# Behavioral Research Chapter Four Studying Behavior.

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Behavioral Research Chapter Four Studying Behavior

Introduction Examine the basic issues and concepts necessary for understanding behavioral research. Look at the nature of variables, including measurement, types of relationships, and general methods for studying these relationships.

Variable- (def) any event, situation, behavior or individual characteristic that has two or more levels or values on which they can vary. Four General Categories of Variables  Response Variables  Situational Variables  Participant (Subject) Variables  Mediating Variables

Operational Definitions of Variables operationally definition  defines a concept by specifying precisely how the concept is measured or manipulated in a particular study.

How does it help us to operationally define our variables?  Defining an abstract term helps you to determine if your study (your focus) is too vague or not.  Having operationally defined our variables also helps us to communicate our ideas to others.

Relationships Between Variables Four most common relationships found in research are:  Positive liner relationship- increases in the values of one variable are accompanied by increases in the values of the second variable.  Negative linear relationship- Increases in the values of one variable are accompanied by decreases in the values of the other variable.  Curvilinear relationship Increases in the values of one variable are accompanied by both increases and decreases in the values of other variables.  No relationship- When there is no relationship between the two variables the graph is a straight line.

Correlational coefficient  (def) a numerical index of the strength of the relationship between variables.  When variables are highly correlated, this indicates there is little deviation in the general pattern of the data.  When two variables are weakly correlated, there are either many Participants who deviate from the general pattern of the data or the two variables don’t effect each other that strongly.

Nonexperimental vs. Experimental Methods  Nonexperimental method  relationships are studied by making observations or measures of the variables of interest.  When the two variables vary together---we say that they are correlated.  While we can say that there is a relationship between the two variables, we cannot say we can determine causality.  CORRELATION DOES NOT IMPLY CAUSATION!!

Problems with Non-Experimental Method Direction----cannot tell which variable causes the other. Third Variable problem: There may be a relationship between the two variables because some other variable causes both. (also called confounding variables).

Experimental method  Involves direct manipulation and control of variables.  The researcher manipulates the variable of interest and then observes (measures) the response.  Because one variable is manipulated while the other is measured, researchers can now comment about the direction of cause and effect.  The experimental method helps to eliminate the ambiguity found in the results

Extraneous variables  variable that interferes with the results, making it impossible for the researcher to draw meaningful conclusions about the effect of the variables. Experimental Control-with experimental control all extraneous variables are kept constant, and therefore cannot be responsible for the results of the experiment. Randomization- The experimental method ensures that extraneous variables, in which control would be difficult, are equalized through random assignment.

Independent and Dependent Variables Independent variable  what’s manipulated by the experimenter—the variable that is considered to be the cause. Dependent variables  Ps’ response, or what is measured—the variable that is the effect of the dependent variable.

Two Kinds of Independent Variables Manipulated I.V. Non-Manipulated I.V. Constant  a variable that is held constant, in order to prevent it from varying, and possibly affecting the outcome of the experiment.

Evaluating Research-Three Validities Construct Validity  Internal validity  External validity 