EN
Education value added is a concept which has its roots in economics, and, nowadays, is also connected with students' achievement evaluation. It counterbalances the traditional arithmetic mean, which, as Dolata [2007: 5] writes, for the first time, probably “appeared in the mid 70s as a critical continuation of the idea of school accountability.” It means “an increase of the value of goods as a result of the manufacturing process” [Lisiecka, 2006: 3]; in the educational environment, therefore, education value added will be a tool of education policy [Dolata, 2007] indicating students' gain in knowledge resulting from a particular educational process, as a consequence of which it will “measure students' progress made in a specified research period” [Lisiecka, 2006: 3]. It provides information about the effectiveness of the educational process “to a large extent freed from the influence of factors being beyond the school control” [Dolata, 2006: 10] although we cannot forget that education contents may have “common features determined by a training program and individual characteristics, personality derivatives, experience, personal knowledge and original cognitive patterns created by the student” [Niemierko, 2006: 20].