This
page will perform an analysis of covariance for four independent samples, crosstabulated according to two independent variables, A and B, where
 A_{1} and A_{2} represent two quantitative or categorical levels of the independent variable A;
 B_{1} and B_{2} represent two quantitative or categorical levels of the independent variable B;
 DV = the dependent variable of interest; and
 CV = the concomitant variable whose effects one wishes to bring under statistical control.
Procedure: For each sample, enter the paired values of CV and DV in the cells of the designated columns, beginning in the topmost cell of each column. Within any particular column, pressing the "tab" key will take you down to the next cell in the column. After all data have been entered, click the "Calculate" button. ~~ If you wish to perform another analysis with a different set of data: click the "Reset" button if the value of n for the largest of your new samples is or smaller; click the "Reload" button if the value of n for the largest of the new samples is greater than .
Data Entry:
CV = concomitant variable
DV = dependent variable_{Q}
 B_{1}

 B_{2}

CV
 DV

 CV
 DV


A_{1}

  
  
A_{2}

  
  

Dependent Variable:
Values of n for Cells and Marginals_{Q}
 B_{1}
 B_{2}

 Totals

A_{1}

  
 
A_{2}

  
 
Totals

  
 
Dependent Variable: Observed Means_{Q}
 B_{1}
 B_{2}

 Totals

A_{1}

  
 
A_{2}

  
 
Totals

  
 
Dependent Variable: Adjusted Means_{Q}
 B_{1}
 B_{2}

 Totals

A_{1}

  
 
A_{2}

  
 
Totals

  
 
Aggregate Correlation within Samples: CV vs DV_{Q}
ANCOVA Summary_{Q}
Source
 SS
 df
 MS
 F
 P

adjusted A
     
adjusted B
     
adjusted AxB
     
adjusted error
   
Test for homogeneity of regressions:_{Q}
Source
 SS
 df
 MS
 F
 P

between regressions
     
remainder
   
adjusted error
  
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©Richard Lowry 2001
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