We use the familiar greenhouse as t

We use the familiar greenhouse as the foundation for an experimental test bed we refer to as the greenhouse applet. The measurement unit in this study is a single tomato plant and the measured response is simply total plant biomass measured at the end of the study. The experimental treatment is a single application of nitrogen fertilizer at the start of the study. The objective of the experiment is to find the optimal dose of nitrogen fertilizer that produces maximum average biomass. With this basic experimental set-up and objective, the student is next faced with an array of decisions regarding the setting of treatments, the placement of plants in the greenhouse and whether and how blocking will be included. Finally, the student must decide when plants will be harvested.

Figure 2 shows the applet after a complete experiment (here a 4 × 4 Latin Square) has been set up, and the results obtained (the superimposed window displays a small part of the results). The different elements on the display will be discussed in the remainder of this section.