Definitions.-An arrangement of v objects (called treatments) in b sets 4 w+ J" E% i: g1 s(called blocks) will be called a pairwise balanced design of index unity and type h8 ~4 B$ P8 T3 S, r
(v; ki, k2, .. ., ki) if each block contains either k1, k2, .. ., or km treatments which& a. n6 Q* g$ ^6 F& G3 M
are all distinct (k, < v, k, $ kj), and every pair of distinct treatments occurs exactly' c/ W% m: r3 X, J$ R! L5 q
in one block of the design. If the number of blocks containing k, treatments is 7 E, A( [) K: @7 y* Tb,, then clearly b = A bi, v(v-1) = i biki(k -1)。。。 - t5 c+ \1 ?9 {/ |) N $ A! m( z* V$ \9 s5 S- z谁能帮我解释一下,可以举个简单的例子。。谢谢!~( B" ]- X- v: d3 l7 o' G* D, {