“To ‘learn from experience’ is to make a backward and forward connection between what we do and what we enjoy or suffer in consequence. Under such conditions, doing becomes a trying; an experiment with the world to find out what it is like; the undergoing becomes instruction—discovery of the connection of things”

John Dewey

Variable Analytic Approach

• Variable

• Property or characteristic of people or things that varies in quality or magnitude

• Constant

• Property or characteristic whose value does not change; a symbol to which only one number can be assigned

Independent Variable

• Manipulation or variation of this variable is assumed to be the cause of change in other variables– Also called antecedent variable, experimental

variable or predicator variable

Dependent Variable

• The variable of primary interest

• The variable that is influenced or changed by the independent variable– Also called the criterion variable, outcome

variable

Intervening Variable

• Presumed to explain or provide a link between independent and dependent variables

• Relationship between IV and DV is shaped by intervening variable– Also referred to as mediating or moderating

variable

IndependentAntecedentExperimentalPredictor

IndependentAntecedentExperimentalPredictor

DependentCriterionOutcome

DependentCriterionOutcome

InterveningMediating

Moderating

InterveningMediating

Moderating

The Independent variable is presumed to have an effect on or cause change in the dependent variable

The Dependent variable is influenced by changes in

the IV

The intervening variable is presumed to explain or influence the link between the IV and DV.

Examples

• People who have had formal debate training will report higher levels of aggressiveness than will people who have not had debate training

• IV: Debate training

• DV: Level of aggressiveness

• College educated individuals who have high levels of exposure to television news will report greater satisfaction with life than college-educated individuals who have low levels of exposure to television news

• IV: Exposure to TV news

• DV: Satisfaction with life

• Constant: College education

• The effect of communication competence on interpersonal solidarity will be stronger for African Americans than for European Americans

• IV: Level of communication competence

• DV: Interpersonal solidarity

• Intervening: Race

• There will be a higher frequency of tobacco-related advertisements in African-American magazines compared to similar general audience magazines

• IV: Target audience of magazine

• DV: Frequency of tobacco-related advertisements

• Volunteers will exhibit higher levels of identification with an organization’s mission than paid employees

• IV: Membership status (e.g., volunteer/paid employees)

• DV: Identification with an organization’s mission

• The use of nonverbal immediacy behaviors by physicians will increase patient satisfaction with care received

• IV: Nonverbal immediacy

• DV: Patient satisfaction

Operationalization

• How the variable is observed or measured

• Multiple operationalizations exist for most variables

• Is/does the measurement….– Practical and useful?– Justified argument?– Coincides with the conceptual definition?

Measurement

• Assigning numbers to variables according to a system

• 4 levels of measurement

• 1. Nominal (Categorical):

• #s represent absence or presence of characteristic; values indicate different categories

• Gender

• 2. Ordinal (Categorical): Uses rank order to determine categorical differences; does not tell you how much difference exists between categories

• (e.g., bronze, silver, gold)• 3. Interval (Continuous): Assigns numbers to

items as a matter of degree; intervals between numbers are equal in size

• (e.g., Likert scale)

• 4. Ratio (Continuous): extends interval to include “absolute zero”

• (e.g., scores on an exam)