RESUMEN
This paper aims to identify differences in the justification of the selection of 3D dynamic submicroscopic-representation (SMR) of the solid and liquid states of water, as well as the freezing of water presented in selected authentic tasks. According to students' achievements in solving these tasks at different levels of education, their explanations were identified. To explain in greater detail how students attempted to solve the authentic tasks, an eye-tracking method was used to identify the differences in the total fixation durations on specific areas of interest at the specific SMRs between successful and unsuccessful students in three age groups. A total of 79 students participated in this research. The data were collected with a structured interview conducted with students when solving three authentic tasks displayed on the computer screen. The tasks comprise text (as problem and questions), macro-images (photos of the phenomena) and SMRs of the phenomena. The eye-tracker was also used to measure the students' gaze fixations at the particular area of interest. The results show that successful students' justifications for a correct SMR include macroscopic and sub-microscopic representations of the chosen concepts. Along different stages of education, the selection success increases and sufficient justifications comprise the sub-microscopic level. It could be concluded that there are mostly no significant differences between successful and unsuccessful students within the same age group in the total fixation duration at the correct SMR. Further studies are needed to investigate the information-processing strategies between high and low achievers in solving various authentic tasks comprising SMRs and those that integrate all three levels of the representation of chemical concepts.
RESUMEN
The main purpose of this study was to identify understanding of atmospheric pollution phenomena such as acid rain, global warming, ozone layer depletion and photochemical smog among grade 9 lower secondary school students (aged 14 to15), in all Slovenian regions. The research involves the development of a three-tier multiple-choice diagnostic test entitled the Atmospheric Pollution Phenomena Diagnostic Test (APPDiT). APPDiT is a 15-item diagnostic test comprising items for assessing students' understanding and self-confidence of atmospheric pollution problems. The results reveal that the majority of the participants demonstrated a lack of knowledge or misconception about atmosphere pollution since the overall success rate on the APPDiT was 39.6%. In particular, only 36.7%, 5.1%, 42.7% or 19.1% of the students have adequate knowledge regarding understanding of the formation, consequences, and strategies to reduce acid rain, global warming, ozone layer depletion and photochemical smog, respectively. This shows a substantial students' knowledge deficits related to atmosphere pollution at the end of the compulsory education in Slovenia.
RESUMEN
INTRODUCTION: Poorly developed teachers' competences for managing children's allergies can pose a significant problem for the wellbeing of children in the preschool and school environment. The purpose of this study is to explore the attitudes and theoretical understanding of the management of allergic reactions in children among future teachers. METHODS: A total of 572 future teachers participated in the study, 56% of whom were in the 1st year of undergraduate educational programmes, while 44% were in the 4th year. The participants answered the Teachers' Health Competences Development - Allergy Questionnaire. RESULTS: The future teachers showed positive attitudes towards learning more about different child health issues. There was an average understanding of managing allergic reactions in children (59.4%; SD=16.1% success), with no statistically significant difference regarding the duration of education, science background or the students' self-allergy. There was, however, a statistically significant difference in achievement scores between future teachers in different educational programmes (F(3,568)=6.4, p≤.000). A subgroup of future teachers exposed to basic allergy education in the 1st year and tested again in the 4th year showed significantly better knowledge (Mann-WhitneyU=83.0; p=.008). CONCLUSION: The duration of future education, science background and self-allergy did not influence the level of knowledge regarding the management of allergic reactions in children. A basic educational programme in allergy management had a positive effect on future teachers' knowledge of managing allergic reactions in children. Our study indicates that all future teachers should be included in specific educational programmes in order to develop adequate health competences.
RESUMEN
When learning chemistry, students encounter various visualizations introducing scientific concepts and processes unobservable to the naked eye. It is often assumed that these visualizations support students' understanding and enable them to solve problems more efficiently. The research presented here investigates students' use of an explanatory key while solving tasks based on submicroscopic representations. The following features of the explanatory key were examined: 1) colored versus black-and-white, and 2) pictorial versus textual. Eye-fixation patterns and students' verbal explanations indicated that the presence of color in the key does not influence students' task solving. However, significant differences were observed with regard to a textual versus pictorial key used in the tasks: students spent more time and fixated more frequently on the key while solving tasks using a textual key in comparison to a pictorial key. The results indicate that the type of explanatory key might play an important role in revealing students' representational competence with regard to submicroscopic representations.
RESUMEN
Different models are an indispensable part of teaching and learning chemistry for students to develop adequate mental models of solid states of matter. The aim of this study was to establish the importance of using physical models (teachers' demonstrations and students' modelling) and virtual models of solid states in the educational process for students' to acquire a better understanding of the crystal structures of substances. First year grammar school students (average age 15.4 years) participated in the study. All students were divided into three groups, depending on what sort of activity involving models was used in the chemistry teaching and learning process. The solid state of matter was taught in the first group by students' constructing physical models. In the second group virtual models were used, while the third group was taught by teachers' demonstration of physical models. Students' understanding of the solid state structures was assessed with a knowledge test after the educational strategy, whereas the knowledge retention was evaluated one month following the applications of the teaching strategies with the delayed test. The students who modelled physical models scored better on the test than did the students who used virtual models and also those who were taught the solid state of matter by the teachers' demonstration of physical models. Those students who used virtual models or modelling during chemistry learning achieved statistically the same results on the delayed test, whereas the students who were exposed to the teachers' model demonstration achieved the lowest test score. It can be concluded that students who are engaged in active learning strategies that include modelling or computer interaction using virtual models develop more adequate mental models of solid state substance structures.
