Professor of Didactical Physics Ismo Koponen oversees the training of subject teachers in physics at the University of Helsinki. With a background in computational physics, he finds algorithms and programming natural methods to approach the problematics of teaching and its associated research.
Koponen and his research group have been applying mathematical models to the study of didactics for the past 15 years. Methods borrowed from network theory and quantum informatics have proven useful in analysing concept maps and texts drawn up by prospective physics teachers. Mathematical modelling has provided a vantage point over why certain topics are difficult for students and how fields of knowledge are interlinked, as well as helping to develop subject teacher training.
“Analysing students’ concept maps and assignment texts with the help of quantum informatics exposes connections left unexposed by conventional methods. This way, wider connections between conceptual elements can be analysed. In principle, the idea is similar to a generalisation of the PageRank algorithm based on the theory of quantum information, that is, the same as Google’s search algorithm,” Ismo Koponen notes.
Increasingly consistent speech
For students to understand physics, teachers should be able to use the concepts of physics consistently and without conflict.
According to Koponen, at the heart of teacher training lies the ability of students to coherently express their ideas using physics concepts, connecting them harmoniously and consistently to larger conceptual entities.
“It’s surprisingly challenging for prospective teachers, even if they are familiar with all the facts and basic concepts of physics,” Koponen says.
University Lecturer Maija Nousiainen investigated the topic in her doctoral thesis, discovering that few students were able to integrate the concepts and laws of physics into a broader conceptual whole and consistently justify the central connections.
The study found that not all students were able to consistently and simply describe, for example, how uncomplicated electric circuits behave, even though the topic is fairly central to physics in the general upper secondary school curriculum. The study helped identify ways to improve teacher training to reach this goal even better.
In fact, the aim in subject teacher training is to guide students to identify deficiencies in their argumentation and to increase the number of exercises focused on consistent argumentation.
Phenomenon-based learning can lead to the illusion of understanding
Ismo Koponen has some reservations about the functioning and success of phenomenon-based learning. While the idea is in principle good, it is questionable how it can be ensured in practice that the end result is a sufficiently complete cognitive whole comprising physics concepts and conceptual systems as well as their application according to the goals set. According to Koponen’s view and experience, there is little credence in the idea that, even on the general upper secondary school level, many students would be able to attain an in-depth understanding of and approach to excessively complex and challenging phenomena. These include climate change, and solar energy as a physical phenomenon and as part of the energy economy. All too often, attempts seem to result in incomplete learning and understanding, and even partial misunderstandings.
“Providing easy explanations for complex phenomena too often creates an illusion of learning, even though the topic has only been partially understood,” Koponen says. For phenomenon-based learning to function as desired, the conceptual and cognitive level required for learning should be identified, ensuring that the basic concepts and models set as the goals for learning and teaching can be achieved by pupils.
What does the Crookes radiometer teach?
Koponen sets on the table an object with a rotor attached to the vertical axis inside a glass bulb, composed of polished and black square vanes. The device is known as the Crookes radiometer. When the rotor is illuminated, it starts to rotate. Familiar to many from physics lessons, this is a demonstration often used to illustrate the radiation pressure caused by light. However, most physics teachers are aware that the demonstration does not prove precisely this, but rather disproves the explanation.
The phenomenon as such may not be very interesting. What is more interesting is how the acquired knowledge of physics is used to identify the correct and functional explanation of the phenomenon. Although typical teacher students, as well as general upper secondary school students who have adopted the teaching in physics effectively, are in principle proficient in all necessary basic physics (including thermodynamics, the spectrum of electromagnetic radiation, the emission and absorption of radiation), it proves challenging to identify and apply the phenomenon and the explanatory principles.
“Consistently explaining the phenomenon is not a simple task, as the response must be composed of several phenomena in a structured and coordinated manner, and this requires the establishment of an accurate and consistently progressing chain of reasoning. The phenomenon cannot be explained with any single easily described principle or law. Structures that explain complex phenomena are precisely these kinds of longer, interconnected chains of reasoning,” Koponen says.
For example, global warming as a physical phenomenon requires understanding concepts related to the emission and absorption of electromagnetic radiation and their consistent use. They are also precisely the concepts needed to understand the behaviour of the radiometer.
In other words, how can phenomenon-based learning be successful in school-level physics when understanding and explaining complex phenomena is extremely challenging even in teacher training?