Perhaps researcher of that early period of time, who are trying to investigate teacher’s skills by students’ achievements are like that painter who is trying to sketch a portrait first time, these initial approaches were theoretically insufficient and even unreliable. Student knowledge as measured by standardized achievement tests simply did not only rest on a teacher’s tutoring. Cleverness, gender, age, nature, assertiveness, or many other individual characteristics effect students’ grades. These early researches only consider that how teachers performed when they were in classrooms. Also in this period researcher focused more on the desirable teacher’s characteristics rather than the effective and professional attitudes, that is, those activities that were related to learner knowledge. The tack was to describe clearly and exactly teaching behaviors and relate them to student understanding as calculated most often by standardized achievement test scores. In rare cases, researchers conducted experiments for the purpose of competing that certain teaching behaviors actually caused student learning. Like Kratz a century in the leading spot, these researchers assumed that “principles of effective education” would serve as new and improved standard in both process of assessment and training of instructors. Jere Brophy and Thomas Good produced the most theoretically intricate and useful reports of this work in 1986, while Marjorie Powell and Joseph Beard’s 1984 wide catalogue of research done from 1965 to 1980 is a valuable reference.