Я тоже так поняла. А методика мне показалось обычная опросная.Предложили оценить эффект по 6-балльной шкале, потом свели в таблеице, сократив слегонца: The following data have been collected from the more than 27,000 parents who have completed our questionnaires designed tocollect such information. For the purposes of the present table, the parents responses on a six-point scale have been combined into three categories:  “made worse” (ratings 1 and 2), “no effect” (ratings 3 and 4), and “made better” (ratings 5 and 6). The “Better:Worse” columngives the number of children who “Got Better” for each one who “Got Worse.”