Secondary science teaching displays strong historical continuities, as evidenced both in classroom teaching (Solomon, 1998) and in textbooks and national curricula (Roberts, 1982; Östman, 1996). However, these regularities of systematic inclusion and exclusion of certain content vary between times, educational systems, and individual teachers. Depending on the systematic inclusion and exclusion of certain content, different meanings concerning the content are indirectly offered to the student (Englund, 1997; Östman, 1998). At the same time, students also encounter a variety of more or less explicit purposes during science lessons, ranging from “do the lab according to instructions”, or “set up your own experiment”, to “explain this concept or that phenomenon”. In this study, we specifically analyze how the diversity of purposes that students encounter in secondary science education may lead to different possible meanings concerning the taught content. Our research questions are: • How do purposes vary within and across lessons in two science units? • What meanings emerge from the different purposes? We video and audio recorded two science units in two different Swedish secondary schools, one in chemistry focusing on gases and solubility, and one in physics focusing on energy. The purposes of each lesson were identified through the analytic framework of Organizing purposes (Johansson & Wickman, 2011, 2018), and the potential meanings offered through these purposes were further analyzed through the two analytic frameworks of Subject foci (Östman, 1996) and Curriculum emphases (Roberts, 1982). Through the framework of subject focus, it is possible to discern different meanings concerning the relation between humans, science, and nature, whereas the framework of Curriculum emphases concerns the contexts in which the science content is framed and, thus, constitutes messages about why science should matter to the students. Our results show that most lessons contained more than one purpose and that purposes often belonged to different subject foci/curriculum emphases. Subject foci/curriculum emphases also differed across lessons during both units. In particular, we found that the two units differed concerning the frequency of different curriculum emphases and subject foci, leading to distinct, but different patterns of potential meanings for each unit. Our results demonstrate that different meanings do indeed emerge from differences in content selection in school science. We suggest, moreover, that the analytic frameworks employed in this study may be used by science teachers in their didactic analysis, concerning the relation between teaching purposes and the different potential meanings that may emerge from these.

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