Multiphase Experiments with at Least One Later Laboratory Phase. I. Orthogonal Designs

• Published in: Journal of agricultural, biological, and environmental statistics Vol. 16; no. 3; pp. 422 - 450
• Main Authors: Brien, C.J., Harch, B.D., Correll, R.L., Bailey, R.A.
• Format: Journal Article
• Language: English
• Published: New York International Biometric Society and the American Statistical Association 01.09.2011; Springer-Verlag; American Statistical Association; International Biometric Society; Springer
• Subjects: Agriculture; Agronomy. Soil science and plant productions; Biodiversity; Biological and medical sciences; Biometrics, statistics, experimental designs, modeling, agricultural computer applications; Biostatistics; Degrees of freedom; Design analysis; Experiment design; Fundamental and applied biological sciences. Psychology; Generalities. Biometrics, experimentation. Remote sensing; Health Sciences; Mathematics and Statistics; Medicine; Monitoring/Environmental Analysis; Quadratic functions; Random allocation; Skeleton; Specimens; Statistical variance; Statistics; Statistics for Life Sciences; Tillage; Two-phase experiments; Multi-phase experiments; Experimental design; Multitiered experiments; Multiple randomizations; Laboratory experiments; Analysis of variance; Laboratory study; Variance analysis
• ISSN: 1085-7117; 1537-2693
• DOI: 10.1007/s13253-011-0060-z

The paper provides a systematic approach to designing the laboratory phase of a multiphase experiment, taking into account previous phases. General principles are outlined for experiments in which orthogonal designs can be employed. Multiphase experiments occur widely, although their multiphase nature is often not recognized. The need to randomize the material produced from the first phase in the laboratory phase is emphasized. Factor-allocation diagrams are used to depict the randomizations in a design and the use of skeleton analysis-of-variance (ANOVA) tables to evaluate their properties discussed. The methods are illustrated using a scenario and a case study. A basis for categorizing designs is suggested. This article has supplementary material online.