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Item banks are generally considered the basis of a new generation of educational measurement. In combination with specialized software, they can facilitate the computerized assembling of multiple pre-equated test forms. However, for advantages of item banks to become fully realized it is important that the item banks store a relatively large number of valid test items. In this paper, we demonstrate how the Rasch model is used for integrating new items into an existing wave optics item bank. First, we identified and applied a set of criteria for selecting 18 linking items from our initial item bank. In order to integrate 12 newly developed items, we combined the 18 linking items with the 12 newly developed ones into one test and administered this test to 106 postinstruction physics students from 4 universities in Slovenia, Croatia, and Bosnia and Herzegovina. It was determined that the 12 new items measure the same construct as items from the initial item bank. In addition, all items exhibited good item fit, item reliability was excellent and person reliability was fair. The ratio of standard deviations of linking item difficulties for the new test and existing item bank amounted to 0.89 and correlation of these difficulties amounted to 0.93 which indicated good linking precision. We could conclude that good linking precision can be obtained if linking items are chosen based on the following set of criteria: number of items, item fit, range and spacing of item difficulties, content representativeness, position in test form and interuniversity DIF contrasts.

We recorded diffraction patterns using a commercially available slit and sensor over a wide range of experimental circumstances, including near- and far-field regimes and oblique incidence at large angles. We then compared the measured patterns with theoretical intensity curves calculated via the numerical integration of formulas derived within the framework of scalar diffraction theory. Experiment and theory show particularly good agreement when the first Rayleigh–Sommerfeld (R-S) formula is used. The Kirchhoff formula, though problematic in the context of mathematical consistency, agrees with the first R-S formula, even for large incidence angles, whereas the second R-S formula differs visibly. To obtain such a good agreement, we replaced the assumption of an incident plane wave with that of a Gaussian beam and implemented geometric corrections to account for slit imperfections. These results reveal how the scope of scalar diffraction theory can be extended with a small set of auxiliary assumptions.

Earlier research has shown that students have tremendous difficulties with understanding certain aspects of rolling without slipping, such as the zero-velocity at the contact point and plausibility of application of the law of conservation of mechanical energy despite action of the friction force. The aim of this research was to explore whether using analogies and reasoning about extreme cases can facilitate conceptualization of the above-mentioned phenomena. A pre-test – post-test quasi-experiment has been conducted, with 93 students in the control group (CG) and 91 students in the experimental group (EG). Whereas control group students received conventional teaching, in the experimental group rolling of a cylinder has been considered as a special case of a tumbling prism for which the number of prism surfaces tended to infinity. The results of analysis of covariance showed that students from the experimental group significantly outperformed their peers from the control group on the Rolling Motion Concept Test (RMCT). Between-group differences were greater on test items that required higher level of cognitive transfer. This research suggests that using analogies and extreme case reasoning can facilitate comprehension of certain seemingly counterintuitive aspects of rolling motion. Keywords: analogy-based teaching, energy conservation, extreme case reasoning, misconceptions, rolling motion.

With the increasing availability of single- board computers equipped with fast analog-to- digital converters based on field-programmable gate arrays (FPGA), researchers and educators gain access to relatively inexpensive hardware that can be programmed for advanced coincidence counting. We demonstrate this capability by developing software for a dual-channel open- source data acquisition platform, enabling it to perform energy- and time-resolved coincidence counting and testing our system using an 241Am source. Measuring the coincidence between alpha and gamma radiation allowed us to determine the half-life of the 237Np excited state. The obtained value of 67.7 ± 0.1 ns is compatible with the value cited in the literature. Furthermore, the use of digital signal processing enabled us to sort time- resolved counts by alpha and gamma energy, which resulted in additional information on the decay scheme. Correlation heatmaps between the two spectra were plotted and used to verify the decay scheme. The half-lives of the other features visible in the gamma spectrum were determined as well.

In this paper, we are going to show how learning about some counterintuitive aspects of rolling motion can be facilitated by combining the use of analogies with extreme case reasoning. Specifically, the intuitively comprehensible examples of "rolling" polygonal prisms are used as an analogical anchor that is supposed to help the students to develop conceptual understanding about counter intuitive aspects of rolling motion.

This work is aimed at exploring some pedagogical opportunities of using photographs in physics instruction. In our study, the photography has been used for eliciting and probing students’ ideas regarding the physics of fluids in noninertial frames of reference and under conditions of equilibrium. The study involved a heterogeneous sample of 235 secondary school students, 41 physics students, and 48 physics teachers. They were presented with a photograph of a wine glass filled with liquid whose surface appeared inclined. The students were asked to comment on the reality of the phenomenon captured in the photograph, and the teachers were asked to predict the students’ responses. The results showed that about half of the students had a complete or partially complete understanding of the physical ideas and that their practical and conceptual knowledge was not dependent on their education level or curriculum followed. Most of the respondents found the task interesting and relevant. The results indicate that the teachers’ expectations regarding students’ understanding of physics often significantly depart from reality. We suggest that physics teachers include some photography-based problems and discussions in their classes. This could encourage a broad participation of students with different levels of abilities.

In this work we describe the development of the kinetic molecular theory of liquids (KMTL) concept inventory, as well as its use in investigating students' conceptual understanding of the KMTL within the contexts of aggregate states, evaporation, boiling, condensation, conduction, convection, diffusion, and surface tension. We implemented think-alouds to prepare distractors for the closed-ended version of the KMTL, which was administered to two groups of respondents: non- physicists and physicists (166 students in total from the Universities of Rijeka and Split, Croatia). From the think-alouds and results of written survey research we drew conclusions about the students' understanding of the structure of matter, thermal internal energy, entropy, temperature, and pressure. Our study not only reiterates earlier findings on students' ideas about the KMTL, it also reveals numerous additional misconceptions that had not been reported earlier. Psychometric analyses support a formative use of the KMTL inventory. The inventory questions may be extensively used for identifying misconceptions, as well as for stimulating classroom discussions and conceptual change.

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.

In this research we asked the fourth year students (N = 50) of a technical faculty of the University of Split (Republic of Croatia) to solve a partially specified physics problem related to gravitational force. The task for the students was to decide whether the situation described in the problem is feasible or not. Nevertheless, the formulation of the problem is such that it does not give students any explicit advice regarding what to calculate or how to judge the feasibility of the given situation in the real world. The research was carried out using a structured written exam method. The worksheet was structured in order to assess explicitly a few elements of the students' problem-solving performance. Based on their results, the examinees were classified into four categories, depending on what they could or could not accomplish during problem solving. A majority of students were not able to solve the given physical problem completely. A selection of students' and professors' observations is also included. Our results show that traditionally formulated numerical exercises, which are mostly used in physics teaching, do not develop students' abilities in higher-order thinking (i.e. planning, decision making or result evaluation) to a desirable extent. We suggest that partially specified problems should be given to students, both in problem-solving sessions and exams, in order to prepare them for dealing with ill-structured tasks in real life.

Many physics curricula are opened with the study of kinematics, because such practice is considered to be a logically grounded way for introducing the students with fundamental concepts and methods of pyhsics. Consequently, the approach to teaching kinematics significantly influences not only the students' knowledge of kinematics, but also their learning of other areas of physics, as well as their attitudes towards physics instruction, in general. It is theoretically supposed that understanding of kinematics can be fostered by providing the students with external visualizations, as well as with the opportunity to take measurements of physical quantities. In our study, we aimed to compare the impact of simulations, sequences of simulation frames and conventional static diagrams on students' learning performance in one-dimensional kinematics. Our student sample consisted of three classes of middle years students (N=63 ; mostly 15 year olds). Each of these classes has been assigned to one of the experimental treatments, whereby the treatment variable reflected the use of the abovementioned media types. In order to answer our research question, we conducted a pre- post quasi- experiment with three comparison groups. The results of the ANCOVA showed that students who learned from simulations or from printed sequences of simulation frames significantly outperformed their peers who learned one-dimensional kinematics from conventional static diagrams. Thereby, the results of our study indicate that learning from sequences of simulation frames seems to be particularly productive for girls. Finally, the data from our attitude survey suggest that students are very motivated for learning from simulations or sequences of simulation frames and they consider them as a very useful tool that considerably helped them to learn the difficult kinematical concepts.

We calculate the magnetic fields of cylindrical coils due to a surface current and a volume current and compare our theoretical results to measured magnetic fields of two coil types: single-layer solenoid and cylindrical thick coil by a simple experimental apparatus. Good agreement is found with the theoretical results.

Priprema za izvođenje nastavne jedinice dio je nastavnog kurikula. Pojmovi koji se navode u okviru glavnih sastavnica pripremanja nastavne teme (npr. očekivana postignuća i ishodi) pa tako i u okviru sastavnica suvremenog kurikula, nisu usklađeni u hrvatskoj pedagoškoj literaturi ni u službenim dokumentima koji se koriste u odgojno- obrazovnom sustavu. U radu se navodi jedan od načina na koji ih možemo formulirati te se daje primjer pripreme za izvođenje konkretne nastavne jedinice iz fizike.

We investigated the students’ ability to translate the velocity-time graph into a real physical situation and the possible sources of conceptual difficulties. The study involved the sample of n=324 high-school/university students, and physics teachers in Croatia. The students were presented the original non-traditional open-ended graph problem. Their written answers were classified and used to form a closed-ended prediction questionnaire for teachers. Comparing the teachers’ expectations with the actual students’ responses, we found out that teachers significantly overestimate students’ understanding. Our results also show that the observed difficulties are common in all groups of participants and that they do not depend significantly on the educational level and curriculum. We also found that the physics textbooks are also potential sources of difficulties, giving unfinished or incomplete statements regarding the sign of physical quantities in kinematic expressions. We feel that non-traditional graph problems of this kind could help teachers in establishing an active learning process in the classroom to become aware of students’ way of thinking and to overcome the difficulties., Ispitivali smo učeničke i studentske sposobnosti prevođenja grafičkog prikaza vremenske promjene brzine u realnu fizikalnu situaciju i moguće izvore konceptualnih poteškoća. Istraživanjem je obuhvaćen uzorak od n = 324 srednjoškolska učenika, studenta fizike i srednjoškolska nastavnika fizike iz Republike Hrvatske. Učenicima i studentima zadali smoo originalan netradicionalni grafički problem s pitanjima otvorenog tipa. Njihove pisane odgovore smo klasificirali i na temelju odgovora sastavili upitnik predviđanja zatvorenog tipa za nastavnike. Uspoređujući odgovore koje nastavnici unaprijed očekuju od učenika sa stvarnim odgovorima učenika uočili smo da nastavnici značajno precjenjuju učeničko razumijevanje. Naši rezultati također pokazuju da su opažene poteškoće zajedničke za sve skupine ispitanika i da ne ovise u značajnijoj mjeri o stupnju obrazovanja i kurikulu. Ustanovili smo da hrvatski udžbenici također predstavljaju mogući izvor poteškoća jer sadrže nedorečene i necjelovite tvrdnje koje se odnose na predznake fizičkih veličina u kinematičkim jednadžbama. Smatramo da netradicionalni grafički problemi tog tipa potiču aktivan proces učenja i nastavnicima omogućuju prilagodbu učeničkom načinu razmišljanja s ciljem svladavanja opaženih poteškoća.

Analizom sadržaja i ilustracija vezanih uz temu Leće u udžbenicima i zbirkama zadataka na hrvatskom jeziku, ustanovili smo da se funkcija leća, sabiranje ili rasipanje svjetlosnog snopa, pripisuje isključivo njihovom obliku i to tako da izbočena leća sabire, a udubljena rasipa svjetlosni snop. Pojednostavljivanjem sadržaja i zanemarivanjem činjenice da funkcija leća ovisi kako o obliku, tako i o optičkim sredstvima od kojih je leća i njezina okolina, izostaje učeničko razumijevanje svakodnevnih pojava tumačenih pomoću primjene leće te se otvara prostor za stvaranje miskoncepcija. Stoga je nužno, prilikom pojednostavljivanja tumačenja znanstvenih činjenica, kako u literaturi, a tako i u nastavnom procesu, koristiti ispravne znanstvene činjenice na odgovarajućoj razini. U ovom radu ponudili smo metodičku obradu teme Leće, koja se može prilagoditi za različite razine obrazovanja.

In this work we analyze the wave–particle aspects of radiation in (incoherent) Compton scattering in the radiation energy range from 2–100 keV. From the calculated cross sections of the scattering from the electron (positron), hydrogen and positronium we construct the interpretation functions (IFs), where our assertion is that the Compton scattering from the free electron (positron) is an established example of the particle behavior of radiation. These IFs estimate the possibility of the interpretation of radiation in terms of waves or particles in an analogy with the analysis carried out in the coherent scattering of light. Based on these IFs we propose a new criterion for the estimation of the validity of the impulse approximation (IA).

In this study we present a pilot-investigation of high-school and university students’ abilities to solve partially specified physics problem and ways which they handle the task. Students are asked to answer the question whether the given problem situation is physically possible or not in real-life without an explicit advice on what to calculate and how to judge. We used a combination of individual interview and written test methods. According to the type of the problem-solving approach the respondents were divided into the five categories. We found the majority belong to categories with preferably quantitative approach regardless of curriculum, level of education or research method. Our results indicate that standard numerical exercises, usually used in teaching, do not develop sufficiently critical thinking and real-life problem-solving abilities. We think that students could be given also partially specified problems to help them in preparing for real-life problem-solving situations. To our knowledge, this study is the first one to explore students' reactions to this type of a problem and we are motivated to continue research.

Students' reflections on the meaningfulness of physics problem statements and solutions were investigated. The sample consisted of 276 Croatian high school/university students. The students, being at the different learning levels, were all familiar with the physical concepts concerned. Students’ critical thinking processes were explored based on their responses to two open- ended ill-defined problems. Further, the teachers' ability to predict the typical students' approach to problem solving was investigated. For this purpose, 48 teachers were administered the closed- ended questionnaire composed of the empirically obtained students' responses to the two ill- defined problems. The results show that ill- defined problems have the potential of eliciting a whole diversity of deep-rooted students’ ideas regarding the meaningfulness of problem statements and solutions. Further, the results indicate that the level of students' critical thinking is low regardless of their educational level and curriculum. It seems that traditional teaching does not sufficiently develop critical thinking. The teachers correctly judge the students’ ability to consider the meaningfulness of the solution but they significantly overestimate their criticism towards the problem statement. We believe this kind of problems could facilitate the teachers’ efforts directed at systematically developing the students’ critical thinking processes. Consequently, students’ coping with ill-defined problems could help them to improve their real- life competences, as well as to develop the habit of taking a critical attitude towards the statements and solutions of physics problems.