Use of the Complementary Log-Log Function to Describe Dose-Response Relationships in Insecticide Evaluation Field Trials

Summary

Generalised linear modelling techniques are used to provide a standard method for the analysis of data from insecticide trials. The complementary log-log function provides very well-fitting dose-response curves (details to he published elsewhere). The offset facility allows a constant term to be incorporated in the model to adjust for the base level of insect attack which varies from experiment to experiment.

Each insecticide dose was replicated three times. By considering dose both as a variable and a factor the residual deviance can be partitioned into a “lack of fit” and a “pure error” term thus overcoming the problems of interpreting the absolute residual deviance which is related to the parameter value. The partitioned deviances can then be used to assess the goodness of fit of the line.