Next SectionBy discussing a novel paradigm, it is shown that the likeliness of an operator to trigger an intervention effect in a wh-in-situ question is determined by the logical properties of that operator (contra Beck 1996a, 2006, for instance). A new empirical generalization accounting for the differences between operators in their ability to cause intervention and improving on existing analyses is suggested. This generalization is fully predictive and allows one to not have to list in the lexicon whether an intervener (...) is problematic or not. It is implemented as a formal condition on wh-questions in a version of Hamblin 1973's/Karttunen 1977's question semantics that makes crucial use of Chierchia 2006's domain alternatives. (shrink)