What makes an effective science lesson?
Advances in research have reformed science education in the last thirty years. There has been a transparent shift within the goals of science teaching from pupils generating a content of scientific facts to pupils gaining broader understanding of the main concepts and ideas within the field of science.
Rogness (2007) suggests that to teach science effectively, science teachers will need to have a deep understanding of fundamental science principles and adequate scientific expertise to see the trends. She continues by stating, that this deep understanding can be achieved through the ability to reduce most science concepts to simple and basic ideas. Moreover, apply these concepts to all fields of science, and have the ability to acknowledge the existence of that concept and applying these principles in our lives.
“An effective” science lesson involves the planning of activities that involve active learning, navigating complex scientific principles, dealing with students’ preconceptions and misconceptions, and creating troublesome selections on the fly (Daehler,2016). The Education Endowment Foundation has proposed seven ways to improve the teaching and learning of science:
– Draw on the ideas that pupils bring to classes
– Assist pupils to direct their own learning
– Use models and analogies to aid understanding
– Help pupils to retain and retrieve information
– Use practical work as a part of a learning sequence
– Develop scientific literacy
– Use structured feedback
Additionally, there has been a range of pedagogic approaches and teaching theories that are well known to play a significant role in planning and delivering an “effective” lesson, which incorporates inquiry approaches, constructivist approaches, practical work, creativity in science, modelling and analogies, and many others.
This assignment focuses primarily on modelling and analogies, as this has become an area of interest, in my school I observed a few science teachers using models and analogies effectively in their classroom to explain complex concepts and ideas in science. As an example, I have observed one teacher using the particle model of matter to describe the physical properties of solids, liquids and gases. At the end of the lesson, students were able to explain the differences between gases, liquids and solids, in terms of compressibility, fluidity, and the space between particles.
Arabatzis and Ioannidou (2015) imply that models and analogies are closely interlinked: every so often models are based on analogies and analogies have a huge role to play in modelling practices, though analogies must not be mixed with models. As Achinstein (1971) points out that, there is clearly a fundamental difference between a model and an analogy. He identifies analogy as the relationship between two physical systems or entities, whereas a model is usually developed and created on the basis of an analogy. Despite this, most models outgrow the analogy from which they originated.
Models
Gilbert and Boulter (2000) defined a model as a “representation of an idea, object, event, process or a system”. Relatedly, “models are thinking tools that encourage students to create meaningful mental representations of abstract ideas; modelling is also referred to as the essence of inquiry science” (Harrison, 2003).
According to the science strand of the Secondary National Strategy, models are classified into:
• Teaching models– they are used to describe abstract phenomena. They can be visual representations (e.g. a diagram of the eye), three-dimensional (e.g. molecular models) or computer simulations.
• Scientific models– consensus models agreed by scientists. They can be pictorial, such as the arrangement of particles in liquids, solids and gases or mathematical representations.
• Historical models– explanations employed by scientists in the past, such as Bohr and Rutherford’s mental models of the atom, and Volta and Ampere’s representations of electricity in terms of the pressure and flows of liquids.
Harrison and Treagust (2000) emphasise the importance of models in chemistry and state that “chemistry relies on models to describe and explain all its chemical and physical changes”. Chemical equations and formulae, symbolic models, mathematical, theoretical and concept process models explain important concepts, such as the atomic theory and reaction mechanisms. They continue to say, “How well could chemistry be taught without the periodic table model of element properties?”. Despite this, they claim that that no single model can sufficiently model a science concept; thus, teachers must encourage students to use multiple models as often as possible. It is important that teachers discuss model meanings with their students and frequently prompt students that all models “break down somewhere and that no model is right” (Harrison &Treagust, 1998).
Duit (1991) and Venville (1994) explicitly state that teachers must encourage pupils to critique their mental models to see where they break down with regards to scientists’ mental models. Enabling students to construct and critically analyse their own models, supports conceptual development outcomes (Abell & Roth, 1995). To promote positive attitudes and enhanced cognitive understandings, Penner (1997) suggests that students should be given the chance to link conceptual and metacognition when dealing with physical models. Moreover, model-based teaching approaches might develop a sensible view of models whenever students are able to acknowledge the application and limitations of the models and the modelling process (Taylor ,2003).
Analogies According to the science literature review, there are several definitions of analogy; many studies have identified analogies as a subset of models as they involve the comparison between two things that are similar in some respects. An analogy helps to describe the idea, thing, or process by contrasting it to something that students are more familiar with. A theory or characteristic of one term is extended to another term on the basis of such similarities and is likewise claimed as valid in that case (Jonāne ,2015). Dagher (1995) has identified analogy use in a variety of source domains such as actual/observed life experience, personalized stories, common objects and science fiction.
In a literature review on the role of analogies in science education, the benefits of analogies originate from their implication within a constructivist perspective of learning in that they are useful tools for conceptual development as they open up new perspectives. They tend to promote understanding of the abstract by recognising resemblances within the real world and provide mental image of the abstract while incite students’ interests which will have a motivational factor. In addition, they encourage teachers to consider students’ prior knowledge, which may expose alternative conceptions in areas already taught (Duit, 1991).
Glynn (1991) referred to the analog as the familiar concept, whereas the target is called the unfamiliar concept. Despite their beneficial effects, depending on the analog-target relationship, Treagust, Harrison and Venille (1998) may argue that analogies can lead to incorrect or impaired learning.
For example, if the analog is unfamiliar to the learner, development of systemic understanding is precluded. In the same way, Glynn (1989) suggests that an analogy could mislead learning entirely since an analogy is never based on a complete one-to-one match between an analog and a target. Furthermore, an analog reasoning is only possible if the students use the intended analogies. Treagust, Harrison and Venille (1998) claim that unmatched traits between the analog and the target are often a source of confusion for students to transfer unmatched attributes from the analog to the target.
Research studies have revealed that teachers use analogies spontaneously and, unsystematically (Glynn, Duit, & Thiele ,1995; Thiele & Treagust ,1994), As a result, several authors have indicated that teachers could utilize analogies effectively, if they have clear rules or guidelines for teaching with analogies.
Hence the literature has introduced three primary teaching models for effective use of analogies: Teaching-With-Analogies Model (TA) (Glynn, 1991, 1995, 1996), General Model of Analogy Teaching (GMAT) (Zeitoun, 1984) and FAR (Focus, Action, Reflection) Model (Treagust, Harrison&Venville, 1998). Following these teaching models and understanding, the benefits and the limitations of analogy use may enable teachers to use them more effectively in the classroom (Orgil &Bodner,2005). Furthermore, when teachers use a well-planned and explained analogy in class, students will be able to understand difficult concepts, organise their thinking and learn about a given topic in a meaningful way.
Vosniadou and Skopeliti (2008) have examined the roles of both models and analogies in conceptual restructuring. Their study involved investigating school children’s knowledge of counter-intuitive science text with and without the use of visual models and/or verbal analogies. The results showed significant gains for the models and analogies groups compared to the controls. They also showed that the interventions were not necessarily successful for all children but had the greatest impact on the children who were in the transition to understanding the scientific explanation and had rejected some of the presuppositions of their naive theories that constrained their understanding of the scientific explanations. In addition, the children who had a good understanding for the analogies were able to use them to restructure their physical explanations.
In summary, the generalisations about the effective use of models and analogies is not easy to make, as their use in teaching different science concepts may interact with the nature and demands of particular topics on students, their prior knowledge and experience, the teacher’s style, among other factors. However, it is important that teachers have a good pedagogical content knowledge about the nature of science, in particular the role of models and analogies in the science education. Teachers should view analogies and models as pedagogical tools that have both strengths and limitations. They are “clearly not a magic resource to promote understanding of scientific concepts but their potential can be capitalised if they are prudently used” (Ramos, 2011).
