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Second‐Order Designs in Two Stages
Author(s) -
Jensen D.R.,
Myers R.H.
Publication year - 1999
Publication title -
biometrical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 63
eISSN - 1521-4036
pISSN - 0323-3847
DOI - 10.1002/(sici)1521-4036(199912)41:8<931::aid-bimj931>3.0.co;2-k
Subject(s) - aliasing , confounding , center (category theory) , computer science , stage (stratigraphy) , design of experiments , order (exchange) , statistics , mathematics , econometrics , artificial intelligence , economics , paleontology , chemistry , finance , undersampling , biology , crystallography
This study examines the comparative information intrinsic to each stage of a two‐stage experiment. Aliasing at the first stage, possible confounding of effects between stages, and efficiency comparisons for the two stages are determined directly from the analysis. A practical advantage is that runs to be assigned prospectively to the first and second stages may be evaluated beforehand, independently of empirical data. Motivated by studies in the digestion of seafood wastes, a case study develops a central composite design in k = 3 regressors, first on augmenting a 2 3 design with center run, then on augmenting a small composite design with center run. Other augmentations are considered as well. The study concludes with some minimal augmentations to a 2 3 design with center run, so as to ensure full estimability in a second‐order model in three regressors.