Newcombe R G
Department of Medical Computing and Statistics, University of Wales College of Medicine, Health Park, Cardiff, UK.
Stat Med. 1996 Oct 30;15(20):2143-7. doi: 10.1002/(SICI)1097-0258(19961030)15:20<2143::AID-SIM377>3.0.CO;2-D.
Many cross-over designs with t > or = 2 treatments and periods and n = bt subjects (b an integer > or = 1) which incorporate balance for first-order carry-over effects are already known: single squares with any even value of t and some odd ones also; and sequentially balanced pairs of squares for any odd t > or = 3. We describe the construction of designs with b = 3, for t < or = 5, 7, 9, .... This permits use of sequentially balanced designs for any combination of b > 1 and t, except for b = t = 3, for which no such design exists.
许多具有t≥2种处理和时期且n = bt个受试者（b为整数≥1）的交叉设计，其中纳入了一阶残留效应的平衡，这些设计已经为人所知：t为任何偶数时的单方块设计，某些奇数t时也适用；以及对于任何奇数t≥3的顺序平衡方块对设计。我们描述了b = 3时，t≤5、7、9等情况的设计构造。这允许对b＞1和t的任何组合使用顺序平衡设计，但b = t = 3的情况除外，因为不存在这样的设计。
