Part of logic consists in uncovering ways in which logical processes of great universality and utility are over-extended, e.g., in the misguided search for the cause of everything. It is suggested here that the search for missing premises defined as premises that make a deduction out of every argument has its own limits of sense. While often useful, it is sometimes just wrongly used by requiring that the reconstructed argument have the same categorical conclusion as the original one; and sometimes (...) inappropriately used when the argument itself does not rest upon assumptions different from itself. (shrink)
A sketch of the arguments for adding the logic of evaluation to the areas of argumentation that have been partly mapped and are worth further work by workers in rhetoric, argumentation, communication, critical thinking, and informal logic. Brief coverage of: the arguments that there cannot be any legitimate logic of evaluation; of the nature of evaluation ; and of the technical apparatus of evaluation logic.
Fallacies are the ‘ideal types of improper inference’, named only because they represent a common or seductive error. Naming them facilitates identification (reducing ‘false negatives’ in argument evaluation), but increases the risk of false positives; it is essentially a cost-effectiveness issue whether to introduce a new name. Statistical fallacies include errors of elementary experimental design, but also conceptual confusions, e.g. of cause with correlation, of association with guilt, where an illicit substitution is made. The focus here is on recent nationwide (...) efforts to replace criteria of merit with correlates of success, in the evaluation of teaching. This involves a number of mistakes, including ‘precipitate decision’, confusing the normative with the descriptive, and using minimax when optimizing or maximin is appropriate, as well as various legal and ethical blunders. (shrink)