Schulman Pedagogical content knowledge

Although Schulman(1986) acknowledged Dewey as one of the pre cursors of his ground breaking idea of PCK, no one has paid much attention towards the works of Dewey to find out his understanding of PCK . Lougharn(2012) claimed that each and every teacher has its own PCK, which maybe similar t or different from the PCK of other teachers. Moreover, different researchers have also identified certain important domain of PCK. Mostly it comprises knowledge of the content to be taught, teaching strategies that fit best to teach that content, student’s way of learning that content and curricular knowledge.
Not many researchers however have pointed out any kind of organized account of a teacher’s PCK. Mostly the teacher’s accounts of their PCK are in the form of raw data, needed further work to rduce the concrete account in the form ideas.
PCK does not owe its existence to Schulman’s articulation and discovery of PCK. It must be there right from the beginning. On this ground it can be said that teachers , even before the discovery of PCK, had this type of knowledge, if PCK has to qualify as an essential trait of a teacher. This amounts to saying that teachers of the past also had PCK , and not only that had their own PCK, they must also have expressed it .
Dewey being a great teacher himself and an ardent researcher and learner of educational processes and teaching, also had his notion of PCK, which he did not obviously presented under the title PCK, but must have presented in his writings. However, there are certain claims in modern research on PCK that can be utilized to confront this view that Dewey’s general reflections on method and content and cannot be subsumed under the heading of PCK.
In certain researchers it is claimed that the knowledge of pedagogical strategies that a teacher possesses is of a generic character, whereas the knowledge of content is actually of a concrete and specific nature. In other researches, this claim is contested and it is said that even the knowledge of pedagogical strategies is of a specific nature. They put forward the difficulty which a teacher faces in teaching a subject outside his or her content area. So if a math teacher, who knows his PCK well in the case of mathematics, teaches physics, he or she is certain to face difficulties finding proper strategies to teach physics.
If we grant the later view that teacher’s knowledge of pedagogical strategies is of a specific nature rather than a generic one, we, cannot deny the fact that a teacher, who in the course of time, has developed PCK in two different content areas, can somehow reflect on his or her PCK of both subjects to furnish the similarities and differences between the two. In case such an account is produced by a teacher, who has simultaneously mastered teaching of two domains of content area,  then that account can recognized as a general statement of pedagogical content knowledge.
Some people would argue that PCK of one subject is so different from that of the other that there is no possibility of drawing any similarity between the two.