Chemical reaction comprehension on triple levels of chemical concepts representations

Eden izmed namenov raziskovalcev v znanstveni disciplini kemijskega izobraževanja je popularizacija izsledkov raziskav med študenti, bodočimi učitelji kemije. S seznanjanjem specialnih didaktikov za poučevanje kemije na univerzitetni ravni ter učiteljev kemije za področje osnovnošolskega in srednješolskega izobraževanja o izsledkih raziskave pa tudi z njihovim prenosom v izobraževalni proces bomo prispevali k uspešnejšemu izobraževanju na področju kemije. Raziskovalci na področju kemijskega izobraževanja velik del raziskovalnega interesa namenjajo preučevanju razumevanja trojne narave kemijskih pojmov v povezavi z vizualizacijo in drugimi merami, ki še vplivajo na usvajanje kakovostnega znanja kemijskih vsebin – brez razvoja napačnih razumevanj. Na osnovi relevantnih teoretičnih izhodišč je bil oblikovan raziskovalni problem, ki je postavljal vprašanje o pojmovnem razumevanju kemijskih reakcij na treh ravneh predstavitev kemijskih pojmov. Osnovni namen raziskave je bil ugotoviti, katere strategije reševanja kontekstualnih problemov s področja kemijskih reakcij uporabljajo študentje študijskega programa dvopredmetni učitelj, smer kemija, in kako se v teh strategijah reševanja problemov razlikujejo študentje v različnih letnikih študija. Strategija reševanja kemijskega problema je bila zaradi kompleksnosti pojma definirana kot uporaba ekspertne oziroma neekspertne poti fiksacij usmerjene pozornosti na interesna področja pri reševanju kemijskega problema. V raziskavi je bilo preučevano tudi, kako na dosežke v znanju in uporabo ekspertne poti fiksacij pri reševanju kemijskega problema vplivajo kemijsko predznanje, vizualizacijske in intelektualne sposobnosti ter notranja motivacija. Na osnovi kvalitativne analize avdioposnetkov v kombinaciji s podatki očesnega sledilca so bila identificirana najpogostejša napačna in nepopolna razumevanja izbranih kemijskih pojmov vsebine o redoks reakcijah. S polstrukturiranimi intervjuji so bili določeni tudi morebitni vzroki za napake pri reševanju treh kemijskih problemov. Tehnika sledenja očesnim premikom je v empirični raziskavi služila za triangulacijo podatkov ter tako pripomogla k objektivnejši in zanesljivejši interpretaciji rezultatov. V raziskavo je bilo vključenih 55 študentov in študentk študijskega programa dvopredmetni učitelj, smer kemija. Rešili so preizkus predznanja in serijo testov ter izpolnili vprašalnik. Preizkus znanja, testi in vprašalnik so pri vključenem vzorcu kazali zadovoljive merske značilnosti. Pri reševanju kemijskih problemov je bilo ugotovljeno, da notranjo motivacijo za reševanje povečuje uvodni kontekst, pa tudi to, da so vsi trije kemijski problemi študentom dobro poznani, zanimivi in zastavljeni po naraščajoči težavnostni stopnji. Pri napovedovanju skupnega dosežka števila točk pri reševanju kemijskih problemov z različnimi napovedniki je statistično značilnost dosegla le uporaba ekspertne oziroma neekspertne poti fiksacij, medtem ko študentova opredelitev težavnosti oziroma zanimivosti nista dosegli statistične značilnosti. Ugotovljeno je bilo, da študentje slabše rešujejo kemijske probleme tudi zaradi manjše sposobnosti sočasnega in zato kompleksnejšega povezovanja več informacij ter slabih ali celo nepravilnih pristopov k reševanju (uporaba neekspertne poti fiksacij usmerjene pozornosti) problema. Študentje s slabšim kemijskim predznanjem, z intelektualnimi in vizualizacijskimi sposobnostmi so zahtevnejši kemijski problem reševali na makroskopski in manj na simbolni ravni. Ob tem abstraktnejše submikroskopske ravni predstavitve pri reševanju večinoma niso uporabljali. Kaže se, da je v večini primerov uporaba neekspertne poti fiksacij, ne glede na letnik študija oziroma kemijsko predznanje, vodila tudi do napačne rešitve. S slik poti in slik gostot fiksacij usmerjene pozornosti pri reševanju kemijskih problemov v skupinah študentov različnih letnikov študija je v splošnem mogoče povzeti, da so študentje 1. letnika 1. stopnje in tisti študentje, ki so kemijski problem reševali z uporabo neekspertne poti fiksacij, navodilo problemov prebrali večkrat. Število povezav med različnimi interesnimi področji kemijskega problema, ki je bil ocenjen kot težek oziroma zelo težek, je bilo večje pri študentih z dobrim kemijskim predznanjem, ki so problem reševali z uporabo ekspertne poti fiksacij. Študentje nižjih letnikov, študentje s slabim kemijskim predznanjem in študentje, ki so kemijske probleme reševali z uporabo neekspertne poti fiksacij, so, ne glede na letnik študija, med seboj v večji meri povezovali makroskopsko in simbolno raven, medtem ko so submikroskopsko raven večkrat izpustili. Študentje, ne glede na letnik študija, ki so kemijske probleme reševali z uporabo ekspertne poti fiksacij, so simbolno raven opazovali v večji meri kot študentje, ki so kemijski problem reševali po neekspertni poti fiksacij. Poleg uporabe ekspertne poti fiksacij so na opazovanje simbolne ravni v splošnem pomembno vplivali tudi ustrezno kemijsko predznanje, visoka raven formalno-logičnega mišljenja in ustrezna kapaciteta delovnega spomina. Študentje s slabim kemijskim predznanjem so pri reševanju problema večinoma uporabljali enak algoritem reševanja (reševanje z uporabo neekspertne poti fiksacij), ki je bil za njih preprost in naj bi ga precej dobro razumeli. Študentje z dobrim kemijskim predznanjem so posamezna vprašanja kemijskega problema skušali pretvoriti oziroma preoblikovati v preprosto nalogo, ki jim je dala tudi lažjo pot do rešitve. Ti študentje, ki so kemijski problem reševali z uporabo ekspertne poti fiksacij, so lažje in hitreje poiskali strategijo reševanja kemijskega problema, ki jih je v večini vodila tudi do pravilne rešitve. Pri napovedovanju uvrstitve študenta v višjo oziroma nižjo skupino glede na dosežek v znanju redoks reakcij pa tudi pri napovedovanju uporabe ekspertne poti fiksacij z napovedniki notranje motivacije, vizualizacijskih sposobnosti ter intelektualnih sposobnosti in kemijskega predznanja so raven statistične značilnosti dosegli intelektualne sposobnosti (raven formalno-logičnega mišljenja in kapaciteta delovnega spomina) in kemijsko predznanje. Notranja motivacija za učenje kemije na treh ravneh predstavitev kemijskih pojmov in vizualizacijske sposobnosti statistične značilnosti niso dosegli. Da se vizualizacijske sposobnosti pri reševanju kemijskih problemov niso izkazale za pomemben napovednik, je do določene mere mogoče razložiti s tem, da so kemijski problemi te raziskave zahtevali povezovanje najmanj osmih različnih interesnih področij na vseh treh ravneh predstavitve kemijskega pojma. Mogoče je tudi, da vizualizacijske sposobnosti sodijo le pod del splošnih kognitivnih zmožnosti, ki imajo pri razumevanju abstraktne submikroskopske ravni predstavitve sicer ključno vlogo, medtem ko kot samostojni faktor pri reševanju kompleksnih kontekstualnih kemijskih problemov na treh ravneh predstavitev nimajo večjega vpliva. Kljub vsemu boljše dosežke v znanju redoks reakcij oziroma uporabi ekspertne poti fiksacij pri reševanju tovrstnih kemijskih problemov dosežejo tisti študentje, ki so za reševanje takšnih kemijskih problemov ustrezno notranje motivirani. Pri poučevanju abstraktnih kemijskih vsebin je ključnega pomena, da učitelj za boljše razumevanje reševanja kemijskih problemov na treh ravneh predstavitev kemijskega pojma učencu oziroma dijaku nudi podporo. Usmerjati ga mora v pravilen način iskanja rešitve problema z razlago in s prikazom ekspertne poti reševanja. Učitelj mora učencu pomagati pri razvijanju spretnosti in kompetenc reševanja problemov ter spodbujati učenje z razumevanjem. Tako posameznik razvije trajno in kakovostno kemijsko znanje.One of the purposes of researchers in the scientific discipline of chemistry education is to popularise research findings among students, future chemistry teachers. By informing teachers of chemistry education at the university level and teachers of chemistry at the primary and secondary level about the results of the study and transferring the findings into the educational process, we will contribute to a more successful education in the field of chemistry. Researchers in the field of chemistry education devote much of their research interests to investigating the understanding of the triple nature of chemical concepts in connection with visualisation and other measures that further influence the acquisition of qualitative knowledge of chemical content without developing misconceptions. Based on the relevant theoretical starting points, a research problem was formulated to address the conceptual understanding of chemical reactions at three levels of representation of chemical concepts. The main purpose of the study was to determine what strategies are used by students of chemistry in the Two-Subject Teacher study programme to solve contextual problems involving chemical reactions and how students in different years of study differ in these problem-solving strategies. Due to the complexity of the concept, the strategy for solving a chemical problem was defined as the use of the expert or non-expert path of attentional fixation that focuses on areas of interest in solving a chemical problem. The study was also conducted to examine how prior chemical knowledge, visualisation, intellectual abilities, and intrinsic motivation influence the prior knowledge and the use of the expert path of fixations when solving a chemical problem. Based on a qualitative analysis of audio recordings combined with the eye-tracker data, the most common misconceptions and incomplete understandings of selected chemical concepts of content about redox reactions were identified. Semi-structured interviews were also performed to identify the possible causes of errors in solving three chemical problems. The eye movement tracking technique was used in the empirical part of the study to triangulate the data, thus contributing to a more objective and reliable interpretation of the results. Fifty-five students of the Two-Subject Teacher study programme majoring in chemistry participated in the study. They took a pre-knowledge test, a series of other tests, and completed a questionnaire. The tests and the questionnaire showed satisfactory measurement characteristics in the included sample. When solving chemical problems, it was found that the intrinsic motivation for problem-solving was increased by the introductory context, and that all three chemical problems were well known and interesting to the students and posed in the increasing order of difficulty. In predicting the total score in solving chemical problems with different predictors, statistical significance was achieved only by using the expert or non-expert fixation path, while students\u27 definition of difficulty or interestingness did not achieve statistical significance. Students were found to be less successful at solving chemical problems due in part to their lesser ability to integrate more information at the same time, and therefore having more complex, poorer or even incorrect solution approaches (using the non-expert fixation path). Students with poorer prior chemical knowledge, intellectual and visual abilities, solved a more complex chemical problem at a macroscopic rather than a symbolic level. At the same time, more abstract sub-microscopic levels of representation were mostly not used in the solution. It seems that in most cases, the use of the non-expert fixation path, regardless of year of study or prior chemical knowledge, also led to the wrong solution. From the images of the paths and the images of the fixation densities of focused attention when solving chemical problems in student groups of different year levels, it can be generally concluded that the 1st year students and the students who solved the chemical problem using the non-expert fixation path read the instructions several times. The number of connections between different areas of interest of the chemical problem that were rated as difficult or very difficult was higher among students with good chemistry knowledge, who solved the problem using the expert fixation path. Lower-year students, students with poor prior chemical knowledge, and students who solved the chemical problems using the non-expert fixation path were more likely to link the macroscopic and symbolic levels, while the sub-microscopic level was repeatedly omitted. Students, regardless of year of study, who solved chemical problems using the expert fixation path paid greater attention to the symbolic level than students who solved the chemical problem through the non-expert fixation path. In addition to using the expert fixation path, attention to the symbolic level was significantly influenced by appropriate prior chemical knowledge, high levels of formal thinking, and appropriate working memory capacity. Students with low prior chemical knowledge mostly used the same solution algorithm (using the non-expert fixation path) when solving the problem, which was simple enough for them to understand it relatively well. Students with good knowledge of chemistry tried to convert or rewrite individual points of the chemical problem into a simple task, which also led them to an easier solution path. The students who solved the chemical problem using the expert fixation path found it easier and faster to find a strategy to solve the chemical problem, which usually led them to the correct solution. In predicting the student\u27s placement into the higher or lower group according to their performance in redox reactions, as well as in predicting the use of the expert fixation path with the predictors of intrinsic motivation, visualisation skills, intellectual ability, and prior chemical knowledge, it was the intellectual ability (logical thinking and working memory capacity) and prior chemical knowledge that reached the level of statistical significance. Statistical significance was not achieved in intrinsic motivation for learning chemistry at three levels of presentation of chemical concepts and in visualisation skills. The fact that visualisation skills did not emerge as an important predictor of chemical problem solving may be explained in part by the fact that the chemical problems in this study required the integration of at least eight different areas of interest at all three levels of chemical concept representation. It is also possible that visualisation skills fall only under a set of general cognitive skills. While they play a key role for understanding the abstract sub-microscopic level of representation, they do not have a major impact on solving complex contextual chemical problems at three levels of representation if examined as an independent factor. However, better performance in redox reactions or the use of the expert path of fixation in solving such chemical problems are attained by those students who are sufficiently internally motivated to solve such chemical problems. When teaching abstract chemical content, it is crucial that the teacher supports the student at three levels of representation of the chemical concept to achieve better understanding when solving chemical problems. They must guide the student to the correct solution path by explaining and showing them the expert solution path. The teacher should help the student to develop problem-solving skills and competencies and encourage learning with understanding. In this way, the individual develops long-term and high-quality chemical knowledge