Interview: Lennart Schalk

PsychED recently reviewed an article in which Lennart Schalk proposed to reverse the traditional "tell-and-practice" teaching sequence and to replace with an student-centered "trial-and-error" approach.

Today, we will look deeper into this idea thanks to an exclusive interview with the author.

PsychED: Could you tell us a little bit about yourself?

Lennart Schalk: I grew up and finished high school in Bremen, Germany. Thereafter, I moved to Berlin, Germany, and studied psychology focusing on cognitive psychology. While in Berlin I met Prof. Elsbeth Stern who was working at the Max-Planck-Institute for Human Development at that time. Nowadays, she is the professor for research on learning and instruction at the ETH Zurich, Switzerland. In obtained my PhD in educational sciences in her research group and continued to work together with her as a postdoc and a senior researcher. Currently, I hold a research professorship position for early STEM education at the PH Schwyz (Schwyz University of Teacher Education) in Switzerland. My research is situated on the intersection of cognitive psychology, instructional science, and teacher education.


PsychED: What is the source of your interest in educational psychology?

Lennart Schalk: Children grow up in a world shaped by science, technology, engineering, and mathematics (STEM). They are curious about this world, but the development of scientific-mathematical competencies and knowledge is demanding and takes a long time. How can the individual development of competences in the STEM subjects be promoted? How can curiosity and interest for STEM subjects be maintained? How do teachers use their teaching materials to give children an adequate idea of our world and the modern scientific world view? These questions guide me and my research group at the PH Schwyz in our research and development projects. We conduct empirical research in classrooms and develop and evaluate materials. Our interdisciplinary team works together with teachers to ensure the practical relevance of our projects. In this way, we aim to engineer education; that is, we want to make teaching and learning in the STEM subjects more effective and more fun.


PsychED: Your research proposes to reverse the traditional "tell-and-practice" teaching sequence and let students construct their own knowledge through trial-and-error. What is the rationale for such a revolution?

Lennart Schalk: Our research builds on the work by Manu Kapur who coined the term productive failure (2008). The main idea in reversing the traditional “tell-and-practice” teaching sequence is to first activate students’ prior knowledge before they are told how something works or can be solved. To this aim, they are confronted with interesting tasks for which they have to come up with their own solutions. Often the correct solution is out of reach for the students; that is, they fail. Nevertheless, this failure in problem solving is productive. It allows students to develop and try out their own solution and this initial problem-solving increases students’ appreciation of the input of a teacher.


PsychED: However, your findings indicate that exploratory discovery can come with a heavy cognitive load. Could you remind us the signification of this important concept?

Lennart Schalk: Cognitive load is a rather complex concept. Cognitive psychologists assume that humans are equipped with a specific memory system referred to as working memory. An important process of the working memory is the elaboration of new information with information stored in long-term memory. Importantly, the working memory is limited in its capacity; it is the bottle-neck of human information processing. In the cognitive load theory (developed by John Sweller and colleagues in the 1980s and 1990s), there is a distinction between three types of load for the working memory: intrinsic, extrinsic, and germane load. In a nutshell, intrinsic load refers to the difficulty of tasks. Some tasks are intrinsically more difficult than others (e.g., solving a basic multiplication problem like 4 x 3 vs. solving a more complex multiplication problem like 43 x 34). More difficult tasks result in a higher intrinsic load. But obviously, the intrinsic difficulty depends on the prior knowledge of the learner. Extrinsic load originates from the presentation of a task. For example, a mathematics word problem can contain irrelevant details or educators include decorative pictures which look nice but are irrelevant for the task. This irrelevant information increases the extrinsic load. Finally, germane load describes the load of the cognitive system that is devoted to processing information and to construct knowledge representations capturing this information. A possible explanation for why exploratory discovery can be beneficial is that this activity increases the germane load. The experienced load when trying to solve a task might help learners to appreciate a solution that is provided after their own solution attempts. Thus, some amount of cognitive load is beneficial. In the words of Robert A. Bjork this is referred to as desirable difficulties. The task for teachers is to pose tasks that provide the right amount of challenge, not to overload the cognitive systems, but also not to under challenge it.


PsychED: Your experiment tested a new approach to the teaching of mathematics. How would it apply to natural science or humanities?

Lennart Schalk: The problem-solving followed by instruction sequence has mainly been used in mathematics. But, its principles are adaptable to any subject. It is however not easy to develop tasks for this sequence. The problem-solving tasks have to be constructed so that they activate learners knowledge base and to allow for various kinds of solutions attempts. If the problem is too complicated or students do not have relevant prior knowledge that allows them to try out solutions, then the problem-solving followed by instruction approach won’t work. Often the problems actually comprise several problems or examples of a principle. This invites students to compare and contrast across the problems. This comparison process can help to identify the important aspects of a principle on their own. One could for example imagine the following tasks for the humanities. Students should learn about different rhyme schemes. To this aim, the teacher might present students with several poems, some of which have the same rhyme scheme. They could prompt students to try to come up with descriptions of the rhyme scheme. After this exploratory problem solving phase, the teacher would collect students’ solutions and take them up in her/his explanations about rhyme schemes. For overviews of how to design problem-solving followed by instruction sequences and productive failure tasks see Kapur and Bielaczyc (2012) and Loibl, Roll and Rummel (2014). Importantly, the problem-solving followed by instruction sequence is no pure discovery learning; it is strongly structured to the design of the problem-solving tasks.


PsychED: What other areas of pedagogy are you currently interested in?

Lennart Schalk: Most of the pedagogical and educational research is investigating group differences. That is, one class or group is taught following a specific approach, another class or groups is taught following another approach, and then differences between these groups are analyzed. However, learning and development are individual processes. It is hardly possible to generalize from the group to the individual level. I am currently starting research projects in which I will gather intensive longitudinal data. For example, students learn with a software that allows tracking their individual learning progression. This information can then be used to implement individualized support. This approach on the individual level is promising, but still in its infancy. I want to contribute to its maturation because I think that tracking individual students over time provides the information that many researchers and practitioners are actually looking for.
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PsychED: Thank you so much for your time!