This comparative case study examines the relationship between substantive content knowledge (SCK) of science concepts and inquiry-based teaching of those concepts through fine-grained analysis of the science teaching practice of three elementary student teachers in their final year of teacher preparation carried out within an elementary professional development school program (a partnership between a major northeastern university and a neighboring school district), resulting in numerous similarities in teaching context among the three participants.

I examined four elements for each participant followed by cross-case analysis: (1) specific problematic content knowledge-related teaching events that arose during inquiry-based teaching of concepts of sound and light; (2) their level of knowledge of those concepts examined in terms of depth, interconnectedness, organization and understanding of importance of underlying concepts; (3) their individual classroom inquiry style (CIS) described in terms of eight emergent aspects and representing consistencies over multiple lessons in the way each participant implemented classroom inquiry for teaching science concepts; and (4) their orientations toward teaching science (OTS).

Key findings indicate (1) the majority of problematic events exhibited by each participant involved choosing and implementing important learning goals; (2) using emergent aspects of CIS to analyze teaching allowed differentiation among the three participants' very similar inquiry-based teaching; (3) patterns of clustering of aspects revealed interrelationships among them; (4) limitations in SCK could account for all of the observed problematic events, however CIS provided alternative and often more plausible explanations, contradicting current literature ascribing limitations in conversationally risky practice to limitations in SCK; (5) Certain aspects of CIS were more consistently associated with SCK, while other aspects were more closely linked to participants' OTS.

Implications of the study include: (1) the importance of including emergent aspects of CIS when analyzing inquiry-based teaching; (2) CIS as a new level to include when investigating the relationship between SCK and inquiry-based teaching practice; (3) the value of CIS as a tool for developing individual trajectories for enhancing preservice and inservice elementary teachers' inquiry-based teaching; and (4) the need for specialized content courses for preservice and inservice elementary teachers integrating content learning, curricular vision and general science teaching strategies.