Πολλές έρευνες έχουν δείξει ότι οι μαθητές δυσκολεύονται να κατανοήσουν την έννοια της ύλης και τις φυσικές μεταβολές της. Θεωρούμε ότι οι δυσκολίες αυτές οφείλονται στο γεγονός ότι έχουν διαμορφώσει αρχικές ερμηνείες για την ύλη που διαφέρουν από τις αντίστοιχες επιστημονικές. Το πρότυπο του μικρόκοσμου είναι ένα πολύτιμο εργαλείο για την κατανόηση των εννοιών αυτών και την ερμηνεία των μακροσκοπικών φαινομένων. Στο παρόν σενάριο εφαρμόζουμε μια διδακτική παρέμβαση που σκοπό έχει να βοηθήσει τους μαθητές να μεταβούν από τις βασιζόμενες στις αισθήσεις αντιλήψεις τους για την ύλη στις πιο αφηρημένες έννοιες της επιστημονικής θεωρίας, αξιοποιώντας μια σειρά από πόρους, συμπεριλαμβανομένου και του εκπαιδευτικού προτύπου του μικροκόσμου. Βασικό στοιχείο του σεναρίου για μαθητές της Ε’ Δημοτικού είναι ότι λαμβάνει υπόψη του τις αντιλήψεις των μαθητών για την ύλη, ενώ η εισαγωγή της σωματιδιακής θεωρίας γίνεται με τη βοήθεια προσομοιώσεων του μοντέλου του μικρόκοσμου. Επίσης, αξιοποιούνται όλοι οι διαθέσιμοι υλικοί και ψηφιακοί πόροι συνθέτοντας ένα εκπαιδευτικό ψηφιακό σενάριο που βασίζεται στην επιστημονική/εκπαιδευτική μεθοδολογία με διερεύνηση. Η εφαρμογή του σεναρίου έδειξε ότι επηρέασε θετικά τις αντιλήψεις των μαθητών για την ύλη, υποστηρίζοντας και την άποψη ότι η μικροσκοπική προσέγγιση της ύλης τους βοηθά να προσεγγίσουν καλύτερα τις μακροσκοπικές έννοιες.
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Many studies have shown that students face considerable difficulties in understanding the concept of matter and its physical changes. For example, they consider that air is not a physical body and that has no weight, they consider matter continuous, particle ideas appear later, but often are not in accordance with the scientific ones etc. We believe that these difficulties are due to the fact that students form initial explanations of matter that differ from the corresponding scientific ones. According to the framework theory proposed by Vosniadou and her colleagues and based on relevant studies (Vosniadou & Brewer, 1992, 1994; Vosniadou & Mason, 2012; Vosniadou, Vamvakousi & Skopeliti, 2008), students find it difficult to understand some concepts because they violate principles of their naive theories, which are formed by their everyday experiences. These naïve theories have internal consistency and provide explanations for the phenomena, but differ significantly from the corresponding scientific ones. This is the reason why they can be an obstacle in the process of learning. When students are exposed to the scientific explanations, they try to incorporate the new information into their own explanatory frameworks, but this incompatibility can lead to inconsistency or misunderstanding. The understanding of the scientific concepts requires the reconstruction of students' ideas. The model of microcosm is a valuable tool for understanding these concepts and interpreting the macroscopic phenomena. The particulate theory of matter is one of the most important modern theories, providing accurate explanations for matter and phenomena. However, even high school students have misunderstandings about the nature of particles. For example, many students do not understand particles as the basic components of matter, but as something within matter, they see them as embedded in the material (Andersson, 1990; Lee et al., 1993; Nussbaum, 1985). This is a strong misconception that is usually reinforced by the naive realism of the students that leads them to assume that things are as they appear to be. Another difficulty for students is their commitment at the macroscopic level and at the macroscopic properties of material bodies: solids and liquids that are visible and tangible form the ontological category of matter, while gases are something else, usually more closely related to heat and electricity than with matter (Carey, 1991).Another factor that influences the process of learning is students' epistemic beliefs, namely their beliefs, about how knowledge is constructed and evaluated, about the process of knowing. Several studies have shown that students’ epistemic beliefs are related to the conceptual change in physics (Stathopoulou & Vosniadou, 2007), because only students with high-level epistemic beliefs achieved a profound understanding of the concepts of physics. In this scenario we apply a didactic intervention designed to promote the process of conceptual change for matter, i.e. to help students move from their based-on-the senses perceptions of matter to the more abstract concepts of the scientific theory, utilizing a variety of resources, both material and digital, including the educational model of microcosm. A basic element of the scenario is that it takes into consideration students' perceptions of matter and the obstacles posed by their limitations, while the introduction of the particulate theory of matter is attempted by appropriate simulations. All the available material and digital resources are best harnessed by compiling an educational digital scenario based on the scientific / educational methodology by inquiry. Therefore the scenario incorporates tasks dealing with less obvious cases of matter (e.g. invisible objects), other ways of perception of matter (e.g. special tools, simulations), analogies introducing the idea of particulate nature of matter, etc. The scenario also takes into consideration that most elementary school students do not have the necessary epistemological knowledge to combine what they perceive with their senses (e.g. solids and liquids seem to be continuous) with some of the basic principles of particle theory (matter consists of particles, etc.). That is why the scenario includes tasks that will help students overcome their belief that "things are as they appear to be" and tasks related to the uncertainty of knowledge. With regard to the model of microcosm, the scenario incorporates appropriate simulations adapted to the cognitive, deductive and synthetic abilities of students, but without over-simplifications that usually create more misunderstandings. These simulations were created in the Laboratory of Sciences, Technology and Environment of the University of Athens (Kalkanis, 2013; http://microkosmos.uoa.gr/gr/software/prosomoioseis.htm) and take into account students' misconceptions so that they do not reinforce them, therefore black background is used and particles are in constant motion. Previous attempts to exploit the model of microcosm (Papageorgiou & Johnson, 2005; Yezierski & Birk, 2006; Papageorgiou et al., 2010; Gikopoulou R. & Vosniadou S. 2012; Gikopoulou 2013) showed that even students of primary schools are able to exploit this model for the interpretation of macroscopic phenomena. Concerning the methodology, the scenario is structured on the basis of the scientific / educational methodology by inquiry, which is a pedagogical approach to the historically recognized scientific research method (Kalkanis, 2007). From a pedagogical point of view, this approach presents a comparative advantage to other traditional methods as it contributes substantially to the development of strong cognitive, metacognostic, communicative and scientific skills (Hu et al., 2008; Sun et al., 2014). Several studies highlight that Information and Communication Technologies are effective teaching and learning tools that enhance the introduction of the scientific inquiry (Papadakis, 2016; Kalogiannakis 2017). This methodology consists of five steps: a) trigger of interest, b) hypotheses (about the causes of the phenomenon being studied), c) experimentation, d) conclusions (based on the experimentation) and e) applications, explanations. The proposed scenario exploits a variety of material and digital resources by attempting a systematic effort to avoid limiting the student to simple passive observing situations. In particular, it involves performing real experiments with simple materials, but also exploiting many digital resources such as: interactive whiteboard, instructional texts, static images, animations, word clouds, conceptual maps, educational videos, videos with successive enlargements of objects, analogies for the introduction of the idea of the particulate nature of matter, simulations of microcosm etc. Students work on the basis of the worksheets created for the scenario and there are also the corresponding (completed) worksheets for the teacher. The scenario is designed for primary school students of 5th grade and its implementation includes three activities for 2 hours each, covering all the steps of the scientific / educational methodology utilizing all the above-mentioned material and digital resources. Students divided into groups of 3-4 work in the computer lab, where the interactive whiteboard is. The practical implementation of the scenario to 16 pupils of the 5th grade (10-11 years old) showed that it affected positively both students' perceptions of matter and their epistemic beliefs (Gikopoulou, 2017), supporting the view that the microscopic approach of matter helps students approach the macroscopic concepts. Mare analytically, students began to realize that things are not always as they appear to be and begin to accept the idea of the invisible particles consisting matter. They were able to distinguish material bodies from non-materials based on their properties and classify them based on their physical state in solids, liquids and gases. All students also participated with enthusiasm in the discussions and the experiments, but also in the use of the interactive whiteboard. Students’ progress is also evident in their sketches when asked to design the interior of a solid, a liquid and a gas before and after the scenario was applied. Moreover, the digital scenario increased students’ interest and their active participation in the educational process. Apart from the experiments, students liked the creation of word clouds, the videos with objects enlargement and the tools we use to "see" something (e.g. telescopes, microscopes, radar, radiographs, etc.), the analogies as well as the simulations. With regard to conceptual maps, most students said they found them very useful, especially when they returned to them to check or correct them, because they could identify their mistakes themselves. This observation is in agreement with the findings of relevant studies that suggest that conceptual maps can be used as a tool for exploring students prior knowledge, exploring students’ representations on a particular subject, conceptual change and problem solving (Gouli et al., 2006). To sum up, our results are in agreement with other researchers who argue that the use of digital tools allows children to acquire a different learning experience, highlighting their high levels of involvement, helping to promote collaboration and skills development and helping students to understand scientific concepts (Kalogiannakis and Papadakis, 2017). Educational digital scenarios can play a role as cognitive tools, support inquiry based learning situations, promote problem-solving, decision-making and critical thinking, promoting high-level cognitive skills.
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