Constructing knowledge

The most popular model of how students learn is known as the constructivist model of learning. There are variants of this model, but the main features are that learning occurs in the context of pre-existing experiences and ideas, that new concepts are transformed to fit or build on those existing ideas, and that learning occurs in a social or cultural context. Learners are not empty vessels, into which new knowledge can be injected. New concepts, which are consistent with and extend pre-existing experiences and ideas, are easily and effectively assimilated. Learning is difficult, when learners have pre-existing incorrect ideas or alternative conceptions, as they must first unlearn the misconceptions in order to incorporate the new information. In a different context, it is usually much harder and more expensive to retrofit an existing house than to build from scratch. Similarly, it is very hard to overcome bad habits. A previous column in Chemistry in Australia [July 2013, page 35], noted that we simplify ideas when teaching chemistry to younger students, but warned that over-simplication often results in misconceptions that will hinder future learning. Most chemistry educators favour constructivism, because there are similarities with the process of discovery in science. Firstly, the advancement of scientific knowledge builds on past experiences and knowledge: Isaac Newton famously acknowledged, “If I have seen further it is by standing on the shoulders of giants”. Secondly, observations and data of themselves are not meaningful, until that information has been transformed to extend existing ideas: Nobel Laureate Lawrence Bragg wrote, “the important thing in science is not so much to obtain new facts as to discover new ways of thinking about them”. Science as a Human Endeavour (SHE) is one of the strands in the Australian Curriculum. Similarly, one of the learning outcomes in the Draft Chemistry Academic Standards is that graduates will be able to recognise the creative endeavour involved in the acquiring knowledge and to recognise the testable and contestable nature of chemistry. Science is practiced individually and collectively by people. Human beings, who have human virtues and fallibilities, are responsible for scientific advancements. New knowledge is constructed in the minds of learners and scientists. Just as discussions in work teams, workshops, conferences, and the scientific literature, help scientists to extend and improve scientific understanding, the important role of teachers is to guide students to refine, alter and improve their scientific understanding when extending their scientific boundaries.