Identifying pedagogical content knowledge (PCK) in the chemistry laboratory

Abstract

This study was carried out in the chemical teaching laboratory with new graduate students while they were guided to develop pedagogical content knowledge, PCK. PCK is expertise that demonstrates a combined knowledge of pedagogy and disciplinary subject matter; since chemistry is the discipline, the abbreviation, PChK, is used. Laboratory teaching functions for student learning entail guidance of chemical techniques, and abstract chemical concepts relevant to the lab experiment, that is, chemical explanations using concepts conceived by chemists rather than perceived, e.g., atoms and chemical bonds. Instruments were built with constructivist content and attained construct validity and internal consistency to measure teaching performance. A factor analysis reduced fifteen constructs to three forms of PChK, whose names reflect the level of chemical knowledge and pedagogical sophistication required. Mentoring activities were labeled as PChK-0. PChK-1 represents procedural knowledge to manage a chemistry laboratory. PChK-2 represents devising or generating transforming explanations connected to the students. knowledge and previous experiences. A .transforming explanation. is defined as a discipline-specific illustration of how people in that discipline think about a disciplinary process, which is linked by the explanation to students. thinking about that same disciplinary-related process. PChK-3 guides students in chemistry-specific reasoning and generating transforming explanations for themselves. Examples of PChK-2 and PChK-3, using two chemical topics, are provided. [Chem. Educ. Res. Pract., 2005, 6 (2), 83-103]