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Analysing data with repeated observations on each experimental unit

Published online by Cambridge University Press:  27 March 2009

J. G. Rowell  and
D. E. Walters
J. G. Rowell
Affiliation:
Agricultural Research Council Statistics Group, Department of Applied Biology, Pembroke Street, Cambridge CB2 3DX
D. E. Walters
Affiliation:
Agricultural Research Council Statistics Group, Department of Applied Biology, Pembroke Street, Cambridge CB2 3DX
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Summary

Split-plot (or split-block) analyses are commonly applied to experimental results where several successive observations of the same variable have been recorded on each experimental unit. The assumptions required for such analyses receive scant attention and it often seems unlikely that these assumptions would be satisfied in experimental situations. Five sets of results are presented to support this proposition. An alternative analytical approach is suggested in which contrasts over time are analysed; such a method is always valid, computationally simple, and readily interpretable, and may also be used to gauge the validity of the split-plot analysis.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 87 , Issue 2 , October 1976 , pp. 423 - 432
Copyright
Copyright © Cambridge University Press 1976

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