Chapter 5 BRT: Theoretical framework and hypothesis development

Four main types of variables

- The dependent variable: a variable of primary interest to the researcher. - The independent variable: a variable that influences the dependent variable in either a positive or a negative way. - The moderating variable: a variable that has a strong contingent effect on the independent variable-dependent variable relationship. - The mediating variable: a variable that surfaces between the time the independent variables start operating to influence the dependent variable and the time their impact is felt on it

negative case method

A new discovery, through disconfirmation of the original hypothesis, enables the researcher to revise the theory and the hypothesis until such time as the theory becomes robust.

The process of building a theoretical framework includes

- Introducing definitions of the concepts or variables in your model. - Developing a conceptual model that provides a descriptive representation of your theory. - Coming up with a theory that provides an explanation for relationships between the variables in your model.

The steps to be followed in hypothesis testing are

- State the null and the alternate hypotheses. - Choose the appropriate statistical test depending on whether the data collected are parametric or nonparametric. - Determine the level of significance desired (p = 0.05, or more, or less). - See if the output results from computer analysis indicate that the significance level is met

A null hypothesis

a hypothesis set up to be rejected in order to support an alternate hypothesis, labeled H A . Typically, the null statement is expressed in terms of there being no (significant) relationship between two variables or no (significant) difference between two groups

To examine whether or not the conjectured relationships or differences exist, these hypotheses can be set as:

a proposition or in the form of if-then statements.

hypothesis

a tentative, yet testable, statement, which predicts what you expect to find in your empirical data

Hypothesis development

formulating testable statements

Directional hypotheses

hypotheses in which the direction of the relationship between the variables (positive/negative) is indicated

Nondirectional hypotheses

hypotheses that do postulate a relationship of difference, but offer no indication of the direction of these relationships or differences.

What is being done with new hypotheses not originally thought of, or which have been previously untested?

might be developed after data are collected

The independent variable helps to explain what?

the variance in the dependent variable; the mediating variable surfaces at time t2 as a function of the independent variable, which also helps us to conceptualize the relationship between the independent and dependent variables; and the moderating variable has a contingent effect on the relationship between two variables

The alternate hypothesis

which is the opposite of the null, is a statement expressing a relationship between two variables or indicating differences between groups.

To establish that change in the independent variable causes a change in the dependent variable, all four of the following conditions should be met

- The independent and the dependent variable should covary: a change in the dependent variable should be associated with a change in the independent variable. - The independent variable should precede the dependent variable: there must be a time sequence in which the two occur: the cause must occur before the effect. - No other factor should be a possible cause of the change in the dependent variable: the researcher should control for the effects of other variables. - A logical explanation (a theory) is needed and it must explain why the independent variable affects the dependent variable.

There are three basic features that should be incorporated in any theoretical framework

- The variables considered relevant to the study should be clearly defined. - A conceptual model that describes the relationship between the variables in the model should be given. - There should be a clear explanation of why we expect these relationships to exist.

The need for a theoretical framework

A theoretical framework represents your beliefs on how certain phenomena (or variables or concepts) are related to each other (a model) and an explanation of why you believe that these variables are associated with each other (a theory)

Variables

A variable is anything that can take on differing or varying values