects and each group is run through a different treatment condition

Question 32

What type(s) of design is/are under multiple-groups design?

Answer 32

Multiple-independent groups design, in which the subjects are assigned to the different treatment conditions at random.

Question 33

What is a random number table used for?

Answer 33

Assigning subjects.

Question 34

What are the three factors the researcher considers to decide on the experimental design?

Answer 34

1. number of IVs in the hypothesis
2. number of treatment conditions needed to make a fair test of the hypothesis
3. whether the same or diff subjects are used in each of the treatment conditions

Question 35

T/F: Effect size of the IV can affect the number of participants needed in an experiment?

Answer 35

T.

Bonus: How?

Question 36

What is the simplest experimental design?

Answer 36

Two-group design

Question 37

How can matching be an advantage?

Answer 37

One can guarantee that groups start out the same on variables that matter AND if the matching variable is strongly related to the DV, matching can make treatment effects easier to detect statistically.

Question 38

T/F: Block randomization can be used to ensure that each condition has an equal number of subjects.

Answer 38

T

Question 39

T/F: It is valuable to always try to do multiple-groups design.

Answer 39

F.

Although we can get additional information from this, it is not always practical or necessary to do so. For some experimental hypotheses, just two values of the IV is sufficient.

Question 40

T/F: While a between-subjects design has fewer threats to internal validity, it also requires more participants for high statistical power compared to a within-subjects design.

Answer 40

T.

Question 41

How do you counter subject variables that confound the dependent variable in random assignment?

Answer 41

Use matching.