Lesson 7: Experimental Design
|Key Learning Goals for this Lesson:|
Introduction to Experimental Design
(See Text Section 15.2)
Previously in the course, we have referenced how experiemental design drives our models and not the other way around. Therefore it is essential that statisticians understand how data are collected. Experimental design addresses how the experiment was actually conducted. This typically involves physical layout, logistics, etc., and affects the ANOVA. In our discussions of treatment designs we looked at experimental data in which there were multiple observations made for treatment applications. We referred to these loosely as ‘replicates’. In this lesson, we need to work formally with these multiple observations. This brings us to the right hand side of the schematic diagram;
The treatment design addresses the natureof the experimental factors under study. The randomization design addresses how the treatments are assigned to experimental units.