Analysis of Response Surfaces 95
 Coefficient of determination 97
 Variance, standard error,and confidence
 intervals 98
 Significance of the coefficients 99
 Significance of the equation 100
 Linear versus quadratic surface 102
 A prior and a posteriori information 105
Multiple Regression--Visiographic 108



VII FARMER-MANAGED TRIALS 115

Design 116
 Check plots 117
 Number of sites 118
Analysis and Interpretation of Results 119
 Farmers' evaluation 119
 Passive evaluation 120
 Active evaluation 121
 Researchers' evaluation 125
 Modified stability analysis 126
 Distribution of confidence intervals 131
 Response surfaces using modified
 stability analysis 142


VIII INITIATING AND MANAGING FSR/E PROGRAMS 149

Getting an On-Farm Research Program Started 150
Planning and Managing On-Farm Research 151
Defining Research Regions 153
Evaluating On-Farm Research 154
Regional Interinstitutional Cooperation 156


Bibliography 159
About the Book and Authors 162