Multiple Blocking Designs
The Latin square is a plan of t rows and t columns of a square with t symbols arranged such that each letter appears once in each row and once in each column. If the symbols are Latin letters we could, as Sir Ronald A. Fisher did, call this a Latin square plan or design. If the symbols used were Greek letters, we could call the plan a Greek square. If the symbols used were Arabic symbols we could call the plan an Arabic square, and so on. By common usage this plan is used with Latin letters and is called a Latin square design. Furthermore, this design is for the removal of variations from two sources usually referred to, though not necessarily, the row and column variations. The row and column designation merely refers to the two sources.