Continuousbyclass effects generate the same design columns as continuousnestingclass effects. Table 4.13 shows the construction of the X
*A
effect. The two columns for this effect are the same as the columns for the X(A)
effect in Table 4.12.
Table 4.13: Example of ContinuousbyClass Effects
Data 
I 
X 







X 
A1 
A2 
X*A1 
X*A2 

21 
1 
1 
21 
1 
0 
21 
0 

24 
1 
1 
24 
1 
0 
24 
0 

22 
1 
1 
22 
1 
0 
22 
0 

28 
2 
1 
28 
0 
1 
0 
28 

19 
2 
1 
19 
0 
1 
0 
19 

23 
2 
1 
23 
0 
1 
0 
23 
You can use continuousbyclass effects together with pure continuous effects to test for homogeneity of slopes.