AEB 6933
 Spring 1995
 Exercise EI2


The treatments in the trial we are using reflect continuous variables
even though the treatments themselves are discreet levels and
combinations. Another way of analyzing on-farm research data, whether
the treatments reflect continuous or discreet variables, is by means
of Modified Stability Analysis (MSA).

Begin with the data exactly in the form as in the table for Exercise
FAI. That is, the treatments across the top, forming the columns and
the farms or fields (environments) forming the rows.

The procedure uses regression to estimate the response of each
treatment to environment. This response can be either linear or
curved (usually quadratic).

Use the steps in the Training Guide' and the data from the CIMMYT
maize fertilizer trial to analyze these results by MSA.























 6933/FABIEXER


 1 Hildebrand, P.E. 1993. Steps in the analysis and
 interpretation of on-farm research-extension data based on
 modified stability analysis: a training guide. Staff Paper
 SP93-11. Food and Resource Economics Department, University of
 Florida, Gainesville.