II. SCIENTIFIC METHODS OF INVESTIGATION 

     A. Methods of Observation 

          1. Case Studies - 

          2. Surveys - 

          3. Testing - 

          4. Naturalistic Observations / Field Studies - 

          5. Laboratory Observations - 

     B. The Correlation Method 

          Correlational Studies - 

     C. The Experimental Method 

          Experiments - 

III. "THE EXPERIMENTAL METHOD" IN 7 EASY STEPS 

     1. Develop testable hypotheses. 

          A. The Null Hypothesis - 

          B. The Alternative Hypotheses - 

          C. The Experimental Hypothesis - 

     2. Review the Literature. 

     3. Design the Experiment. 

          A. Variables: 

               (1). Independent Variable - 

               (2). Dependent Variable - 

               (3). Extraneous Variables - 

                    Methods of Control: 

                         a. Hold Constant - 

                         b. Allow Random Variation - 

          B. Groups 

               (1) Experimental Group - 

               (2) Control Group - 

               (3) the group that gets the Placebo - 

          C. Population v. Sample 

          D. Construct v. Observable Behavior 

          E. Operational Definitions 

     4. Collect the Data. 

     5. Analyze the Data: 

          A. Descriptive Statistics - 

               (1) Measures of Central Tendency - 

                    a. Mean - 

                    b. Median - 

                    c. Mode - 

               (2) Measures of Variability - 

                    a. Range - 

                    b. Standard Deviation (S.D.) - 

          B. Correlation - 

               (1) Direction - 

               (2) Strength - 

          C. Inferential Statistics - 

     6. Draw Conclusions from the Data. 

          A. Probability Levels/Probability Statements: 

               p<.05 = 

               p<.01 = 

               p<.001 = 

          B. Accept the Null Hypothesis, OR, 
              Reject the Null Hypothesis, and Accept the appropriate Alternative Hypothesis. 

     7. Report your Conclusions. 
 

WHERE TO GO FROM HERE? 
If the topics in this chapter and/or presentation are of particular interest to you, you might be interested in enrolling in one of the following TCC courses: 

PSY 2223 Behavioral Statistics