Chapter 8

Question 1

How are all other variables controlled in experimental method

Answer 1

Experiment control

Randomization

Question 2

Confounding variable

Answer 2

Variable that varies along with the independent variable

It occurs when efffects of independent variable and an uncontrolled variable are intertwined so you cannot determine which of the variables is responsible for the observed effect

Question 3

When the results of an experiment can confidently be attributed to the effect of the independent variable, the experiment is said to have…

Answer 3

Internal validity

Question 4

How does one achieve good internal validity?

Answer 4

Researcher myst design and conduct the experiment so that only the independent variable can be the cause of the results

Question 5

A researcher using a Posttest only design must..:

Answer 5

Obtain two equivalent groups of participants

Introduce the independent variable
Measure the effect of the independent variable on the dependent variable

Question 6

Why must pisttest only design use two EQUIVALENT groups?

Answer 6

To eliminate any selectional differences

Question 7

Selection differences

Answer 7

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 8

Difference between pretext only design and pretext post test

Answer 8

In protest post test, a pretext is given before the experimental manipulation is introduced

Question 9

Why in pretext posttest, is pretext given before manipulation

Answer 9

Makes it possible to ascertain that groups were infact equivalent from the beginning

It is not always needed in a large sample of participants that has random assignment

Question 10

drop out factor is caused

Answer 10

Attrition or mortality

Question 11

Fallbacks of a pretest

Answer 11

It can sensitize participants to what you are studying, enabling them to figure out what you are studying and why

Question 12

Solomon design

Answer 12

Half of participants receive only the post test and half receive both the pre test and the post test

Question 13

Independent group design (also known as between subjects design)

Answer 13

When participants are randomly assigned to the various conditions so that the each participated in only ONE group

Comparisons are made between different groups of participants

Question 14

Repeated measure design

Answer 14

Participants receive all conditions

When each participant is measured after receiving each level of the independent variable.

(Also called within subject design)

Question 15

Random assignment

Answer 15

Decision to assign an individual to a particular condition is completely random and beyond the control of the researcher

Question 16

Advantages of repeated measure design

Answer 16

Fewer research participants are needed because each individual participated in all conditions

They are extremely sensitive to finding statistical significant differences between group.

Question 17

Two ways to assign participants to a group

Answer 17

Indenpendent group design (only participated in one )

repeated measure design (participated in all)

Question 18

Advantages of pretest post test

Answer 18

Ensure consistency (aka experimental control)

Can help with subject selection criteria

Can determine change between pretest and post test

Can determine if attrition (aka mortality) affected results

Question 19

Pre test post test disadvantages

Answer 19

Demand characteristics (like filler ideas)

Time, money, effort, etc

Question 20

How to ensure equivalency between two groups

Answer 20

Random assignment

Question 21

Repeated measures design (ak within subjects) advantages

Answer 21

Fewer Ss needegreater statistical “sensitivity” by deducting random error

Question 22

Disadvantages of experimental design

Answer 22

Order effects

Counterbalancing

Question 23

Threats to internal validity highlighted by quasi experiment designs

Answer 23

History 
Maturation 
Testing 
Instrument decay 
Progression toward the mean 
Attrition or drop out

Question 24

Order effect

Answer 24

The order of presenting the treatments effect the dependent variable

Question 25

Order effect and repeated measure design

Answer 25

A problem with repeated measure design stems from the fact that different conditions must be presented in a particular sequence

Greater recall in the high meaningful condition can be attributed to the fact that the high meaningful task came second

Question 26

Practice effect

Answer 26

Performance in the second task might improve merely because of practice gained on the first task

Question 27

Fatigue effect

Answer 27

When research participant becomes tired, bored or distracted

Question 28

Disadvantages of repeated measure design

Answer 28

Order effect

Practice effect

Fatigue effect

Carryover effect

Question 29

Carryover effect

Answer 29

When effect of first treatment carries over to influence the response of the second treatment

Ex-after reading about less sever crime, the more severe crime might seem worse to participants than it normally would

Question 30

Counterbalancing

Answer 30

When all possible orders of presentation is included in the experiment

This helps with order effect

Question 31

How to deal with order effect

Answer 31

Counterbalancing or Latin square

Time interval between treatments

Question 32

Latin actuate

Answer 32

A technique to control for order effects without having all possible orders

Each condition appears at each ordinal position

Each condition prefers and follows each condition one time

Question 33

How to counteract fatigue effect

Answer 33

A rest period/time in between treatments

Question 34

Repeated measure design over independent group advantages

Answer 34

A reduction in the number of participants is required to complete the experiment

Greater control over participant differences and thus greater ability to detect an effect of tha independent variable

Question 35

When can you not use repeated measure design

Answer 35

An experimental procedure that produces a realistically permanent change in an individual

Ex-psychotherapy treatment or surgical procedure

Question 36

Matched pair designs

Answer 36

Instead of randomly assigning participants to groups, people get matched on participant variable such as age or personality trait

The variable will be strongly related to the dependent variable

Question 37

What does a matched pair design ensure

Answer 37

That groups are equivalent prior to introduction of independent variable

Question 38

When is matching most likely used

Answer 38

When there’s only a few participants available or there is a strong relationship between dependent measure and the matching variable