Chapter 4 - Methods in Behavioral Research

Variable

- Any event, situation, behavior, or individual characteristic that varies
- Any variable must have two or more levels of values
- Four General Categories of Variables:
- Situational variables
- Response variables
- Participant or subject variables
- Medi

Mediating variable

- the variable that causes mediation in the dependent and the independent variables. In other words, it explains the relationship between the dependent variable and the independent variable.

Operational definition

- the set of procedures used to measure or manipulate it
- Variable is an abstract concept that must be translated into concrete forms of observation or manipulation
- Studied empirically
- Help communicate ideas to others

Wong-Baker FACES Pain Rating Scale

- Used for a child

Construct validity

- Concerns whether our methods of studying variables are accurate
- Refers to the adequacy of the operational definition of variables:
- Does the operational definition of a variable actually reflect the true theoretical meaning of the variable?

Relationships between variables

- Positive Linear Relationship
- Negative Linear Relationship
- Curvilinear Relationship
- No Relationship

Positive Linear Relationship

- Increases in one variable relate to increases in another

Negative Linear Relationship (Inverse relationship)

- Increases in one variable relative to decreases in another

Curvilinear Relationship

- Increases in one variable relative to both increases and decreases in
another
- Included U-shaped and Inverted U-shaped curves
- Sometimes referred to as a "nonmonotonic function

No Relationship

r = 0

Correlation coefficient

- A numerical index of the strength of relationship between variables
- r cannot be less than 0, more than 1 (+ or - just tell us direction)
- Interpretation of whether r is strong, mediate, or weak depends on each data

Random variability

- Uncertainty
- Randomness in events
- Research is aimed at reducing random variability by identifying systematic relationships between variables
- e.g. Some people like to shop and others do not

Nonexperimental method

- Relationships are studied by making observations or measures of the variables of interest
- Direction of Cause and Effect Problem
- The Third-Variable or Confounding Variable Problem
- Must not determine about cause and effect

Experimental method

- Experimental Control (manipulation of variables)
- Randomization

Direction of Cause and Effect

- With nonexperimental method, it is difficult to determine which variable causes the other (e.g. coffee ? Anxiety? OR anxiety ? coffee?)

Third variable problem

- There may be a relationship between the two variable because SOME OTHER variable causes both variables
- A third variable is any variable that is extraneous to the two variables being studied
- "Spurious relationship

Confounding variable

- A third variable that is not controlled in a research investigation
- In an experiment, the experimental groups differ on both the independent variable and the confounding variable

Experimental control

- Eliminating the influence of an extraneous variable on the outcome of an experiment by keeping the variable constant in the experimental and control groups
- Only difference between groups should be the manipulated variable (IV)

Randomization

- Controlling for the effects of extraneous variables by ensuring that the variables operate in a manner determined entirely by chance
- In case of participants arriving for the experiment at various times during several days or weeks, the researcher uses

Independent variable

- The variables that are considered to be the "cause"
- Usually MANIPULATED by the researcher

Dependent variable

- The variables that are considered to be the "effect"
- Usually MEASURED by the researcher

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

Internal validity

- Refers to the accuracy of conclusion about cause and effect
- Ability to draw conclusions about causal relationships from our data
- A study has high internal validity when strong inferences can be made that one variable caused changes in the other vari

External Validity

- Concerns whether we can generalize the findings of a study to other settings
- Extent to which the results can be generalized to
other populations and settings
- Stronger the internal validity, weaker the external validity (less likely to happen in gene

Conclusion validity

- Draws reasonable conclusions based upon an analysis of the data

Choosing a method

- Artificiality of Experiments
- Ethical and Practical Considerations
- Participant Variables
- Description of Behavior
- Successful Predictions of Future Behavior
- Advantages of Multiple Methods

Artificiality of experiments

- IV is manipulated within the carefully controlled confines of a laboratory
- This procedure permits relatively unambiguous inferences (strong internal validity) concerning cause and effect and reduces the possibility that extraneous variable could influ

Field experiment

- An experiment that is conducted in a natural setting rather than in a laboratory setting
- IV is manipulated in a natural setting
- A confederate may create IV (situation)

Ethical and Practical Considerations

- Sometimes the experimental method is not a feasible alternative because experimentation would be either unethical or impractical
- e.g. Child-rearing,
- "ex post facto

Ex post facto design

- "after the fact"
- Groups are formed on the basis of some actual difference rather than through random assignment as in an experiment

Participant Variables (subject variables; personal attributes)

- Characteristics of individuals, such as age, gender, ethnic group, nationality, birth order, personality, or marital status

Advantages of multiple methods

- Complete understanding of any phenomenon requires study using multiple methods, both experimental and nonexperimental.