Reminders
     Final drafts of the APA Style Paper are due 
        in lecture next Wednesday (Nov 19)
                                      
     Statistics
     Descriptive Statistics
        Describe the data you collected from the 
           sample
     Inferential Statistics
        Making inferences about the population from 
           the data collected from the sample
        Generalize results from study to the population
                                      
     Inferential Statistics
     Example Experiment:
             Group A - gets treatment to improve memory
             Group B - gets no treatment (control)
          After treatment period test both groups for memory
          Results: 
             Group A’s average memory score is 80%
             Group B’s average memory score is 76%
          Is the 4% difference a “real” difference (statistically 
            significant) or is it just sampling error?
                                          
     Inferential Statistics
     This type of statistics is based on making 
        hypotheses and testing them
     Five main steps to test hypotheses
                                      
     Testing hypotheses
     Step 1: State your hypotheses 
     Step 2: Set your criteria
     Step 3: Collect your data from your sample
     Step 4: Compute your test statistics
     Step 5: Make a decision about your 
        hypotheses
        Reject your null hypothesis
        Fail to reject your null hypothesis