Session P20: Invited Session: Scientific Reasoning in a Physics Course

Empowering the crowd: faculty discourse strategies for facilitating student reasoning in large lecture

Oregon State University (OSU) has restructured its introductory calculus-based sequence including reformed curriculum modeled after the Interactive Science Learning Environment (ISLE). ISLE is driven by an experimental cycle roughly summarized as: observe phenomena, find patterns and devise explanations, test explanations, develop a model, apply the model to new observations. In implementing ISLE at OSU we have chosen to focus on student scientific reasoning, specifically student ability to develop and test models, make explicit judgments on how to approach open-ended tasks, and take an authoritative role in knowledge development. In order to achieve these goals, the lecture course heavily utilizes social engagement. During large-lecture group work, emphasis is placed on facilitating student discourse about issues such as what systems to choose or how to define an open-ended problem. Instructional strategies are aimed at building off the group discourse to create a full-class community where knowledge is developed through collaboration with peers. We are achieving these goals along with an increase in measured student conceptual knowledge and traditional problem solving abilities, and no loss of content coverage. It is an ongoing effort to understand ``best'' instructional strategies and to facilitate new faculty when they teach the curriculum. Our research has focused on understanding how to facilitate activities that promote this form of discourse. We have quantitative analysis of engagement based on video data, qualitative analysis of dialogue from audio data, classroom observations by an external researcher, and survey data. In this session we share a subset of what we have learned about how to engage students in scientific reasoning discourse during large lecture, both at the group-work and full-class level.   

Designing and using multiple-possibility physics problems in physics courses

One important aspect of physics instruction is helping students develop better problem solving expertise. Besides enhancing the content knowledge, problems help students develop different cognitive abilities and skills. This presentation focuses on multiple-possibility problems (alternatively called ill-structured problems). These problems are different from traditional ``end of chapter'' single-possibility problems. They do not have one right answer and thus the student has to examine different possibilities, assumptions and evaluate the outcomes. To solve such problems one has to engage in a cognitive monitoring called epistemic cognition. It is an important part of thinking in real life. Physicists routinely use epistemic cognition when they solve problems. I have explored the instructional value of using such problems in introductory physics courses.   

Assessing high-level scientific reasoning in a physics exam: Pipe-dream or reality?

What do we want students to be able to do when they have finished their introductory physics course? In addition to learning the physics content, we want students to learn to think like physicists. We want students to develop specific scientific reasoning abilities that are the hall-mark of scientific thinking. These include, analyzing and interpreting experimental data, designing an experiment to test different hypotheses, identifying assumptions in a physical model amongst many others. Physics courses such as the Investigative Science Learning Environment (ISLE) have been developed to focus specifically on developing students' scientific reasoning abilities. Research has shown that ISLE is successful in achieving its goal. We would like our assessments to directly reflect our learning goals for our students. In order to measure higher-level scientific reasoning, we can, for example, require students to participate in a laboratory practical exam in which they have to engage in experimental design and analysis. However, this assessment method could become very difficult to administer and grade in a large-enrollment class. Is it possible to assess scientific thinking abilities of students using traditional formats such as paper and pencil exams? In this talk I will present some of our latest ideas about how to re-design traditional exam questions to measure a range of scientific reasoning abilities.   

Using mathematics to make sense in undergraduate physics

Physics courses involve the study of physical quantities constructed to facilitate the characterization of nature, and the study of the connections between these quantities. These connections are often ratios or products of more familiar quantities. Learning to use the predictive power these relationships provide is an important part of learning to make sense of the physical world. Mathematically inspired reasoning is foundational to the way physicists make sense of the natural world and math is often referred to as the language of physics. Students rarely understand the relationships between the physical quantities in the way their instructors hope they will. There is often a disconnect between the specialized way we use mathematics in physics and the broad spectrum of processes that students learn to master as they progress through the pre-college mathematics curriculum. We are often surprised by how little math our students are able to use in physics, despite successful performance in their previous math classes. Much of the reasoning used in introductory physics is borrowed from mathematics that is taught in middle school and early high school (facility and practice with integers, fractions and ratios, multiplication and division using symbolic representations, manipulation of linear equations, analyzing right triangles.) But physics is a very different context, with confounding factors that often render the mathematics opaque to the learner. In this talk, I will discuss the specific ways in which physicists' use of mathematics differs from what many students acquired in their math classes. I will discuss how a weak mastery of conceptualizing fundamental mathematical operations interferes with students' ability to make sense in physics, and can carry over into difficulties with subsequently more abstract reasoning at higher levels. I will also offer suggestions for ways in which instructors can be more cognizant of (and transparent about) their specialized use of mathematics, thereby helping their students to effectively use mathematics for making sense of the physics they are learning.   

Student reasoning about ratio and proportion in introductory physics

To many students, introductory physics must seem a fast-moving parade of abstract and somewhat mysterious quantities. Most such quantities are rooted in proportional reasoning. Using ratio, physicists construct the force experienced by a unit charge, and attach the name electric field, or characterize a motion with the velocity change that occurs in a unit time. While physicists reason about these ratios without conscious effort, students tend to resort to memorized algorithms, and at times struggle to match the appropriate algorithm to the situation encountered. Although the term ``proportional reasoning'' is prevalent, skill in reasoning with these ratio quantities is neither acquired nor applied as a single cognitive entity. Expert ability seems to be characterized by the intentional use of a variety of components, or elements of proportional reasoning, by a fluency in shifting from one component to another, and by a skill in selecting from among these components. Based on this perspective, it is natural to expect students to develop proportional reasoning ability in fits and starts as various facets are acquired and integrated into existing understandings. In an ongoing collaboration between Western Washington University, New Mexico State University, and Rutgers, we are attempting to map the rich cognitive terrain of proportional reasoning, and to use our findings to guide the design of instruction that develops fluency. This talk will present a provisional set of proportional reasoning components, along with research tasks that have been developed to measure student ability along these components. Student responses will be presented as evidence of specific modes of thinking. The talk will conclude with a brief outline of our approach to improving student understanding.