There are three categories of experiments or trials, preliminary, demonstrational and critical (Steel and Torrie, 1980). Preliminary experiments are ones carried out with many treatments. They are usually conducted to focus the researcher. The most promising treatments from the preliminary trials are investigated in future critical experiments. Demonstrational trials are probably the most familiar to growers. In demonstrational trials a new plant spacing, plant type, pot type, fertilizer or other cultural method is compared to the standard practice or cultivar at the nursery. Demonstration trials are not replicated or randomized and do not offer “precise” information.Randomization and replication can change demonstrational trials into critical trials. The information a critical trial yields can be used to make accurate production system changes. Critical experiments compare treatments with sufficient observations, replications and randomization to provide “precise” and accurate information. Critical trials are what most researchers conduct at Universities, horticultural and chemical companiesare the type of experiment we conduct and analysis.