Developing the experimental skills of pre-service physics teachers

In this paper we present the focus, objectives, content and implementation of the elective course Selected Demonstration Experiments designed for physics teaching students. We map students’ personal experiences with the implementation of physics experiments in lower secondary school and high school, as well as their knowledge of the possibilities of demonstrating physical phenomena through experiments with simple tools. The continuing lack of experimentally oriented activities in physics education naturally has a negative impact on the experimental skills of physics teaching students. In this context, the prospective teacher should be able to carry out a wide range of physical experiments, demonstrations, experiments and measurements, interpret them appropriately and involve them in active perception. The lack of experimental equipment in schools for individual (or small group) student work can be at least partially overcome by the use of commonly available simple tools (plastic containers, stationery household tools, toys). Their availability is a strong motivation for individual observations, investigations and measurements at home. In the school laboratory, the teacher can easily provide such tools for frontal experiments, parallel work by groups of students or project work following observations at home. We consider and present a model of blended learning in an educational laboratory environment. In this paper we present selected ideas for physics observations and experiments with simple tools in the form of engaging video demonstrations. We have included the creation of our own educational video demonstration as a student semester project in the course presented. We present the success of achieving our learning objectives through student assessment.


Introduction
Teaching physics is demanding in terms of material and technical equipment, the use of teaching aids and didactic equipment.Recently, increased attention has naturally been paid to the use of digital technologies, the development of digital literacy and, in particular, the introduction of innovative teaching methods capable of achieving the development of students' skills.We perceive as highly effective precisely the connection between real and virtual experimentation, personal practical experience and digitally processed educational content.Combining homework in a virtual space and active cognition in a stimulating learning environment at school gives the possibility of fully exploiting the educational potential of blended learning.Our long experience with student teaching has signalled that in lower secondary and high schools, the space devoted to demonstrations, experiments and trials in which students would have the opportunity to develop a wide range of exploratory skills and competencies has declined significantly.It is therefore necessary to supplement and extend the missing personal experience and skills of experimentation, especially in student teachers [1].In this way, we will support their professional development and improve the profile of the teacher graduate.Experimentation with simple tools (such as a yoghurt cup, a straw, a paper clip, a comb...) is cost effective, implementable in school by every student, and repeatable in the home environment.
Encourages creativity, attention to detail, peer collaboration.It offers the joy of discovery, exploration and allows an individual approach to problem solving.There are ideas, videos and instructions available on the Internet for conducting experiments with simple tools.When selecting them, it is important to be aware of the safety of the implementation, the characteristics of the tools used and the details of the implementation.It is only through personal experience of carrying out 'simple' experiments that we realise how much effort and skill is needed to carry them out successfully.However, in order for an experiment to bring the necessary understanding, it is important to be able to explain it correctly, especially in relation to the knowledge already acquired.The age-appropriateness of the treatment of Internet resources is often their weakness.The user, and especially the teacher, must be able to adapt the themes for a new purpose, appropriate to his or her target group.That is why we concentrate on gaining personal experience of carrying out experiments with simple aids, creating a realistic idea of their difficulty.The virtual space with a lot of ideas, video tutorials, study materials can be a motivational tool for stimulating the learner's educational need and his interest in continuing the activities in the face-to-face classroom.We are talking about a blended learning method that we would like to implement more widely in school practice.Blended learning is an approach that combines traditional classroom teaching with online learning [2].It provides a concept of learning in which teachers and students do not have to be physically present in the same space and time.Blended learning is a model of learning that gives learners control over the learning process while facilitating collaboration with others.However, there is an art to designing what activities are best and most effective to be carried out remotely [3].Blended learning is not a one-sizefits-all approach.There are different models, each with its own unique characteristics [4].However, current physics teacher education students encounter blended learning only in their undergraduate preparation.They have not experienced it as lower secondary or high school students; they have not seen the work of a teacher.Therefore, we need to provide them with model situations close to the school environment in their professional training to give them the confidence and commitment to implement innovative teaching methods.The personal experience of pre-service teachers can be a strong motivation for introducing both teaching methods as innovative education.A great challenge for our work with pre-service student teachers is the use of a stimulating learning space and gaining initial experience of learning in such an environment.An appropriately adapted and especially equipped physics classroom is a workspace that will promote active cognition.However, to work in such an environment, the teacher needs to be prepared and intrinsically convinced that innovation will make learning more successful.

Methodology
To achieve the objectives, we use a blended learning approach for the Selected Demonstration Experiments (SDE) course.The SDE is a compulsory elective course for Master's level physics teaching students in combination with another discipline.The course has e-learning support in the LMS Moodle environment.During the 12 weeks of the semester, students are offered experimental ideas and demonstration experiments that are feasible with simple tools.Through experimentation, annotated realization, discussion of the progress and results of the experiments, they deepen their understanding of the physical principles of the demonstrated phenomena.A valuable part is the acquiring of experimental skills but also practical experience for the successful implementation of experiments.We exploit the potential of what the student can independently process in the home environment using the online space and materials we have prepared for them.There is also the advantage of time flexibility, and the possibility to choose the time and place that are most favorable for the student.It is also a strong support for an individual approach to learning but with a desired result.The basic structure of the course is based on topic-based learning (table 1) Mechanics of fluids Experimenting with water 2.
Surface layer of liquids Experimenting on the surface of liquids 3.
Structure and properties of gases Experimenting with air 4.

Geometric optics
Experimenting with rays of light 5.
Wave optics Experimenting with the colour of light 6.
Molecular physics and thermodynamics Experimenting with heat 7.
Electrical  In the course we present short overviews of selected physics problems, instructions for carrying out simple home experiments, practical advice and recommendations for the preparation of aids, short video demonstrations.The selection and implementation of an experiment in the home environment is part of the home preparation.Students are in the position of a pupil who traces simple tools, realizes the experiment, presents it to classmates.The face-to-face learning takes place in an FCL-style lab set up (figure 1) [5].We use learning zones (exchange, interact, investigate, create and present).In the faceto-face part of the class, we evaluate the processed student experiments by electronic feedback using peer assessment [6].
A key element of the teaching is the incorporation of a blended learning method using a station rotation.Students work in pairs and rotate between prepared stations as part of the exercises.Materials are prepared by the lab technician according to a shared list of experiments that are made available to the students each week.
The course has a time allocation of 1 hour of lecture and 2 hours of practice.The lecture is an interactive discussion of physical phenomena that will be explored through experiments with simple tools in a follow-up exercise.An evaluation of the students' theoretical homework is included in the lecture.In the exercises, the students present their own prepared experiments and carry out a series of measurements with the attached aids.
Comprehensively developed e-learning support for the topic of demonstration experiments with simple tools will, we believe, be part of the didactic skills portfolio of pre-service and beginning physics teachers.

Results
From the beginning, the main purpose of the SDE course was to motivate students for their future profession as physics teachers.Since the main idea of the course is experimentation with simple tools, we have chosen topics that do not follow the structure of a standard school textbook.We want to encourage the prospective teachers to think about physical phenomena in a broader context and to look for different experiments focusing on selected physical phenomena, such as experiments with air, water, etc.
The SDE course was attended by six students in the 2022/2023 academic year, which we consider a success considering that these are all students in the grade and that it is an elective course.The preparation and implementation of the blended learning assignments for the students consisted of two parts -at home and face-to-face.For a better overview, table 2 shows the activity structure of the course, which was repeated on a weekly basis.

Home
Face-to-face Remind yourself -self-study of a selected topic at high school level Brief summary of key definitions on the selected topic and feedback Experiment ideas for practice -study of experiments prepared by teachers on the selected topic

Experimentation on a given topic by rotating the stations
In the first part of blended learning, we prepared and published electronic learning materials for selfstudy at home on the LMS Moodle e-learning portal (reminders, experiment ideas for exercises, updated links to web portals with experiment ideas).The homework included the selection and planning of an experiment by the students on a specific subtopic.The students' task was to find and prepare simple resources for the nine subtopics, write and submit an electronic version of an experiment of their choice.The result is a portfolio of 54 shared experiments (6 new experiments for each subtopic) that can be used for practise and further teaching of the topic.From experience, we can say that the ideas chosen by the students were many times more imaginative and inventive than the experiment ideas taken from the original sources.To illustrate this, here are examples of experiments chosen by the students themselves The second part -the personal part -took place in the laboratory, which was divided into learning areas.
It consisted of several phases -a brief summary of the basic concepts and determination of the level of conceptual understanding of the selected physical topic by the students, conducting and presenting a home experiment (presentation zone), conducting experiments on the topics prepared by the teachers in the form of a rotation of stations (investigation zone), so that the students also became familiar with the concept of FCL.In order to provide immediate feedback to the students so that they learn to assess themselves and their classmates, but also to maintain competition and not lower the level of homework completion, the exercises included an assessment of the students.Students were assessed on two parameters -the suitability of the chosen experiment to demonstrate the physical phenomenon and the quality of the explanation in terms of promoting students' understanding.The e-voting tool (figure 3), which is directly available as a module in the LMS Moodle, was used for the assessment.

Student assessment
Mark the names of two classmates (you can evaluate yourself as well) whose physical explanation of the experiment with simple devices was given best in your opinion.

Figure 3. Example of student evaluation using the E-Voting tool in LMS Moodle
The students' final, major project was "My Semester Video" The students had the task of choosing any experiment they had conducted during the semester and preparing the materials to create an educational video.At the beginning of the semester, we familiarized the students with the video editing application InShot [9], which is easy to use and provides everything they need to create high-quality and sustainable content.We intentionally used cell phones to record and edit videos so that students could learn how to edit educational content quickly and efficiently and use this experience in their own teaching practice.The script and dubbing (table 3) explaining the physical nature of the experiment were written and the students consulted with the teachers.After consultation and editing, they created a video recording (using the school's Create Zone), which they digitally edited to use as teaching material (figure 4).

Table 3. Example of dubbing for an educational video created by a student
The thirsty candle Did you know that a burning candle drinks water?We pour water into a plate and put the candle inside.We light the candle.We cover the burning candle with a larger glass turned upside down.The candle slowly goes out.The water level in the glass gradually rises.The air in the glass warms and expands from the candle flame.At the bottom edge of the glass immersed in water, we observe the release of air.As the candle burns, the air expands and is forced out of the glass.The flame of the candle goes out due to lack of oxygen, all of which has been consumed in burning the candle.After the flame is extinguished, the air gradually cools down to room temperature.Leaked air during thermal expansion causes a decrease in the amount of air in the glass.When the air cools, a negative pressure is created in the glass, which draws water from the plate.In the final exercise, the students presented the created videos to their classmates, evaluated their work and that of their classmates, exchanged experiences with video creation, advice and suggestions for future improvements.

Conclusion
We received responses from 6 students as part of an anonymous evaluation.From the evaluation questions we select the answers to item No.When we asked what kind of improvement in the teaching of the subject they would recommend, the students only mentioned a reduction in the scope of preparation of topics for home experiments.To represent the focal concepts appearing in students' assessment responses, we developed a cloud generator using the Wordart environment (figure 5) [12].Considering the positive evaluations of the students as well as their proactive work throughout the semester, we conclude that the prepared SDE course will be suitable for deployment in the continuing education of physics teachers as part of their professional development.We are happy to convey the issues of experiments with simple devices, their physics interpretation, the use of the blended learning method as well as the work in the Future Classroom Lab (FCL) to physics teachers working in school practice.

Figure 2 .
Figure 2. Examples of a selection of student experiments Mixing colours (left) And the floating paper clip (right) [7][8]

Figure 4 .
Figure 4. Making a video (left) and a video digital processing demo (right)

4 :
In the evaluated course I would highlight as positive.Student 1: The fact that I was shown how to create very interesting physics experiments with simple tools that hide not always simple physics.How to motivate pupils with experiments that they can do on their own, even at home.Also that I have also learned to explain physics with simple experiments, I have expanded my knowledge and also acquired a very good collection of experiments that I can use in my profession as a teacher to motivate pupils, to show them that physics is all around us and that it is beautiful.And overall this subject has motivated me to become a physics teacher :) Student 2: Possibility to practically produce school experimental aids.The course is well focused on the preparation of prospective physics teachers in the sense that after the course I have a better overview of what the pupils in elementary or high school learn and how this can be better explained to them with the help of experiments made at home.Student 3: Use in teaching practice.Simplicity of aids.Student 4: The aim of the subject, the possibility of creating your own experiments using the available tools, practicality in the future teaching profession.Student 5: A simple explanation of the phenomena discussed in the exercises.Student 6: Simple experiments, interesting content, cheap and accessible tools, practical, simple.

Figure 5 .
Figure 5. Word cloud generated from students assessment