DO RECALCITRANT DATA PRODUCE ONLY NOISE - REPLY

By providing three arguments Klauer (1995) attempts to demonstrate tha t the comparative evaluation study by Hasselhorn and Hager (1995) is o f no consequence, both from a scientific and a practical point of view . As is shown, none of the partly inconsistent arguments gives rise to any doubts about the message of our study: There are good reasons to be sceptical with regard to the relative effectiveness of recent progr ams for improving children's thinking as compared with customary perce ptual exercises. This statement, however, should not be misinterpreted as the assertion that the programs are not effective, since this ques tion has not been investigated in our study.