The aim of this researching is to expose that if there is any important difference between the knowledges about the methods and technics of teaching belong to the teachers attended to the in service education and are responsable of teaching knowledge of science lesson before and after the activity of applied seminar. It has been asked 10 open ended questions to the 43 teachers who are on duty in the city center of Tekirdağ, about their methods and technics before the seminar (preliminary test), and then it has been asked the same questions at the end of the seminar (final test) and finally it has been researched that if the knowledges of teachers changed according to their seniorities. The data which has been obtained from the researching was evaluated with the analysis of content. At the end of the evaluation of the data; it has been identified that the teachers had used mostly the technics of question-answer, straight expression and experiment. As a result, it can be declared that the teachers who have the greater seniority professionaly have less perception according to juniors relating to the methods and technics of teaching. Furthermore, it has been observed that the knowledges of the teachers relating to the methods and technics of education has been increased considerably.