Research Methods Final Exam

Correlation

Relationship between two variables

What does causation require? (3 things)

1. Correlation- relationship between two variables

2. Directionality/ Temporal Precedence- cause must come before the effect

3. Eliminate Other Explanations- eliminate 3rd variables and other explanations through experimental control (if successful, then there is strong internal validity)

What are 4 elements of research study?

Manipulation

• Independent variable- the cause under investigation; what the experimenter manipulates

• Participant variable- the cause under investigation that can’t be manipulated (e.g. race, gender, etc.)

Measurement

• Dependent variable- the effect that experimenters measure

Comparison

Control

• Control for extraneous variables and confound variables

Manipulation

- change variable to create multiple treatment conditions of the independent variable

Types of Manipulations (3 types)

1. Environmental manipulations- modifications of the participant’s physical or social environment using confederates

2. Instructional manipulations- vary the independent variable through the verbal instructions that participants receive

3. Invasive manipulations- create physical changes in the participant’s body through surgery or the administration of drugs

Treatment Conditions

2 or more versions of the independent variable

(e.g. IV= exposure to video games: Treatment 1= 0 hours playing, Treatment 2= 3 hours hours playing, Treatment 3= 6 hours playing)

Which variable, independent variable or dependent variable, usually comes before the action word in a research question?

Independent Variable

Which variable, independent variable or dependent variable, usually comes after the action word in a research question?

Dependent Variable

What does an experiment always require?

Comparison

Control groups

-group that does not receive manipulation (zero level of the independent variable)

-control groups provide a standard of normal/baseline behavior against which the treatment condition is compared to

What is the placebo effect?

The placebo effect is when you get a response out of the participants even though they had no actual treatment (expectation creates the effect).

Placebo is a form of a control group (giving pretend treatment)

Measurement

• A second variable is measured across each condition

• The dependent variable is what is getting measured

(e.g. IV= Exposure to video games, Treatment 1= 0 hours playing—→ recorded number of penalties in soccer game, Treatment 2= 3 hours playing—→ recorded number of penalties in soccer game, Treatment 3= 6 hours playing—→ recorded number of penalties in soccer game, DV= # of penalties)

Comparison

Scores in one treatment are compared to scores in another treatment

Control

• eliminating confound variables

• all other/extra variables are controlled for

Extraneous Variable

• A variable that is not controlled or manipulated

Confounding Variable

• An extraneous variable that systematically varies with the IV and can explain the results

(e.g. low SES, abusive parents, etc..)