Completely Randomized Designs with One Factor

• Published in: Design and Analysis of Experiments with SAS pp. 29 - 66
• Main Author: Lawson, John
• Format: Book Chapter
• Language: English
• Published: United Kingdom Chapman and Hall/CRC 2010; CRC Press LLC
• Subjects: BIOLOGY, LIFE SCIENCES; MATHEMATICS; Probability & statistics; Data Step; SAS Proc Glm; Preplanned Comparisons; Experimental Units; Non-centrality Parameter; Tukey’s HSD Method; Noncentrality Parameter; SAS Data Step; Cell Means; Normal Probability Plot; Box Cox Power Transformations; Proc Genmod; Ods Graphics; ANOVA Table; Sub-plot Factors; GLM Procedure; Source DF Square; Proc Glm Data; SAS Command; SAS Proc; SAS Power; Var Time; CRD; Treatment Factor; Proc Sort Data
• ISBN: 1420060600; 9781420060607
• DOI: 10.1201/9781439882740-6

In a completely randomized design, abbreviated as CRD, with one treatment factor, n experimental units are divided randomly into t groups. Each group is then subject to one of the unique levels or values of the treatment factor. If n = tr is a multiple of t, then each level of the factor will be applied to r unique experimental units, and there will be r replicates of each run with the same level of the treatment factor. If n is not a multiple of t, then there will be an unequal number of replicates of each factor level. All other known independent variables are held constant so that they will not bias the effects. This design should be used when there is only one factor under study and the experimental units are homogeneous.