 CHAPTER 4
STUDYING BEHAVIOR
 VARIABLES
 Four General Categories
 Situational variables
 Response variables
 Participant or subject variables
 Mediating variables
 MEDIATING VARIABLE
 OPERATIONAL DEFINITIONS OF VARIABLES
 Variable is an abstract concept that must be translated into concrete forms of observation or
manipulation
 Studied empirically
 Help communicate ideas to others
 RELATIONSHIPS BETWEEN VARIABLES
 Positive Linear Relationship
 Increases in one variable relate to increases in another
 Negative Linear Relationship
 Increases in one variable relative to decreases in another
 Curvilinear Relationship
 Increases in one variable relative to both increases and decreases in another
 No Relationship
 Correlation coefficient
 Relationships and Reduction of Uncertainty
 FOUR TYPES OF RELATIONSHIPS BETWEEN VARIABLES
 NONEXPERIMENTAL VERSUS EXPERIMENTAL METHODS
 Nonexperimental Method
 Direction of Cause and Effect
 The Third-Variable or Confounding Variable Problem
 Experimental Method
 Experimental Control
 Randomization
 NON-EXPERIMENTAL VERSUS EXPERIMENTAL METHODS
The casual possibilities in a non-experimental study
 INDEPENDENT AND DEPENDENT VARIABLES
 Independent = Cause
 Dependent = Effect
 CAUSALITY
 Inferences of Cause and Effect Require Three Elements:
1. Temporal precedence
2. Covariation between the two variables
3. Need to eliminate plausible alternative explanations
 ADVANTAGES OF MULTIPLE METHODS
 Artificiality of Experiments
 Ethical and Practical Considerations
 Participant Variables
 Description of Behavior
 Successful Predictions of Future Behavior
 EVALUATING RESEARCH: FOUR VALIDITIES
 Construct Validity
 Adequacy of the operational definition of variables
 Internal Validity
 Ability to draw conclusions about causal relationships from our data
 EVALUATING RESEARCH: FOUR VALIDITIES
 External Validity
 Extent to which the results can be generalized to other populations and settings
 Conclusion Validity
 Draws reasonable conclusions based upon an analysis of the data
 Test Validity
Construct Validity
Does the scale correlate with the theorized psychological construct?
Evaluate the adequacy of the operational definition.
•
Convergent – degree to which operation is similar to others it should be similar to (other tests
of the same construct)
•
Divergent – degree to which it is not similar to others it should not be similar to.
Content Validity
Extent to which test represents all facets of a given social construct – experts decide
 Test Validity (cont)
Criterion validity
Measure of how well one variable predicts outcome based on information from other variables – how
closely related to the real world
 Concurrent – relation to other concrete criteria assessed simultaneously
 Predictive – degree to which it predicts future events