the treatments included and need not be partitioned.
 Data for the first of the three control treatments
 (the individual farmer's own technology) would normally be
 omitted in a combined analysis of variance because it is
 somewhat different at each location. The second and third
 kinds of controls would be comparable from site to site
 and can therefore be included. In general, a format for
 an analysis of variance which combines data over sites is
 as follows:

 TABLE V-2. Combined analysis of variance procedure.

 Source d.f. S.S. M.S. F


 Site (s) s-1 SSS SSS MSS MSS
 (s-l) MS(SxT)

Blocks
within s(b-l) SSB(S) SSB(S) MSB(S) MSB(S)
sites s(b-l) MSE

Treat- t-1 SST SST MST MST
ments (t-l) MS(SxT)

Site x
treat- (s-l)(t-l) SS(SxT) SS(SxT) = MS(SxT) MS(SxT)
ment (s-1)(t-l) MSE

Error s(b-l)(t-l) SSE SSE MSE
 s(b- ) (t-1)

Total sbt-1


Combined Analysis of Variance

 The combined analysis of variance and a test for
multiple comparison of treatment means is the procedure
often chosen to evaluate technologies across a region
and/or over time. The new technologies under analysis are
very often new varieties or hybrids, but any other