paired-test.md
In inferr: Inferential Statistics

output from paired sample t test is as expected when alternative is less

Code
  ifr_ts_paired_ttest(hsb, read, write, alternative = "less")
Output
                           Paired Samples Statistics                           
  ----------------------------------------------------------------------------
  Variables    Obs     Mean     Std. Err.    Std. Dev.    [95% Conf. Interval] 
  ----------------------------------------------------------------------------
     read       200    52.23     0.7249921    10.25294        50.8      53.66   
     write      200    52.775    0.6702372    9.478586       51.45       54.1    
  ----------------------------------------------------------------------------
     diff       200    -0.545    0.6283822    8.886666       -1.78       0.69    
  ----------------------------------------------------------------------------

           Paired Samples Correlations         
  -------------------------------------------
    Variables      Obs    Correlation    Sig.
   read & write    200       0.60        0 
  -------------------------------------------

            Paired Samples Test            
            -------------------            
         Ho: mean(read - write) = 0        
         Ha: mean(read - write) < 0

  ----------------------------------------
    Variables         t       df     Sig.  
  ----------------------------------------
   read - write    -0.8673    199    0.193 
  ----------------------------------------

output from paired sample t test is as expected when alternative is greater

Code
  ifr_ts_paired_ttest(hsb, read, write, alternative = "greater")
Output
                           Paired Samples Statistics                           
  ----------------------------------------------------------------------------
  Variables    Obs     Mean     Std. Err.    Std. Dev.    [95% Conf. Interval] 
  ----------------------------------------------------------------------------
     read       200    52.23     0.7249921    10.25294        50.8      53.66   
     write      200    52.775    0.6702372    9.478586       51.45       54.1    
  ----------------------------------------------------------------------------
     diff       200    -0.545    0.6283822    8.886666       -1.78       0.69    
  ----------------------------------------------------------------------------

           Paired Samples Correlations         
  -------------------------------------------
    Variables      Obs    Correlation    Sig.
   read & write    200       0.60        0 
  -------------------------------------------

            Paired Samples Test            
            -------------------            
         Ho: mean(read - write) = 0        
         Ha: mean(read - write) > 0

  ----------------------------------------
    Variables         t       df     Sig.  
  ----------------------------------------
   read - write    -0.8673    199    0.807 
  ----------------------------------------

output from paired sample t test is as expected when alternative is both

Code
  ifr_ts_paired_ttest(hsb, read, write, alternative = "both")
Output
                           Paired Samples Statistics                           
  ----------------------------------------------------------------------------
  Variables    Obs     Mean     Std. Err.    Std. Dev.    [95% Conf. Interval] 
  ----------------------------------------------------------------------------
     read       200    52.23     0.7249921    10.25294        50.8      53.66   
     write      200    52.775    0.6702372    9.478586       51.45       54.1    
  ----------------------------------------------------------------------------
     diff       200    -0.545    0.6283822    8.886666       -1.78       0.69    
  ----------------------------------------------------------------------------

           Paired Samples Correlations         
  -------------------------------------------
    Variables      Obs    Correlation    Sig.
   read & write    200       0.60        0 
  -------------------------------------------

            Paired Samples Test            
            -------------------            
         Ho: mean(read - write) = 0        
        Ha: mean(read - write) ~= 0

  ----------------------------------------
    Variables         t       df     Sig.  
  ----------------------------------------
   read - write    -0.8673    199    0.387 
  ----------------------------------------

output from paired sample t test is as expected when alternative is all

Code
  ifr_ts_paired_ttest(hsb, read, write, alternative = "all")
Output
                           Paired Samples Statistics                           
  ----------------------------------------------------------------------------
  Variables    Obs     Mean     Std. Err.    Std. Dev.    [95% Conf. Interval] 
  ----------------------------------------------------------------------------
     read       200    52.23     0.7249921    10.25294        50.8      53.66   
     write      200    52.775    0.6702372    9.478586       51.45       54.1    
  ----------------------------------------------------------------------------
     diff       200    -0.545    0.6283822    8.886666       -1.78       0.69    
  ----------------------------------------------------------------------------

           Paired Samples Correlations         
  -------------------------------------------
    Variables      Obs    Correlation    Sig.
   read & write    200       0.60        0 
  -------------------------------------------

                  Ho: mean(read - write) = mean(diff) = 0

     Ha: mean(diff) < 0      Ha: mean(diff) ~= 0       Ha: mean(diff) > 0    
         t = -0.8673              t = -0.8673              t = -0.8673       
       P < t = 0.193           P > |t| = 0.387           P > t = 0.807