Do frequency representations eliminate conjunction effects? An exercise inadversarial collaboration

The present article offers an approach to scientific debate called adversar ial collaboration. The approach requires both parties to agree on empirical tests for resolving a dispute and to conduct these tests with the help of an arbiter. In dispute were Hertwig's claims that frequency formats elimina te conjunction effects and that the conjunction effects previously reported by Kahneman and Tversky occurred because some participants interpreted the word "and" in "bank tellers and feminists" as a union operator. Hertwig pr oposed two new conjunction phrases, "and are" and "who are" that would elim inate the ambiguity. Kahneman disagreed with Hertwig's predictions for "and are" but agreed with his predictions for "who are." Mellers served as arbi ter. Frequency formats by themselves did not eliminate conjunction effects with any of the phrases, but when filler items were removed, conjunction ef fects disappeared with Hertwig's phrases. Kahneman and Hertwig offer differ ent interpretations of the findings. We discuss the benefits of adversarial collaboration over the replies and rejoinders, and present a suggested pro tocol for adversarial collaboration.