A Tool for Assessing the Construction of PCK: Analysis of Coherence and Evolution through Progression Hypotheses and Pentagon Diagrams

Abstract

Over recent decades, Pedagogical Content Knowledge (PCK) has become consolidated as a central category for understanding the teaching of scientific disciplines, and has been reconceptualised as dynamic, situated and emergent knowledge in which a personal dimension is distinguished from an enacted one. Nevertheless, there is still difficulty of having analytical tools that make it possible to address, in an integrated manner, both its evolution and its internal coherence in the contexts of teacher education. In response to this gap, the present study analysed the construction, evolution and coherence of PCK in pre-service biology teachers by means of Progression Hypotheses (PH) and Pentagon Diagrams (PD) as methodological tools. Adopting a qualitative and interpretative approach, a multiple-case study was conducted with five pre-service teachers enrolled in the Biology Didactics course at a national university in Argentina, who designed teaching sequences addressed to the first years of secondary education; here, one representative case is explored in depth in order to illustrate the potential of the tools. Initial and final teaching sequences, together with semi-structured interviews conducted after each of them, were analysed, providing  access, respectively, to the knowledge mobilised during planning and the pedagogical justifications underpinning it; initial and final PCK were established by triangulating both sources. By means of a content analysis of both deductive and inductive type, five components were consolidated —purposes of teaching, selection and organisation of content, knowledge of students' prior ideas, instructional strategies, and assessment—, using PH to establish levels of increasing complexity, ranging from an academicist and transmissive perspective to one oriented towards scientific and civic literacy, and PD to visually represent the components of PCK, whose vertices are coloured according to the level attained. In the case analysed, the participant moved from an initial profile at level A in four components —only instructional strategies exceeded it— towards a final profile that reached the reference level in purposes of teaching and a level close to the reference one in the selection of content, prior ideas and strategies, whereas assessment barely exceeded the initial level. The final diagram revealed a substantial yet asynchronous reconfiguration: the incorporation of history and nature of science, socio-scientific topics and the use of simulators coexisted with reproductive assessment tasks centred on the identification of organelles. The tools thus made it possible to objectify the non-linear evolution of teacher knowledge and to reveal tensions between components, exposing fragmented profiles in transition, and to interpret assessment as a conservative core anchored in prior schooling biography. It is concluded that the articulation of PH and PD constitutes a powerful approach for assessing the coherence of PCK —similarity of progression levels across components— and identifying critical areas for situated pedagogical reflection. Its scope must nevertheless be delimited: level correspondence is a necessary but not sufficient condition for affirming relational integration between components. The diagrams hold potential as a self-regulation device that enables pre-service teachers to identify fragmentation in their own planning and to move towards a more coherent pedagogical matrix.