A Context-based Teaching Concept on Electric Circuits - Development and First Results

Despite the importance of electricity for today’s industrial society, students often perceive the abstract topic of electric circuits as uninteresting. In order to foster students’ interest, we developed a context-based teaching concept on simple circuits. Building on research findings on students’ interests, the concept covers the topic at the example of contexts like bumper cars, the electric eel, or the electric fence. While previous studies suggest that such a context-based approach can improve affective factors such as student interest, the evidence on the impact on students’ conceptual understanding is inconclusive. Therefore, we empirically evaluated the teaching concept in a field study with 7th and 8th graders to investigate the effects of context-based teaching on students’ conceptual understanding, while also assessing their interest and self-concept. By comparing our concept with conventional teaching in a pre-post-follow-up design, we aim to improve the current state of research regarding the effects of context-based teaching in authentic teaching environments. First analyses did not reveal significant differences between the context-based concept and conventional approaches, neither regarding the affective factors interest and self-concept nor conceptual understanding.


Motivation for the Research Project
Science education not only aims to help learners understand key scientific concepts, but also to foster their interest in science.This is of particular importance in physics which is overall considered as one of the least popular school subjects [1].One approach to spark students' interest in the subject matter are context-based resources that use real-world applications as starting points for learning.This strategy is described in literature as "applications-led" or simply "context-based" [2].Such approaches are backed by findings that not the content area (e.g., mechanics, electric circuits) primarily determines the development of students' interest, but rather the contexts in which the content is embedded [3].
Within the junior high school level physics curriculum, electric circuits certainly represent a comparatively abstract topic, and students very often do not develop an adequate conceptual understanding [4].In the EKo project (German abbreviation for "Electricity with Contexts"), we therefore developed a context-based teaching concept for a unit on simple electric circuits.This unit is usually taught in 7 th or 8 th grade.In order to facilitate the implementation of the teaching concept, we developed a textbook and additional digital resources.Each chapter of our context-based textbook focusses on a specific question (e.g., whether electric eels are dangerous for humans) along which students learn the physics of electric circuits.The idea is that contexts are not only used as examples or for illustrative purposes, but rather shape the structure for the learning of the key physical concepts of electric circuits (for example the relationship between current and voltage).Hence, this approach is also known as "context-structured" (literal translation) in the German-speaking science education discourse [5].As part of the research project, our aim is to investigate the effects of such an approach on the students' conceptual understanding, their interest, and their physics-related self-concept.
The EKo project follows a design-based research approach.This, for example, means that the design of the teaching concept is based on previous research findings and is further improved through iterative cycles that include the feedback of teachers and students.In particular, the EKo project builds on the work that was done at TU Darmstadt on contexts in the field of electricity [6].In addition, our context-based approach broadly follows the theory of Situated Learning [7] and does in particular meet several criteria for designing situated learning environments [8].Examples of such criteria are the use of authentic contexts and the use of complex situations as starting points.
The project is part of the binational project "Electricity with Potential -Electricity with Contexts" (EPo-EKo) of seven universities from Germany and Austria [9].Within this overall project, a total of three teaching concepts on electric circuits were developed and are being evaluated in collaboration with high schools in Germany and Austria.

State of Research
The integration of contexts into physics lessons has been part of the German national education guidelines since 2004 [10].However, context-based resources or textbooks usually only mention contexts or examples on single pages [6].Although previous studies have shown that context-based teaching has a positive effect on affective factors, the findings regarding students' conceptual understanding are inconsistent.This is why Taasoobshirazi and Carr [11] call for further research.They especially underline the need for well-designed studies with a pre-post-design and a control group in order to draw reliable conclusions on the effects of context-based teaching approaches.
Taasoobshirazi and Carr [11] also point out that the situation is similar in biology and chemistry.Taking chemistry as an example, a substantial number of context-based teaching concepts were developed in recent decades, with the project "Chemie im Kontext" coordinated by the IPN Kiel being among the most known approaches in Germany [12].However, as Ültay and Çalık [13] outline in their literature review on context-based teaching in chemistry, making generalizable statements on the effects of context-based learning is still difficult because the reviewed studies vary a lot in terms of quality and research methodology.In addition, Ültay and Çalık [13] report inconsistent results regarding the effect of context-based teaching on conceptual understanding in chemistry educationjust like Taasoobshirazi and Carr [11] did regarding physics education.To sum up, although some context-based teaching concepts exist in the field of science education, only very few of them have been empirically investigated in a quasi-experimental field study in an authentic teaching environment.The EKo project aims to address this research gap.

Research Objectives
The research project investigates how the use of context-based teaching resources on simple electric circuits affects … x the students' conceptual understanding, x the students' interest (including both the overall interest in physics and the interest in physics as a school subject), x and the students' physics-related self-concept.

Theory-led Development of the Teaching Concept
A core element of the development process was the identification of contexts for the individual chapters based on previous research findings on students' interests in science education, such as the findings from the IPN study [3] or the ROSE study [14].In particular, the IDa study and the corresponding work by Dopatka [6] played a key role in the development process since contexts were identified that both boys and girls find interesting in the field of electricity.The nine chapters and the contexts assigned to each chapter are summarized in Figure 1.However, this does not necessarily mean that students have personal real-world experiences with every single context [5].As suggested by the sequence of chapters, the concept as a whole follows a conventional content structure [15].This distinguishes the EKo concept from the other two teaching concepts developed as part of the EPo-EKo project [9], which follow a content structure with a focus on potential difference [16].Based on the findings from the studies mentioned above, a preliminary version of the teaching resources was developed by the research groups of the EPo-EKo project.Since a revision cycle in collaboration with schools is essential for the development of high quality teaching resources, we asked teachers from three pilot classes to teach the unit on simple electric circuits using our preliminary context-based teaching resources.Afterwards, the respective teachers were asked to provide feedback based on their hands-on experiences in the classroom.Furthermore, we conducted one-to-one interviews with students who were taught with the context-based teaching concept.Based on the feedback by students as well as teachers, we then further improved the context-based teaching concept as part of a re-design cycle.The empirical evaluation described in Section 4 is based on this final version of the teaching concept.

What happens if multiple wolves touch
the fence at the same time?

Examples
As outlined before, the contexts we selected for the context-based teaching concept do not primarily function as illustrations or simple examples.Instead, every chapter is guided by a specific applicationrelated question which forms the basis for the students' engagement with physics.Figure 2 illustrates this approach at the example of the chapter on parallel circuits: The guiding question asks for the consequences of multiple wolves touching the fence at the same time.This question provides the main thread along which the physical laws of parallel circuits are introduced.As an example of how this is implemented in the textbook, the abstract way of drawing a parallel circuit (on the right) is juxtaposed to the parallel circuit from the context (on the left).Towards the end of the chapter, students should have developed the necessary conceptual understanding to answer the guiding question.The guiding questions of the other seven chapters are listed in Figure 3.These questions are not only a key component of the textbook, but also of the additional digital resources available to teachers.

Chapter
Guiding question

1) Electric circuits
What are the components of the electric circuit in a bumper car?
2) Conductivity How can you find bones in the ground without extensive excavations?
3) Electric current Why does the rear fog-light of a car shine brighter than a normal taillight?

4) Electric voltage
Is the electric eel dangerous to humans?

5) Resistance
Without excavations, how can underground objects be accurately identified?7) Series circuits Does it make a difference for the stimulation current treatment of knees if the current is passed through both knees in series?8) Ohm's law Why does a hairdryer from Germany only generate a "gentle breeze" when plugged into a socket in the US?
Figure 3: Guiding questions of the various chapters in the teaching concept.

Implementation in Schools
Teachers who volunteered to take part in the research project were provided with the textbook and supplementary digital resources.By featuring texts, diagrams and exercises, the format of the textbook is similar to standard high school textbooks.As with other textbooks, teachers are not supposed to cover every single aspect in class.Since the concept does not provide a lesson-by-lesson plan, teachers taking part in the study are expected to plan their lessons independently based on the students' needs and the available school equipment.In particular, this means that teachers are free to use their preferred teaching methods and physics experiments in class as long as their teaching is based on the context-based teaching concept provided by us.This is because we want our context-based concept to be evaluated in a setting that is as authentic as possible.In their daily school life, teachers are usually not given detailed lesson plans or comprehensive introductions to the teaching materials either.Nonetheless, we expected teachers to follow certain guidelines.In particular, we asked them to explicitly discuss the guiding questions in class, to address the physics content along the contexts and to work on context-related exercises.In order to ensure that teachers are aware of these key ideas, the context-based teaching concept was explained and discussed with every participating teacher in oneto-one video meetings prior to its use in the classroom.However, teachers who want to use the teaching concept outside the study are also free to use individual chapters or ideas.This is possible since the underlying structure of the concept is similar to conventional approaches [15] which facilitates its integration into conventional teaching.Teachers can download the textbook and additional teaching resources from https://einfache-elehre.de (in German).This website also provides the resources related to the two other teaching concepts developed as part of the EPo-EKo project.

Empirical Data Collection
The evaluation of the context-based teaching concept is based on a quasi-experimental field study.The students are tested before the start of the unit on simple circuits (pre-test), after the unit (post-test), and ten weeks after the end of the unit (follow-up test).As shown in Figure 4, interest, self-concept and conceptual understanding are tested at all test times, whereas verbal and figural reasoning, which are assumed to be temporally stable, are only part of the pre-test.

Pre-test
Post-test Follow-up test Unit on electric circuits 10 weeks (10-15 weeks)

Pre-test
x Interest in physics (both interest in physics as a school subject and overall interest in physics) x Physics-related self-concept x 11 two-tier items on conceptual understanding x Verbal and figural reasoning

Post-and follow-up test
x Interest in physics (both interest in physics as a school subject and overall interest in physics) x Physics-related self-concept x 11 + 7 two-tier items on conceptual understanding Figure 5 illustrates the data collection plan of the EKo project.The dark shaded elements represent the two main data collection rounds within the EKo project, for which the test design is illustrated in Figure 4.The study is being carried out at junior high schools (more specifically: "Gymnasium") in the German state of Baden-Württemberg, where simple electric circuits are usually taught in the 8 th grade.In order to be able to take part in the study, teachers need to teach the unit on electric circuits twice in a row: After teaching the topic conventionally, they are required to teach the topic based on the context-based teaching concept to another class in the same grade at a later stage, for example half a year or one year later.Since the schools are spread across the state and the unit on electric circuits takes several months to complete, it was not possible to observe or to film lessons.

Test Instruments
As outlined above, a key objective of the project is to assess students' conceptual understanding.For this purpose, we use the 2T-SEC (2-Tier Simple Electric Circuit) test, which was developed as part of the EPo-EKo project [17].Designing a new test instrument became necessary since the concept of voltage in simple circuits is hardly covered by previous test instruments [18].As the name suggests, the 2T-SEC test is a two-tier test, which means that students not only have to answer a question (tier 1), but also need to justify their answer by selecting the statement that fits their reasoning best (tier 2).A sample item illustrating the two-tier structure is shown in Figure 6.
Item 9 (a) The circuit shown consists of a battery and a light bulb.The light bulb is on.

What can you say about the current in points A and B? A
The current in A is greater than in B.

B
The current in B is greater than in A.

C
The current is the same in A and B.
(b) Why? Choose the statement that best fits your reasoning.

A
The current is used up by the light bulb.

B
The current is the same in the entire circuit.

C
The current decreases with increasing distance from the battery.Apart from the exclusion of false-positive answers, a particular advantage of the two-tier approach is that the combination of answer and justification allows for the diagnosis of well-documented alternative conceptions.It should be noted that we deliberately avoided context-based items because the test instrument should not structurally disadvantage any of the groups.Instead, the test instrument focusses on the conceptual understanding of electric circuits that students are expected to develop according to the corresponding curricula.In the preliminary evaluation provided in Section 4, students' conceptual understanding is assessed based on the first 11 items of the 2T-SEC test using the "paired scoring" approach.This means that we only consider an item as solved correctly if both the answer on tier 1 and the justification on tier 2 are correct.

Example items for "interest"
strongly disagree strongly agree I like to read about physics.
Physics belongs to my favorite school subjects.
Physics helps to explain many processes in nature.
In In addition to testing students' conceptual understanding, we also assess their interest in physics and their physics-related self-concept (see Figure 7) as well as their verbal and figural reasoning ability.For this purpose, we use established test instruments: The interest scales were taken from the PISA study [19] and the IPN study [3], with a few additional items developed by Dopatka [6].The physics-related self-concept is assessed with scales from the IPN study [3].Verbal and figural reasoning are tested with two scales from the psychometrically valid Berlin Intelligence Structure Test for Adolescents [20].

Test Sample
Figure 8 shows the preliminary sample of our study at the time of writing.We expect the final sample to consist of about 600 students who were taught conventionally and about 500 students who were taught with the context-based teaching concept.All students were in grade 7 or grade 8.

Methods for Triangulation
In order to assess to what extent the teachers follow the core ideas of the context-based teaching concept, we ask them to keep a teaching diary.In this teaching diary, the participating teachers write down brief notes about the content of each lesson.This allows us to find out which parts of the context-based teaching concept were actually implemented in class.Furthermore, we ask the teachers to complete a follow-up survey after teaching the unit on simple electric circuits based on the context-based resources (see Figure 5).The purpose of these surveys is to investigate on a qualitative level where the teachers see the strengths and weaknesses of the teaching concept based on their classroom experiences.Against the backdrop of the research-practice gap, the follow-up survey also seeks to find out to what extent the context-based teaching concept has been accepted by teachers and students.As an intended redundancy to the teaching diary, teachers are asked which contexts they have actually used in class and how they would rate the individual contexts and the way the corresponding chapters are designed.Based on teachers' answers, we plan to identify criteria that context-based resources need to fulfil to be accepted by practitioners.

Preliminary Results
In this section, we provide an overview of the preliminary results regarding the development of students' conceptual understanding, interest, and physics-related self-concept.Due to the small sample of follow-up tests in the context-based teaching group at the time of writing, we only report pre-and post-test results in this article.The development of students' conceptual understanding can be obtained from Figure 9. Since more data is already available from students who were taught the unit on electric circuits conventionally, the uncertainties of the mean values are smaller.Figure 9 shows that both the conventional and the context-based approach led to a significant increase in students' conceptual understanding.However, a mixed ANOVA based on the preliminary (matched) sample reveals no statistical difference between the two approaches regarding students' increase in conceptual understanding from the pre-to the posttest (F(1, 490) = 0.00, p = 0.95, d = 0.01).The visual impression of Figure 10 suggests that the context-based teaching concept slightly increases students' interest1 and has a positive impact on students' physics-related self-concept compared to conventional instruction.However, a mixed ANOVA based on the preliminary (matched) sample shows again that the development between pre-and post-test does not differ significantly between the two groups regarding their interest (F(1, 490) = 0.02, p = 0.875, d = 0.02) or their physics-related self-concept (F(1, 489) = 0.92, p = 0.34, d = 0.10).
So far, only 5 out of approximately 20 teachers have finished teaching with the context-based teaching concept and were thus eligible to complete the qualitative follow-up survey.Hence, we can only report preliminary results.However, it is encouraging that all five teachers addressed all chapters and discussed the corresponding contexts with their classes.When it comes to their assessment of the contexts, the context "bumper car" has so far overall been rated best by the teachers, while the context "rear fog-light" was rated worst.

Discussion and Outlook
Based on the preliminary results reported above, we cannot (yet) confirm previous research findings that concept-based approaches have a positive impact on students' interest and self-concept compared to conventional approaches [2,11].Furthermore, context-based instruction does not appear to produce better results when compared to conventional instruction regarding students' conceptual understanding, which is in line with results from previous studies [2,11].
A possible explanation for these findings could be that the context-structured teaching concept is too similar to traditional teaching.Also, since we did not observe the classes ourselves, we cannot rule out the possibility that some teachers did not implement the context-structured concept as intended.Furthermore, it could be argued that while teachers are experienced in their own way of teaching, they lack familiarity with the context-based approach, which puts our teaching concept at a disadvantage.
However, due to the preliminary sample and the fact that this is only a first look at the data, more comprehensive statistical analyses are needed.For example, with regard to students' conceptual understanding, we expect more differentiated results by using more refined evaluation methods such as Rasch and multilevel analyses.By using a Rasch analysis, for example, we can directly compare the students' ability in the pre-, post-and follow-up-test, even though the post-and follow-up-test comprise seven more items compared to the pre-test (anchor test design).With the help of a multilevel analysis, we can not only control for the fact that students learn in classes and can therefore not be regarded as statistically independent, but also control for various covariates, for example their cognitive abilities.
Once we have received feedback form all participating teachers, we also plan to use the qualitative data for a re-design of the context-based teaching concept.Apart from specific improvements to our EKo teaching concept, we aim to identify general properties that context-based teaching resources need to fulfill to be most likely accepted by teachers.Drawing such conclusions is not possible yet because of the small number of teachers who have completed the follow-up survey to date.As a final step, we plan to compare the results from the EKo project with findings on the other two teaching concepts that were developed as part of the overall EPo-EKo project [9].

Figure 1 :
Figure 1: Structure of the context-based teaching concept.

Figure 2 :
Figure 2: Example of a context from the teaching concept (chapter on parallel circuits).

Figure 4 :
Figure 4: Test design of the EKo research project.

Figure 5 :
Figure 5: Data collection plan of the EKo research project.

Figure 7 :
Figure 7: Sample items on interest and self-concept (translated).

Figure 8 :
Figure 8: Sample on which preliminary results are based on.

Figure 9 :
Figure 9: Preliminary results on the development of students' conceptual understanding.The maximum score in the test was 11 points.Students received one point if both tiers were answered correctly and zero points if one or both tiers were answered incorrectly.

Figure 10 :
Figure 10: Preliminary results for the developments of students' interest and self-concept.