The core of the procedure starts with randomly selecting one of the successful variants.This example is now compared with all other examples and called the candidate. All other examples are the reference examples.
Why should inacceptable variants not be taken as candidate? The search for importance values makes only sense if factors are considered as being important. If they were unimportant their registration, evaluation and even more their manipulation is nonsense. Because of that, the hypothesis of important factors leads to the assumption, that many more combinations of values are inacceptable and only a few combinations show acceptable results. Random combinations of values most likely show inacceptable success. This majority of inacceptable variants forms a weak basis for expectations on the relevance of factors and allows only supporting inferences.