Siegfried Engelmann is the real thing, an educator who loves to teach children and knows how to do it, both personally and in his books. As far back as the late 1960s, he told the Education Establishment: you're doing it all wrong.
Engelmann takes a scientific approach. He believes you formulate programs, test them, revise them, and keep doing this until you get solutions that give you the greatest success in the ordinary classroom.