IMPROVING STUDENTS’ CONCEPTUALISATIONS BY MANIPULATIONS IN A VIRTUAL WEB-BASED ENVIRONMENT

Abstract

Many studies have shown the trend that students’ conceptualisations of scientific phenomena are limited to the ontological category of objects. The ontological category of processes, on the other hand, is not developed enough to build valid scientific mental models (Chi , 2005; Ferrari and Chi, 1998; Vosniadou, 1991). A correct conceptualisation of any scientific concept results from a proper understanding of object properties and processes involving these objects. Moreover, Pata and Sarapuu (2003) have raised the problem that the traditional way to teach science is usually focused on the ontological category of objects. The active-learning idea, coming from constructivism, predicts that virtual manipulations improve deeper learning (Evans and Gibbons, 2007). With interactive activities, learners are the main actors of their own construction of scientific concepts. According to this approach, deeper conceptualisation will be enhanced when manipulations are possible. In the context of web-based learning, some manipulatives, which are defined as movable representations or movable objects on the computer screen (Moyer et al., 2002), can be used to create interactivity. This study investigates the students’ ontological understanding in a virtual learning environment and the effect of manipulatives on the students’ construction of ontological conceptions. More precisely, this work attempts to answer the following research questions: (1) What is the learners’ understanding about ontological category of objects comparing to ontological category of processes? (2) How do manipulatives and non-manipulatives help learners to conceptualise through ontological categories? A process-based virtual learning environment, “Cell World” (http://bio.edu.ee/models/fr/), was applied by 59 French students of junior year of high school in sciences (aged 16-17). The sample consisted of students from three average level French schools. The results presented in this paper were drawn from a pilot survey using the model translation of “Cell World”. In this model, students can move each manipulative from the store (on the left of the screen) to the area of animations where non-manipulatives are (on the right of the screen). If the selected manipulative is incorrect, learners receive a feedback which instructs them to drag the correct manipulative in order to continue the translation process. If the manipulative is correct, the animation continues so that students can observe interaction processes involving directly manipulatives (e.g. interaction between tRNA and mRNA) and/or only non-manipulatives (e.g. the fixing process of ribosome onto mRNA molecule). For leading students to use the environment correctly, a worksheet containing instructions was developed. Moreover, the worksheet also consisted of ten questions to investigate students’ understanding about ontological categories of objects (four questions) and processes (six questions). The questions about processes lead students to think in term of emergent interactions between objects. Questions about objects lead students to use factual knowledge about the properties of molecules. These questions involve also either manipulatives or non-manipulatives to investigate the role of interactivity on students’ conceptions. In order to obtain results about learners’ understanding of ontological categories, students were grouped according to their results about the two categories of questions, objects and processes: 43 students out of 59 expressed a high level of objects’ understanding – they obtained at least two-third of maximum points, whereas only 29 students expressed a high level of processes’ understanding. The Wilcoxon signed-ranks test also revealed significant differences (Z=-3.803, P<0.001) between the answers of the two categories of questions (objects and processes): 45 students demonstrated better performances concerning questions about objects than about processes, 13 answered better about objects and one was equal in both categories. Thus, the results provide evidence that the ontological category of processes is significantly less constructed and understood than the objects’ category. For studying the role of manipulatives on the student’s ontological categories of objects and processes, a Wilcoxon signed-ranks test was used. The test compared questions about objects involving manipulatives and questions about non-manipulatives: 45 students obtained better results about manipulable molecules, 10 students about non-manipulable and only 4 learners performed with non-manipulable as well as manipulable molecules (Z=-3.868, P<0.001). Another Wilcoxon signed-ranks test was used to compare students’ answers about processes when manipulatives or non-manipulatives were available in theses processes: 47 students obtained better results concerning category of processes when these processes involved manipulable molecules. Seven students performed better when processes involved non-manipulable molecule and 5 learners got the same results for manipulable and non-manipulable molecules (Z=-5.070, P<0.001). Thus, the great majority of the students showed better understanding in both ontological categories – objects and processes, when manipulatives were involved. In conclusion, these outcomes confirm precedent works: the ontological category of processes is not developed enough to build valid scientific mental models. Thus, the main challenge for teaching scientific phenomena is to lead learners to think through ontological category of processes. One possibility to help students to improve understanding in both ontological categories is to introduce manipulatives at most crucial aspects of a scientific model. -