would appreciate some help with the following problem.
While running a MANCOVA i received the following error message from SPSS: " Box's Test of quality of Covariance Matrices is not computed because there are fewer than two nonsingular cell covariance matrices". So I do not have the Box's M to check the homogeneity of variance ( using Box's at least).
Some initial trawling on the web indicates that the problem might be a DV i have that was created using the sum of three of my other DV's (i.e., overall trust was computed by summing trust A, trust B, and trust C). I dont want to exclude this variable as it is an important part of my RQ.
What are my options?