Chapter #10

Question 1

Within-Subjects Designs (Pretest-Posttest Design):

Answer 1

Measure the dependent variable before and after exposing participants to a treatment or intervention
Allows for the evaluation of potential changes in participants due to exposure to a particular treatment

Question 2

Within-Subjects Designs (Repeated-Measures Design):

Answer 2

We expose participants to each level of the independent variable, measuring each participant on the dependent variable after each level (ex. measure mood after listening to different musical pieces)

Question 3

The Advantages of Within-Subjects Designs (Statistical Power):

Answer 3

With the same participants in every condition, we do not have to worry about individual differences between groups. This increases the likelihood of rejecting the null hypothesis when the null hypothesis is false

Question 4

The Advantages of Within-Subjects Designs (Efficiency):

Answer 4

For a given number of data points, fewer participants are required for a within-subjects design than for a between-subjects design

Question 5

Sequence for Order Effects (Practice Effect):

Answer 5

Changes in participants’ responses or behaviour due to increased experience with the measurement instrument

Question 6

Sequence for Order Effects (Fatigue Effect):

Answer 6

Deterioration in measurements that are due to participants becoming tired or less attentive during the course of the study

Question 7

Controls for order effects (Randomixing the Order of Levels):

Answer 7

Vary the sequence of experimental conditions so that they are not always in the same order for all participants. The problem with randomly selecting the next condition for each participant is that you may select some sequences more frequently and other sequences less frequently or not at all

Question 8

Controls for order effects (Counterbalancing):

Answer 8

All potential treatment sequences are used in a within-subjects design; first identify all possible treatment sequences and then randomly assign participants to each sequence

Question 9

Controls for order effects (Latin Square Design):

Answer 9

• Tests order effects by making order sequence its own independent variable
• A counterbalancing strategy whereby each experimental condition appears at every position in the sequence order equally often
• Used in larger repeated-measures designs

Question 10

When to Use a T-test for Dependent Means (AKA a paired-samples t-test):

Answer 10

One independent variable with two levels/conditions as part of a within-subjects design

Question 11

What is a Behavioral Diary?

Answer 11

A self-report data collection strategy where individuals record their behaviors and associated feelings as they occur

Question 12

What is a Baseline Measurement?

Answer 12

The initial assessment of a participant at the onset of a study of any intervention or treatment

Question 13

Advantages of a Within-subjects Design (3):

Answer 13

1. Can address research questions involving change or relative comparisons
2. Fewer research participants needed for adequate statistical power
3. Individual differences are constant across comparison group

Question 14

Disadvantages of a Within-Subjects Design (3):

Answer 14

1. Potential external validity concerns
2. Potential logistical challenges
3. Potential threats to internal validity

Question 15

What is Attrition or Mortality:

Answer 15

The differential dropping out of participants from a study

Question 16

What is the Solution to Attrition or Mortality?

Answer 16

Make continuation in the study appealing or nonthreatening

Question 17

What is the Testing Effect?

Answer 17

A threat to the internal validity of a study where participants scores may change on subsequent scores may change on subsequent measurements simply because of their increased familiarity with the instrument

Question 18

What is the Solution to the Testing Effect (2)?

Answer 18

1. Use distractor items or tasks
2. Increase the time between the different conditions

Question 19

What is the Instrumentation Problem?

Answer 19

A threat to internal validity - a change in how a variable is measured or administered during the course of a study

Question 20

What is the Solution to the Instrumentation Problem?

Answer 20

Maintain consistency in the measurement instrument and how it is administered throughout the study

Question 21

What is the Threat of Maturation?

Answer 21

A threat to the internal validity of a study stemming from either long/short-term physiological changes occurring naturally within the participants that may influence the DV

Question 22

What is the Solution to Maturation?

Answer 22

Use a comparison group not exposed to the treatment or intervention to determine if maturation is a potential threat

Question 23

What is the Threat of History?

Answer 23

A threat to internal valididty of a study due to external event potentially influencing participants’ behavior during the study

Question 24

What is the Solution to the Threat of History?

Answer 24

Difficult to prevent; record in the researcher’s notes any unexpected occurrences

Question 25

What is the Order Effect?

Answer 25

A threat to the internal validity in a within-subjects design resulting from influence that the sequence of experimental conditions can have on the DV

Question 26

What is the Practice Effect (types of Order Effect)?

Answer 26

Changes in a participant's responses or behavior due to increased experience ith the measurement instrument, not the variable under investigation

Question 27

What is the Solution to the Practice Effect (2)?

Answer 27

1. Provide participants with extensive training on the task before starting the actual study 2. Do a trial run so that participants can learn and improve before measurement begins

Question 28

What is the Fatigue Effect (type of Order Effect)?

Answer 28

Deterioration in quality of measurements due to participants becoming tired, less attentive, or careless during the course of the study

Question 29

What is the Solution to the Fatigue Effect (3)?

Answer 29

1. Make the task more interesting 2. Keep the tasks brief 3. Keep the tasks from being too taxing

Question 30

What is the sensitization Effect (type of Order Effect)?

Answer 30

Continued exposure to experiment at conditions in a within-subjects study increasing the likelihood of hypothesis-guessing potentially influencing participant's responses in later experimental conditions

Question 31

What is the Solution to the Sensitization Effect (2)?

Answer 31

1. Misleading participants as to the study's purpose 2. Use other strategies that prevent participants from knowing what you are varying in your study

Question 32

What is the Carryover Effect (type of Order Effect)?

Answer 32

Exposure to earlier experimental conditions influencing responses to subsequent conditions

Question 33

What is the Solution to the Carryover Effect (2)?

Answer 33

1. Lengthen the time between treatments 2. Use other strategies that clear the effect before exposing participants to the next condition

Question 34

Minimizing Potential Order Effects - Counterbalancing:

Answer 34

Identifying and using all potential treatment sequences in a within-subjects design

Question 35

Minimizing Potential Order Effects - Latin Square Design:

Answer 35

A counterbalancing strategy where each experimental condition appears at every position in the sequence order equally often