What are VARIABLES and how do we use

What are VARIABLES and how do we use them to address our research question?

Variables: Any characteristic that tends to differ from individual to individual ie) height, weight, gender. . CONSTANT: A variable that is the same for all subjects. ie) If all subjects were 10 years old, age would not be a variable but a constant. .

What types of Variables do we use? êIndependent variables êDependent variables êConfounding variables/Extraneous variables êControl variables

Independent vs Dependent Variables? Cannot have independent without a dependent variable and visa versa.

Independent Variables: The variable that is being manipulated. The causative variable in the cause-effect relationship.

Dependent Variables The “Effect” or “Yield”of the independent variable.

Example: The independent variable is being intentionally manipulated to produce changes in the dependent variable. A new method (independent variable) is being used to improve learning of research techniques (dependent variable).

Confounding Variables Traits or conditions whose presence are often unsuspected, may taint research outcomes. 1. Intervening variables 2. Organismic variables 3. Extraneous variables

Intervening Variables Traits inherent in human subjects that may exert unanticipated influence on dependent variables. ie) We use new method to teach research techniques. Dependent variable may be influenced by: intelligence, motivation, student liking the teacher.

Independent Variable (Intervening Variable) Dependent Variable Teaching Method Motivation Liking Teacher Research Technique = FUN!!!!! Achievement

Controlling for Confounding variables: ê Randomly select subjects so variables are present equally in all groups. ê Extraneous variables removed or attended to. ê Intentionally excluding subjects if they have organismic traits that preclude performing in accord with ability. ê Undesired effects of intervening variables (if measurable) can be removed through statistical procedures.

Control Variables: • A factor that could possibly influence the results and that is kept our of the study. – Suppose that you are studying physical fitness measures of students in a 6 th grade class. Suppose five students also play soccer. What might you want to control for in this study?