• frequency distributions
  
• measures of central tendency
  
• measures of dispersion
  

Purpose of Inquiry: Explanation
Establishing a causal relationship: 3 components

1. Time order: cause precedes effect
   
   • based on theory and observation
     
2. Correlation: cause and effect have a tendency to occur/not occur together
   
   • based on tabular analysis or regression
     
   • remember the four key questions to this particular aspect of establishing correlation
     
   1. Is there a relationship?
      
      • Changes in column percentages across categories of independent variable.
        
   2. Is the relationship strong?
      
      • magnitude of percentage changes.
        
      • magnitude of measures of association. (know which ones to use when).
        
   3. What is the direction of the relationship? (ordinal or interval/ratio only)
      
      • distibution of cases within the table
        
      • sign of measure of association
        
   4. Is the relationship statistically significant?
      
      • to what extent is this relationship due to sampling error?
        
        • probability values: how are they interpreted?
          
        • You should also be familiar with Type I and Type II errors.
          
3. Accounting for other possible explanations
   
   • Elaboration-the introduction of a control variable
     
     • Two questions:
       
       1. What happens to the relationship when the control variable is introduced?
          
       2. Is the control variable antecendent or intervening?
          
       
       

• Regression: Analysis of Interval/ratio level variables
  
  • Allows one to simultaneously test multiple hypotheses (i.e. do steps B and C above at the same time.)
    
    • Know the interpretation of:
      
      • R ²
        
      • b and BETA
        
      • t and it’s associated probability