CreswellUnderstanding the Relationships Between Variables and

Theory in Media Effects Research

What is the point?

We are trying to explain or predict the cause and effect relationship between exposure to media and a change in

attitudes or behavior.

Exposure to media—cause

Change in attitudes or behavior—effect

Variables

A characteristic or attribute of an individual or an organization that can be measured or observed and that varies among the

people or organization being studied.

Variables are distinguished by two characteristics

temporal order and measurability

Variables

Temporal order means that one variable precedes the other in time.

Independent variables—those that cause, influence or effect outcomes. They are also called the treatment, manipulated,

antecedent and predictor variables. (Often represented by X)

Dependent variables—the outcomes or results of the influence of the independent variable. Other names are outcome, criterion and effect

variables. (Often represented by Y)

Variables

Measurability means the variable can be counted or observed.

Researchers construct operational definitions to demonstratemeasurability.

Operational Definitions

Theory

An interrelated set of variables formed into propositions or hypotheses that specify the relationship among the variables

(typically in magnitude and direction).

Use the rainbow metaphor—it ties together variables and provides an overarching explanation for how and why one

would expect the independent variable to explain or predict the dependent variable

Variables and Theory

Types of theoretical relationships

Research purpose

Research questions

Hypotheses (directional and nondirectional)

Variables and Theory

Research purpose—a statement about the independent and dependent variables.

The purpose of this study is to investigate the influence of exposure to X media on the change in Y attitudes or behavior.

Variables and Theory

Research question—the relationship between the independent and dependent variables stated as a question.

What is the effect of exposure to X media on Y attitudes or behavior?

Variables and Theory

Hypotheses—a statement that predicts the outcome of a study

Nondirectional hypothesis—There is a relationship between exposure to X media and a change in Y attitudes or behavior.

Directional hypothesis—Exposure to X media will result in a positive change in Y attitudes or behavior.

TOP HAT Quiz

Identify the parts of a proposal