Experimental Research

Question 1

What is the purpose of experimental research?

Answer 1

To determine cause and effect (manipulating the IV to see its effect on the DV)

Question 2

What are the criteria to establish cause and effect?

Answer 2

1. The cause must come before (precede) the effect
2. The cause and effect must be correlated
3. The correlation cannot be explained by another variable

Question 3

True or False?
Cause and effect are established by statistics.

Answer 3

False. Cause and effect are established by logical thinking and well-designed experiments.

Question 4

What can statistics do?

Answer 4

1. Reject the null hypothesis
2. Establish effect size

Question 5

What is internal validity?

Answer 5

Determines if the results are due to the treatment.

Question 6

What do you need to show internal validity?

Answer 6

Control over the participants and environment.

Question 7

What is external validity?

Answer 7

Determines if the results are generalizable.

Question 8

What do you need to show external validity?

Answer 8

A sample that looks like (represents) our population.

Question 9

What is the relationship between external and internal validity and why?

Answer 9

1. Inverse
2. Experiments have high control, the real world has little control

Question 10

What are the threats to internal validity?
Give examples for them.

Answer 10

1. History (Pandemic)
2. Maturation (Puberty)
3. Testing (Pre-test)
4. Instrumentation (Data Error)
5. Statistical Regression (Highest move towards middle)
6. Selection Bias (Different groups to begin)
7. Experimental Mortality (Withdrawing)
8. Selection - maturation interaction (groups maturing at different rates)
9. Expectancy (may treat someone better)

Question 11

Which threat(s) does randomization control?

Internal Validity

Answer 11

Maturation, History, Statistical Regression, Selection Bias, Selection-maturation interaction

Question 12

What threat(s) does calibration control?

Answer 12

Instrumentation

Question 13

What threat(s) does interest/incentives control?

Internal Validity

Answer 13

Mortality

Question 14

What threat(s) does study design control?

Internal Validity

Answer 14

Testing, expectancy

Question 15

What are the threats to external validity?
Give examples.

Answer 15

1. Testing (pre-test)
2. Selection Bias (may only work for the selected population)
3. Setting (Very controlled settings)
4. Multiple Treatments (getting more than one treatment does not happen often in real-world)

Question 16

What threat(s) does research design control?

External Validity

Answer 16

Testing, Multiple Treatment Interference

Question 17

What threat(s) does randomization control?

External Validity

Answer 17

Selection Bias

Question 18

What threat(s) does the researcher control?

Answer 18

Experimental Setting

Question 19

When looking at experimental designs… what does ROT stand for?

Answer 19

R - Random
O - Observation
T - Treatment

Question 20

Describe pre-experimental designs

Answer 20

1. Control very few threats
2. Not good designs
3. None are randomized

Question 21

What are the pre-experimental designs and what is wrong with them?

Answer 21

1. One-shot study (nothing to compare and no internal validity)
2. One-group Pretest-Posttest Design (nothing to compare)
3. Static Group Comparison (groups are not randomized)

Question 22

Which design is this:

T O

Answer 22

One-shot study

Question 23

Which design is this:

O T O

Answer 23

One-group Pretest-Posttest Study

Question 24

Which design is this:

T O
O

Answer 24

Static Group Comparison

Question 25

Describe True experimental designs

Answer 25

1. All have randomization
2. Have control over IV
3. Have control groups
4. Can control many threats

Question 26

What are the true experimental designs and what do they show?

Answer 26

1. Randomized Groups (Randomization allows us to assume differences are due to treatment)
2. Randomized Groups Pretest-Postest ((Randomization allows us to assume differences are due to treatment with a pretest)
3. Solomon Four (controls testing threat)
4. Quasi-Experimental (fits real world)
5. Non-equivalent Control Group (Very common)
6. Time Series (show change over time)
7. Reversal Design (want stability over time)
8. Switched Replications (No problems)

Question 27

What is wrong with Solomon Four and Switched Replications?

Answer 27

Solomon Four = Double the subjects and which tests
Switched replications = A lot of subjects and pain to analyze

Question 28

What is wrong with Quasi-experimental?

Answer 28

Not randomized

Question 29

Which design is this:

R T O
R O

Answer 29

Randomized Groups

Question 30

Which design is this:

O T O
O O

Answer 30

Non-equivalent Control Group

Question 30

Which design is this:

O O O O T O O O O

Answer 30

Time Series

Question 31

Which design is this:

R O T O
R O O

Answer 31

Randomized Groups Pretest - Posttest

Question 32

Which design is this:

R O T O
R O O
R T O
R O

Answer 32

Solomon Four

Question 33

Which design is this:

O O T O O T O O

Answer 33

Reversal Design

Question 34

Which design is this:

O T O O O
O O T O O
O O O T O
O O O O T

Answer 34

Switched Replications