Chapter 11

Question 1

Within-subjects design

Answer 1

The same participants are observed one time in each group of a research study

Question 2

Within-subjects experimental design

Answer 2

the levels of a within-subjects factor are manipulated, then the same participants are observed in each group or at each level of the factor

• researcher must:
  
  • manipulate the levels of the factor & include a comparison/ control group
  • make added efforts to control for order and time-related factors

Question 3

What are time related factors? Give some time-related factors

Answer 3

Things that must be controlled in order for a study to be an experiment

• testing effects
• maturation
• attrition
• participant fatigue
• regression toward the mean

Question 4

Participant fatigue

Answer 4

Time related factor

A state of physical or psychological exhaustion resulting from intense research demand typically due to observing participants too often, or requiring participants to engage in research activities that are too demanding

Question 5

Order effects

Answer 5

To control for time related factors researchers control for order effects

A threat to internal validity in which the order in which participants receive different treatments or participate in different groups causes changes in a dependent variable

Question 6

Carryover effects

Answer 6

A threat to internal validity in which participants in one group “carries over” or cause changes in performance in a second group

Question 7

Repeated measures design

Answer 7

we select a sample from one population & observe that one sample of participants in each group

Can be used in an experiment when researchers control for order effects and manipulate the levels of the independent variable

Question 8

Matched-samples design

Answer 8

participants are matched, experimentally or naturally, based in characteristics or traits that they share

Cannot be used in an experiment because groups are created based on preexisting characteristics of the participants, and not on a manipulation made by the researcher

Question 9

Within-subjects design advantages

Answer 9

Fewer participants are required, thus economic

A greater power to detect/find smaller differences between groups if one exists

A smaller value of error variance

Question 10

Within-subjects design disadvantages

Answer 10

Can’t use random assignment

Need to control for order effects if used