
 Orthogonal Latin Square Designs (Site not responding. Last check: 20071022) 
  In the orthogonal version there is the additional stipulation that for each row sequence, as read from left to right, there must be a corresponding column sequence, as read from top to bottom. 
  Thus, in the present example, row 1 (A, B, C, D) is orthogonal with column 1 (A, B, C, D); row 2 (B, C, D, A) is orthogonal with column 2 (B, C, D, A); and so on. 
  The analysis of variance within an orthogonal Latin Square results in three Fratios: one for the row variable, one for the column variable, and one for the third IV whose j levels are distributed orthogonally among the cells of the rows x columns matrix. 
 departments.vassar.edu /~lowry/lsqtext.html (518 words) 
