Should a Single Unexplained Failing Assay be Reason to Reject a Batch?
Sanford Bolton · Clinical Research and Regulatory Affairs · 1993
The problem of what to do with data that appear to be erroneous, but for which no cause is apparent, has puzzled scientists for as long as data have been collected and evaluated. These data can be characterized as outliers, not appearing to be of the same kind as other data collected under the same circumstances. One might suppose that situations exist where such outliers can be considered absurd,e.g., nobody with any knowledge of the process could conceive that such a value could exist. For example, if an automatic device for weighing individual tablets would record a zero, we would be certain that the result was not due to a weightless tablet, but rather due to some malfunction of the process. However, in the great majority of cases, the cause for an outlying result cannot be ascertained. In the case of scientific experiments for research purposes, the outlier appears among other experimental results, and the scientist can freely hypothesize reasons and explanations for its presence. Thus, the scientist can make a case for exclusion or inclusion of the outlier, and discuss reasons, implications, etc., with impunity. The future will demonstrate the correctness of his evaluation and judgement; Time will tell. 'I