Primjena Rasch modeliranja u analizi netočnih odgovora studenata na pitanja višestrukog izbora: Primjer iz valne optike

An analysis of students’ difficulties for a curricular topic may help the educator to gain better insight into students’ reasoning about that topic which is a prerequisite for high-quality teaching. The purpose of this study was to demonstrate how distractor analysis may be used for identifying students’ difficulties in a certain topic. In order to be in position to perform invariant measurement and to easily relate students’ difficulties to their achievement levels, we decided to take a Rasch modeling approach. Our study included 14 wave optics items and 286 students from five universities in Slovenia, Croatia, and Bosnia and Herzegovina. Rasch modeling was used to estimate item and student measures, as well as to create option probability curves which allowed us to relate students’ achievement levels to the choice of individual distractors. It has been found that all 14 included items function in line with the Rasch model. In 10 out of 14 items there were distractors chosen by at least 25% of students. For several out of these 10 items, the option probability curves indicated that attractiveness of individual distractors depended on students’ ability levels. We could conclude that the Rasch-based distractor analysis may provide very useful information for differentiation of physics instruction.Analiza studentskih poteškoća vezanih za određenu nastavnu temu može pomoći predavaču u stjecanju boljeg uvida u studentsko razumijevanje određene teme, što je preduvjet za visokokvalitetnu nastavu. Svrha ovog istraživanja sastojala se u demonstriranju načina na koji analize ometača mogu biti iskorištene za identificiranje studentskih poteškoća u određenom području. Kako bismo mogli provoditi invarijantna mjerenja i lako povezati studentske poteškoće s razinama njihovih postignuća, odlučili smo se studiju provesti u okviru Rasch formalizma. Naše istraživanje obuhvatilo je 14 zadataka iz područja valne optike i 286 studenata s pet sveučilišta u Sloveniji, Hrvatskoj te Bosni i Hercegovini. Rasch modeliranje korišteno je za procjenu težine zadataka i sposobnosti studenata, kao i za kreiranje krivulja vjerojatnosti ponuđenih opcija što nam je omogućilo povezivanje razine razumijevanja studenata s izborom pojedinačnih ometača. Utvrđeno je da svih 14 zadataka funkcionira u skladu s Rasch modelom. Za 10 zadataka imali smo ometače koje je odabralo najmanje 25 % studenata. Kod nekoliko od ovih 10 zadataka krivulje vjerojatnosti ponuđenih opcija ukazuju na to da atraktivnost pojedinačnih ometača ovisi o razinama sposobnosti učenika. Možemo zaključiti da analiza ometača primjenom Rasch modeliranja može dati vrlo korisne informacije za diferencijaciju nastave fizike

Drawing and using free body diagrams: Why it may be better not to decompose forces

In this study we investigated how two different approaches to drawing free body diagrams influence the development of students’ understanding of Newton’s laws, including their ability to identify real forces. For this purpose we developed a 12-item two-tier multiple choice survey and conducted a quasiexperiment. This experiment included two groups of first-year physics students from Rijeka (RG) (n_{e}=27) and Split (SG) (n_{c}=25) Universities. Students from both groups solved mechanics problems for a period of two class hours. The only difference was that RG students used the superposition of forces approach to solving mechanics problems and in SG the decomposition of forces approach has been used. The ANCOVA (n_{c}=17, n_{e}=17) showed a statistically significant difference in favor of RG, whereby the effect sizes were moderate to large, and the largest differences have been observed in the ability of identifying real forces. Students from the control group (SG) more often exhibited the misconception that forces and their components act on a body independently and simultaneously. Our results support the idea that the practice of resolving forces into the components may not be the most effective way to develop understanding of Newton’s laws and the concept of force

Comparing different approaches to visualizing light waves: An experimental study on teaching wave optics

Research has shown that students have tremendous difficulties developing a qualitative understanding of wave optics, at all educational levels. In this study, we investigate how three different approaches to visualizing light waves affect students’ understanding of wave optics. In the first, the conventional, approach light waves are represented by sinusoidal curves. The second teaching approach includes representing light waves by a series of static images, showing the oscillating electric field vectors at characteristic, subsequent instants of time. Within the third approach phasors are used for visualizing light waves. A total of N=85 secondary school students were randomly assigned to one of the three teaching approaches, each of which lasted a period of four class hours. Students who learned with phasors and students who learned from the series of static images outperformed the students learning according to the conventional approach, i.e., they showed a much better understanding of basic wave optics, as measured by a conceptual survey administered to the students one week after the treatment. Our results suggest that visualizing light waves with phasors or oscillating electric field vectors is a promising approach to developing a deeper understanding of wave optics for students enrolled in conceptual level physics courses

Development of the kinetic molecular theory of gases concept inventory: Preliminary results on university students' misconceptions

In this study, we investigated students' understanding of concepts related to the microscopic model of gas. We thoroughly reviewed the relevant literature and conducted think-alouds with students by asking them to answer open-ended questions about kinetic- molecular theory of gases. Thereafter, we transformed the open-ended questions into multiple-choice questions, whereby distractors were based on the results of the think-alouds. Thus, we obtained a set of 22 questions which constitutes our current version of the Kinetic Molecular Theory of Gases Concept Inventory. The inventory has been administered to 250 students from different universities in Croatia, and its content validity has been investigated trough physics teacher surveys. The results of our study not only corroborate the existence of some already known student misconceptions, but also reveal new insights about a great spectrum of students' misconceptions that had not been reported in earlier research (e.g. misconceptions about intermolecular potential energy and molecular velocity distribution). Moreover, we identified similar distribution of students' responses accross the surveyed student groups, despite the fact that they had been enrolled in different curricular environments

University students\u27 conceptual understanding of microscopic models of electrical and thermal conduction in solids

Teaching the concepts of electrical and thermal transport in solids begins in elementary school through simple macroscopic models and progressively develops to microscopic quantum models within specialized university courses. Educational research has pointed to a number of misconceptions in this field, especially when it comes to understanding related phenomena at the microscopic level. This study aimed to design an appropriate open-ended version of the concept inventory to test the level of students\u27 understanding of microscopic models of electrical and thermal conduction in solids (METCS). The METCS concept inventory consists of 27 open-ended questions that examine the understanding of different and interrelated concepts. We used it as a tool for conducting interviews on a sample of ten students from the universities of Rijeka and Split (Croatia). The results of our research confirmed some previously discovered students\u27 misconceptions and revealed a wide range of new ones. These results can be used to stimulate student discussions and to design curricula and lecture plans for more efficient teaching of transport phenomena in solids. The obtained spectrum of misconceptions will serve as a reference tool for the development of a multiple-choice conceptual METCS test to allow research on larger sample

Causes of the Shortage of Physics Teachers in Croatia

Knowing the causes of the shortage of physics teachers in primary and secondary schools is necessary for the development of effective educational policies because the shortage of physics teachers is a global and persistent problem with negative consequences for the quality of education, but also for the survival of the physics profession as a whole. The aim of this study was to investigate, for the first time, the opinions of Croatian physics teachers on the causes of the deficit in their profession. For this purpose, we conducted a descriptive cross-sectional study using an online survey with Likert-type items and a constructed response item. A total of 390 respondents from all over Croatia participated in the survey, which is 29% of the total population of Croatian physics teachers in the 2022/2023 school year. According to their opinion, the causes of the shortage of Croatian physics teachers are related to the following: lack of incentives and support from the relevant institutions and bodies, the inadequacy of physics content in the curricula, the lack of motivation and negative attitude of students towards physics, impeded professional development, unequal opportunities, and challenges such as excessive workload. The results obtained provide a concrete basis for the development of an effective policy to solve the problem of the physics teacher shortage in Croatia and beyond by governments, universities, and schools

Measuring students’ conceptual understanding of wave optics: A Rasch modeling approach

Even graduate physics students have many misconceptions about basic wave optics phenomena. This suggests that there is much room for improvement of the traditional wave optics curriculum. An effective way for initiating a curriculum change is to reconsider and revise the expected learning outcomes and corresponding assessment instruments. By systematically enriching our wave optics instruction and assessment with conceptual tasks, we may increase the probability of students actively engaging in learning the conceptual aspects of wave optics. In this paper, we present the process of developing an item bank for measuring understanding of wave optics in typical introductory physics courses at universities. Thereby, the Rasch modeling approach has been used. The development of the item bank has been guided by results from multiple expert and student surveys, as well as from group interviews and think aloud interviews. Altogether 65 multiple-choice items with a single correct answer and three distractors have been prepared for field testing. Until now, 35 out of 65 items have been field tested by means of a paper and pencil survey which included 188 participants from five universities in Bosnia and Herzegovina, Croatia, and Slovenia. The field test showed that 32 out of 35 items have good psychometric characteristics and that they may be very useful for uncovering students’ misconceptions in wave optics