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Asia-Pacific Forum on Science Learning and Teaching, Volume 7, Issue 1, Article 4 (June, 2006) Muammer ÇALIK , Alipaşa AYAS and Richard K. COLL A constructivist-based model for the teaching of dissolution of gas in a liquid
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Asia-Pacific Forum on Science Learning and Teaching, Volume 7, Issue 1, Article 4 (June, 2006) Muammer ÇALIK , Alipaşa AYAS and Richard K. COLL A constructivist-based model for the teaching of dissolution of gas in a liquid
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Introduction
Solution chemistry plays a key role for the understanding of other related topics such as solubility equilibrium, electrochemistry, and so on. Indeed, science education researchers and teachers alike are aware of the importance of solution chemistry and as a consequence a variety of studies have been conducted. Topics studied include: dissolution; the nature of solutions; solubility; energy in solution processes; effects of temperature and stirring on the dissolution of solids in liquid; conservation of mass during the dissolution process; types of solutions - unsaturated, saturated and supersaturated; vapor pressure lowering; solubility of a gas in water; the relationship between vapor pressure and boiling point; and, strategies to overcome students’ alternative conceptions for dissolution chemistry (see Çalik, Ayas & Ebenezer, 2005 and references therein). Interestingly, studies of the dissolution of a gas into a liquid are rare, although Pinarbasi and Canpolat (2003) report a number of student alternative conceptions, suggesting that this is a problematic concept for students. According to theories of learning such as constructivism, determining students’ conceptions – including their alternative conceptions, is the first step in devising teaching materials that might aid conceptual change towards the scientific conception. Clearly this on its own is not enough to overcome student alternative conceptions, since developing material resources to help overcome alternative conceptions requires understanding of more than students’ lack of content knowledge. Necessary too are: a useful learning theory; a variety of teaching materials; and, an understanding of students’ prior ideas. As might be expected, such processes take a long time, especially if teachers are unfamiliar with them. As a consequence, despite science curriculum content being replete with many problematic conceptions/topics, teachers often find it hard to justify modifying their teaching methods, particularly in light of the so-called ‘crowded-curriculum’. Given teachers’ busy schedules, any teaching methods thus need to be ‘productive’, and not take up significantly extra classroom time.
It is interesting to note that textbooks frequently contain alternative conceptions, and thus they may not necessarily help students to facilitate conceptual learning (see, e.g., Hawkes, 1996; Taber, 1995). In addition, textbooks seldom take account of students’ prior knowledge (Spilich, Vedonder, Chiesi, & Voss, 1979; Kim & Van Dusen, 1998), and are not generally prepared based on any learning theory or philosophy of teaching and learning (Niaz, 2001). However, some education researchers believe that using guide material based on sound learning theories enhances learning (see, e.g., Kurt & Akdeniz, 2002; Saka, 2001).
Why is understanding student alternative conceptions important? Two reasons are reported in the literature. First, alternative conceptions held by students interact with one another, so that these alternative conceptions bring about different new meanings for existing conceptions (Schmidt, 1997). As a consequence, when students try to learn new knowledge, this may occur in a fragmented manner if links are not made to their existing knowledge (Haidar, 1997). Second, there is ‘competition’ within student’s minds amongst scientific and alternative conceptions. Research suggests that the ‘strongest’ conception - often an alternative concept – frequently is more robust than the scientific conception (Stavy, 1991). By designing appropriate learning activities, teachers and researchers attempt to reinforce scientific conceptions at the expense of students’ alternative conceptions. However, how this is best achieved is still subject to debate (see Pfundt & Duit, 2000, and references therein).
The view of learning presented in this paper is based on constructivism (Wheatley, 1991), and sees learning as a result of the interaction between pre-existing knowledge and new knowledge. In this work we posit that alternative conceptions identified in the literature or by teachers in the classroom, need to be taken into account during the teaching-learning process. Hence, our stance is that if we can develop an activity that addresses student alternative conceptions, and that can be administered easily by teachers, we may able to encourage teachers to devise new activities for a variety of conceptions. For this reason, this paper reports on classroom use of an activity about the dissolution of a gas into liquid; based on a constructivist view of learning, and the authors classroom experiences. This activity works from the constructivist-based premise that learners’ actively construct and transform their own meanings, rather than passively acquire and accumulate knowledge transmitted to them (Driver, Asoko, Leach, Mortimer & Scott, 1994; Rezai & Katz, 2002; Vosniadou & Brewer, 1987).
Copyright (C) 2006 HKIEd APFSLT. Volume 7, Issue 1, Article 4 (June, 2006). All Rights Reserved.
