DATA:      van Dobben, ter Braak et Dirkse (1998)
DIRECTORY: \CANOCO\SAMPLES\PERMUTIO\WELCH
PROBLEM:   Testing the N.P interaction in experiment E40 by the Welch (1990) 
           method
ILLUSTRATION OF:
+ the Welch (1990) permutation test of interaction
+ permuting rows and columns of a data table by using the split-plot option
+ design-based versus model-based permutations
_______________________________________________________________________________
FILE TYPE    |  FILE NAME    |         DESCRIPTION
-------------+---------------+-------------------------------------------------
 SPECIES     | species.dta   | As Example E40 but with the plots arranged in
             |               |  a standard order per block
ENVIRONMENT  | design.dta    | As Example E40 but with the plots arranged in
             |               |  a standard order per block
 PROJECTS    | welch1.con    | permutation test of N*P interaction by permuting
             |               |  rows (P) and columns (N) by using split-plot
             |               |  permutation of whole-plots consisting of the 
             |               |  same N-level and dependent split-plots 
             |               |  consisting of the same P-level
             | welch2.con    | permutation test of N*P interaction by permuting
             |               |  rows (P) and columns (N) by using split-plot
             |               |  permutation of whole-plots consisting of the
             |               |  same P-level and dependent split-plots 
             |               |  consisting of the same N-level
-------------+---------------+-------------------------------------------------

Van Dobben, H.F., Ter Braak, C.J.F. & Dirkse, G.M. (1998) Undergrowth as
a biomonitor for deposition of nitrogen and acidity in pine forest. 
Forest Ecology and Management, in press.