Unit 3: Chapter 6-Validity

Question 1

Define: validity

Answer 1

an indication of accuracy in terms of the extent to which a research conclusion corresponds with reality

Question 2

Define: Internal Validity

Answer 2

extent to which a study provides evidence of a cause-effect relationship between the independent and dependent variables (142)

Question 3

Define: Construct Validity

Answer 3

extent to which the results support the theory behind the research

Question 4

Define: External Validity and explain the difference between it and ecological validity

Answer 4

how well the findings of an experiment generalize to other situations or populations

eco v: how well the experiment applies to real world situations

Question 5

Define: statistical conclusion validity

Answer 5

extent to which data are shown to be the result of cause-effect relationships rather than accident

Question 6

Define: history

Answer 6

Events that occur outside of the experiment that could influence the results of the experiment

Question 7

Define: maturation

Answer 7

a source of error in an experiment related to the amount of time between measurements (kids growing older between tests for example)

Question 8

Define: effects of retesting

Answer 8

performance on a second test is influenced by simply having taken a first test

Question 9

Define: regression effects

Answer 9

tendency of subjects with extreme scores on a first measure to score closer to the mean on a second testing

Question 10

Define: selection

Answer 10

a confound that can occur due to assignment of subjects to groups (as opposed to random selection)

Question 11

Define: mortality

Answer 11

the dropping out of some subjects before an experiment is completed, causing a threat to validity

Question 12

Define: Role demands (demand characteristics)

Answer 12

partici- pants’ expectations of what an experiment requires them to do

Question 13

Define: randomization

Answer 13

unbiased assignment pro- cess that gives each subject an equal and independent chance of being placed in every condition

Question 14

Define: matching

Answer 14

control procedure to ensure that experimental and control groups are equated on one or more variables before the experiment

Question 15

Define: statistical control

Answer 15

mathematical means of comparing subjects on paper when they cannot be equated as they exist
in fact (177)

Question 16

Define: replicability

Answer 16

replication: repeating an experiment to see if the results will be the same

Question 17

Define Power

Answer 17

the probability of rejecting the null hypothesis when it is, in fact, false (relevant to statisitcal conclusion validity

Question 18

What is meant by confounding?

Answer 18

error that occurs when the effects of two variables in an experiment cannot be separated, resulting in a confused interpretation of the results

Question 19

Why is confounding particularly acute in research in which a subject variable is used?

Answer 19

All of the factors that make up the subject variable are confounding variables.

Question 20

List the seven major threats to internal validity

Answer 20

1) Ambiguous temporal precedence
2) History
3) Maturation
4) Effect of testing (repeat testing)
5)Regression effect
6) selection
7) mortality

Question 21

What is the regression effect? When does it arise?

Answer 21

tendency of subjects with extreme scores on a first measure to score closer to the mean on a second testing
-When one assumes correlation between two variables without enough data (kid does good thing without praise=praise is not useful)

Question 22

What is mortality and when is it a threat to internal validity?

Answer 22

the dropping out of some subjects before an experiment is completed, causing a threat to validity

When it heavily skews the difference between groups (weight losee example p.149)

Question 23

Briefly describe two threats to construct validity

Answer 23

Loose Connection Between Theory and Method
-unsure of the validity of the method or measure used (cat aggression can be fighting or hunting)

Ambiguous Effect of Independent Variables
-when the experimenter and the P have different expectations?? (You werent concerned about how this tasted right?-participant trying to do something else)

Question 24

Briefly describe three threats to external validity

Answer 24

Other Subjects (college students)
Other Times
Other Settings

Question 25

What are the two broad categories of bias resulting from the interaction between experimenter and subject?

Answer 25

Subject bias Experimenter bias

Question 26

How can demand characteristics be overcome?

Answer 26

1) decieve the partipants 2) use a measure that is not likely going to impact a p's guesses about the experiment (few people are going to notice the amount of chairs in a room for example)

Question 27

Define subject variable

Answer 27

when partici- pants are selected according to the presence or absence of a condition and not selected simply to have a condition assigned to them. (143)

Question 28

What is ambiguous temporal precedence in relation to internal validity?

Answer 28

ATP is one of the major threats to internal validity that shows "two variables are related, it is not clear which one is the cause and which one is the effect"

Question 29

Define random error

Answer 29

that part of the value of a variable that can be attributed to chance