Students’ experienced coherence between chemistry and biology in context-based secondary science education

Abstract

In current biology and chemistry secondary school practice, coherence between the subjects chemistry and biology is underexposed or even ignored. This is incongruent with the current scientific practice, in which the emphasis is shifting towards inter- and multidisciplinarity. These problems have been addressed by the development of a curriculum unit based on an authentic practice involving the eradication of Legionella pneumophila by means of copper-silver ionization. The unit operationalizes coherence between chemistry and biology in two ways, by connecting the macro-micro thinking in chemistry with the thinking in terms of levels of organization in biology and by emphasizing relations between chemical and biological concepts. The unit is developed by a design research approach. A scenario consisting of a detailed description of the intended learning and teaching process was used as a frame of reference for measuring students’ experienced coherence. The unit has been enacted at three secondary schools in the Netherlands. The results show that upper secondary, preuniversity students (grade 11, age 16–17) develop an understanding of the coherence between the domains chemistry and biology and that they are able to explicate this coherence within different interdisciplinary contexts. The developed LT strategy, based on a synthesis of macro-micro and level-of-organization thinking, proved to be successful in establishing coherence from a students’ perspective in context-based science education.