The first questionnaires (A1) were administered in 1989, and studies continued over the following seven years. The procedure for conducting the questionnaires was the same in each country and educational institution. The lecturer or teacher ran the questionnaire during class time and the completed questionnaires were returned to the Ruppin Institute for collation and coding. The overall sample characteristics for the nine questionnaire experiments reported in this book are given in table B.1.

The English text of the questionnaires is provided on the following pages. Notice that the rubric at the head of each questionnaire sheet was essentially the same, and that in every case the numerical question appeared on the first page of the questionnaire sheet, and the rubric for the verbal questionnaire was at the top of the second page.

In practice, questionnaire B2 was rather different from the others since it was designed to check whether the ordering of numerical problems and questions would seriously affect the responses.