ANALYSIS OF A MULTIVARIATE RESPONSE RESULTING FROM OBSERVATIONS TAKENOVER TIME ON EXPERIMENTAL UNITS IN A RANDOMIZED COMPLETE BLOCK DESIGN

In assessing the effect of any treatment to control pests, the effect of the treatment over time is of as much interest as the effect immedi ately following treatment. Experiments designed to compare the effect of several treatments use time and experimental material more efficien tly by making several observations over time on each experimental unit . In studies conducted in this manner, correlations between observatio ns taken on the same experimental unit may complicate the analysis and may make consideration of time as a factor of interest in the analysi s more difficult. In this article, advantages and disadvantages of sev eral approaches for analyzing multivariate response data resulting fro m observations taken over time on experimental units in a randomized c omplete block design are discussed. Profile analysis is a multivariate technique that is restricted by fewer assumptions than many other tec hniques. Profile analysis of such multivariate response data is descri bed in detail. This technique can be used, in the context of analyzing pest management data, to compare trends in response over time with va rious treatments. An example is presented to illustrate the method.