incomplete counterbalancing
an experimental design that controls for order effects by using a limited number of possible sequences of treatments administered in such a way that each treatment appears equally often in each position. For instance, the following arrangement of sequences of three treatments (A, B, C), each assigned to a different subgroup of participants, demonstrates incomplete counterbalancing: A-B-C to Subgroup 1, B-C-A to Subgroup 2, and C-A-B to Subgroup 3. Compare complete counterbalancing. See also Latin square.