The agitator-study volume analyzed only texts and never observed actual audiences

Evidence

Lowenthal and Gutermann’s volume was rather like the handbook for demystifying fascist agitators which had been planned. But it was based purely on analysing texts, not on any research on the actual audience reaction. They had not even attended any agitators’ meetings, as Adorno had suggested. — Rolf Wiggershaus, The Frankfurt School, 1756