Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2034470 | Biologicals | 2009 | 8 Pages |
Abstract
Quality control for repeated bioassay runs can be performed by phase II control charts, well-known from industrial quality control. The value of interest is the potency, of which a single value per run is available. Parametric and non-parametric prediction intervals are described to estimate quality control intervals for future re-test runs. Violations against the normal distribution occur in real data frequently, particularly outliers. The non-parametric prediction intervals are limited to not too small sample sizes in both the historical and future sampling phases. Therefore, robust prediction intervals based on winsorization are proposed. R-functions for all prediction intervals are provided.
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Authors
L.A. Hothorn, D. Gerhard, M. Hofmann,