Liang and Zeger proposed a generalized estimating equations approach to the analysis of longitudinal data. Their models assume that missing observations are missing completely at random in the sense of Rubin. However, when this assumption does not hold, their analysis may yield biased results. In th
Validity of f-test in a randomized block design with missing data
β Scribed by S. P. Dash
- Publisher
- John Wiley and Sons
- Year
- 1980
- Tongue
- English
- Weight
- 396 KB
- Volume
- 22
- Category
- Article
- ISSN
- 0323-3847
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β¦ Synopsis
Abstract
In this paper the first two moments of the test criterion (Treat. S.S.)/(Treat.S.S. + Error S.S.) have been derived assuming that one observation corresponding to the first plot of the first block which is under treatment βmβ (say), is missing in a randomized block design with βVβ treatments and βrβ blocks. To keep the analysis simple the case of one missing observation has been considered. It is concluded that in general the design is not unbiased in YATES (1951) sense and the usual Fβtest is satisfactory iff /(vr β r β 1)=(S β S~1~)/(v β 1) (rβ1), the block errors are homogeneous and (vr β r β 1) is large. The analysis of three unifornity trial data indicates that the first condition is the most important for the Fβtest to be satisfactory.
However, if one observation is missing at random from some plot of some block, the Fβtest is unbiased. If the block errors are homogeneous and (vr β r β 1) GT96, the Fβtest also provides a good approximation to the corresponding randomization test in this case.
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