Hypothesis Tests
      Parametric Tests - tests about specific 
                                        2
        population parameters (μ, σ , etc.)
         –Is μ  different from a predetermined 
              1
          value?
         –Is μ  different from μ  ?
              1                2
      Non-Parametric Tests - tests about the 
        shape of the population (medians?)
         –Is this population different from another 
          population?
    Hypothesis Tests
     Non-Directional Hypothesis
       –Is μ  different from μ  ?
           1             2
       –Is the distribution of scores in group 1 
        different than those in group 2?
     Directional Hypotheses
       –Is μ  greater than μ  ?
           1            2
       –Is μ  less than μ  ?
           1         2
       –Is the distribution of scores in group 1 to 
        the right (greater than) of those in group 
        2?
  The Six-Steps of
  Hypothesis Testing
  1. State and Check Assumptions
  2. Generate Null and Alternative 
   Hypotheses
  3. Chose the Sampling Distribution of the 
   Test Statistic
  4. Set Significance Level
  5. Compute the Test Statistic
  6. Draw Conclusions
   1. State and Check 
   Assumptions
   There are three requirements for 
     hypothesis testing to work
     –Assumptions about the population
     –Assumptions about the sample
   Assumptions about the 
   Population
   “Assumption of Normality” - the 
    population is normally distributed or the 
    sample size is sufficiently large so that 
    the CLT comes into play and