The reading states that the difference between content knowledge and pedagogical content knowledge is an extremely important part of what teachers need to learn to be more effective. Content knowledge is merely knowing the necessary standards that are required to be taught, while pedagogical content knowledge includes information about typical difficulties that students encounter as they attempt to learn about a set of topics; typical paths students must traverse in order to achieve understanding; and sets of potential strategies for helping students overcome the difficulties that they encounter.
When teachers do not know the pedagogical content knowledge, they rely heavily on the textbook and fail to individualize and differentiate their lesson, as they do not have a deep understanding of the subject matter. An expert teacher has both pedagogical content knowledge as well as content knowledge.
The example of teaching Hamlet to a 9th grade class, illustrated the difference between the two. One teacher strictly taught the story from the content standards focusing on the importance of language in Hamlet, soliloquies, and memorization of long passages, while the other teacher made a connection to the students by asking them to imagine that their parents had recently divorced and that their mothers had taken up with a new man. This new man had replaced their father at work, and had something to do him getting fired. This demonstrates pedagogical content knowledge, as the teacher knew the story of Hamlet and was able to teach it in a manner that connected with the students.