An in-service training course in chemistry and biotechnology was organised for eighteen home economics teachers working in Finnish secondary school. The course was part of a project administered by the Finnish Board of Education in which the aims were to foster the teachers' knowledge of natural sciences and mathematics. The aim of the course was to increase the teachers' subject knowledge in chemistry and microbiology and their competence to integrate these disciplines into their home economics instruction in secondary school for pupils aged 13-16 years. The impacts of the teaching intervention on learning outcomes were assessed by self-rating inventories before and after the course and by analysing learning portfolios made by the participants. The results from quantitative data showed that the course increased teachers' subject knowledge of science and integration of that knowledge into their instruction significantly (Wilcoxon Signed Rank test and McNemar test). According to the qualitative analyses of the participants' learning portfolios, teachers experienced their learning as meaningful, effective and transferable to their own instruction. Main results of the study will be presented and their implications for improvement of home economics teachers' in-service training as well as pre-service training will be discussed.Background of the studyIn the science of home economics various phenomena, observations, and incidents are explained on the basis of both behavioural and natural sciences (Davis 1993). Due to the wide extent of the science on which it is based, the scope of the home economics curriculum (POPS 1994) in secondary school is also wide. In the Finnish home economics curriculum, practical everyday management is emphasised and is an important part of the lesson's pedagogical content; but in addition to this, the broad basis of home economics provides the teacher with opportunities also to orient pupils to science education. There are no reported data on the extent to which teachers generally integrate science into home economics in their teaching. Since the amount of natural sciences in the curriculum of home economics pre-service teacher education in Finland is minimal, we can expect their content knowledge and pedagogical content knowledge to be insufficient for this kind of approach and to be uncommon in teachers' pedagogical practices. Pedagogically, the course was based on the principles of andragogy (Knowles 1984) and social constructivism (Brown et al.1996; Ernest 1995) in which problem-based learning (Gibbs 1992), experiential learning (Miller & Boud 1996) and collaborative learning (Panitz & Panitz 1998; van Boxtel et al. 2000) are emphasised in an attempt to produce high quality learning (Simons 1999). The learning tasks and settings were planned to be meaningful, problem-oriented and contextual in such a way that they respond to real- life in the setting of home economics. Exercises, done either in pairs or in groups of four, included kitchen chemistry experiments such as making popcorn and ice cream in order to study the evaporation and freezing properties of water molecules, cheese-making to demonstrate how casein can be isolated from milk, and bread-making to demonstrate the formation of the gluten structure, and enzyme activities. Portfolios were designed not only to be evaluation tools but also as exercises through which learners explore their understanding of a topic and apply knowledge (c.f. Duffy 1999). There is some evidence that portfolio assessment, among other new assessment strategies, encourage meaningful learning and conceptual understanding, for example, in science education (Mintzes et al. 2001).