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Monday afternoon
Dehui Hu, Rochester Institute of Technology
Noah Finkelstein, H. J. Lewandowski. University of Colorado Boulder
Assumptions and idealizations play a significant role in developing and
applying models to real-world situations. Assumptions make models more
tractable, but also impact the design of experiments (through the introduc-
tion of possible sources of systematic error) and limit the range of validity
of predictions. In this investigation, students conducted a think-aloud
laboratory activity using LEDs. Videos were coded and analyzed using
a framework developed for model-based reasoning designed for upper-
division physics laboratory classes. The analysis focuses on multiple roles
of assumptions within the activity: making, recognizing, and justifying as-
sumptions; linking assumptions to limitations of the validity of theoretical
predictions and measured results; and using knowledge of assumptions to
iteratively improve experimental results.
PST1C22: 9:15-10 p.m. Spanning Student Reasoning about P-V
Diagrams in Physics and Engineering*
Poster – Jessica W. Clark, University of Maine, Orono, ME 04468;
John R. Thompson, Donald B. Mountcastle
As part of a new effort to investigate the learning and teaching of concepts
in thermodynamics and electronics in both physics and engineering, we
have been examining student learning of thermodynamics in mechani-
cal and chemical engineering and physics courses. In thermodynamics,
students must grapple with multivariable dependence between state
properties. They are also taught to use simplified models of real substances
(e.g., ideal gas). By varying a task we have previously studied which probes
students’ understanding of the First Law, its constituent elements, and
graphical representations, we access additional specific knowledge of the
univariant temperature dependence of the internal energy of an ideal gas.
Our results show that use of this concept varies across disciplines despite
being covered in all. Additionally, the task alteration suppresses the most
common previously identified difficulty and elicits others to give a more
complete understanding of student reasoning.
*The work described has been supported in part by the National Science Foundation
under Grant Nos. DUE-0817282 and DUE-1323426.
PST1C23: 8:30-9:15 p.m. Exploring a Logical Approach to
Promoting Conceptual Understanding
Poster – David Maloney, Indiana University Purdue University, Fort Wayne,
IN 46805;
An important aspect of scientific understanding is the use of sequential,
inferential reasoning. One school of psychology argues that humans reason
through models. This project is exploring the presentation and use of ex-
plicit models of conditional and bi-conditional statements as a mechanism
for promoting conceptual understanding. Students in a calculus-based
introductory physics course were given a conditional and a bi-conditional
statement involving everyday content. The truth status of each of the seven
possible rearrangements of the original statements was identified for each
case. Students then had a weekly homework assignment that required
explicit use of these models. In addition, there was a test item of the same
format on each of the four tests during the semester. This presentation
will present the struggles the students had with using the logic involved,
with the physics concepts and with connecting the physics with the logical
reasoning.
PST1C24: 9:15-10 p.m. Causal Effects of Reasoning Skills and
Epistemologies on Content Learning
Poster – Lin Ding, The Ohio State University, Department of Teaching and
Learning, Columbus, OH 43210;
Multiple factors can affect content learning. Research in physics education
has tapped into some key factors that are postulated to be causal agents of
learning gains. These include student pre-instructional levels of scientific
reasoning and epistemological sophistication. Previous work in this mat-
ter has largely relied on qualitative case studies or correlation analysis to
demonstrate, separately, the positive relation of reasoning and epistemol-
ogy with content learning. However, the postulated causality has not been
than males when the test was given both as a pre-test and post-test in tradi-
tionally taught calculus-based introductory physics courses. In the algebra-
based courses, the performance of females was significantly worse in the
post-test but there was no statistical difference in the pre-test performance
of males and females. These trends persisted regardsless of the instructors.
We discuss possible reasons for these differences. We thank the National
Science Foundation for support.
PST1C18: 9:15-10 p.m. Investigating Student Difficulties with
Dirac Notation
Poster – Emily M. Marshman, University of Pittsburgh, Pittsburgh, PA 15260;
Chandralekha Singh, University of Pittsburgh
Quantum mechanics is challenging even for advanced undergraduate and
graduate students. Dirac notation is a convenient notation used extensively
in quantum mechanics. We have been investigating the difficulties that the
advanced undergraduate and graduate students have with Dirac notation.
We administered written free response and multiple-choice questions to
students and also conducted semi-structured individual interviews with 23
students using a think-aloud protocol to obtain a better understanding of
the rationale behind their responses. We find that many students struggle
with Dirac notation and they are not consistent in using this notation
across various questions in a given test. In particular, whether they answer
questions involving Dirac notation correctly or not is context dependent.
PST1C19: 8:30-9:15 p.m. Investigating Student Difficulties with
Time Dependence of Expectation Values in Quantum
Mechanics
Poster – Emily M. Marshman, University of Pittsburgh, Pittsburgh, PA 15260;
Chandralekha Singh, University of Pittsburgh
Quantum mechanics is challenging even for advanced undergraduate and
graduate students. In the Schrödinger representation, the wave function
evolves in time according to the time dependent Schrödinger equation. The
time dependence of the wave function gives rise to time dependence of the
expectation value of observables. We have been exploring the difficulties
that advanced undergraduate and graduate students have with time depen-
dence of expectation values in quantum mechanics. We have developed
and administered conceptual free response and multiple-choice questions
to students to investigate these difficulties. We also interviewed 23 students
individually using a think-aloud protocol to obtain a better understanding
of the rationale behind students’ written responses. We find that many stu-
dents struggle with time dependence of expectation values of observables.
We discuss some findings.
PST1C20: 9:15-10 p.m. Analogous Patterns of Student Reason-
ing Difficulties in Introductory Physics and Upper-Level
Quantum Mechanics
Poster – Emily M. Marshman, University of Pittsburgh, Pittsburgh, PA 15260;
Chandralekha Singh, University of Pittsburgh
Very little is known about how the nature of expertise in introductory and
advanced courses compares in knowledge-rich domains such as physics.
We develop a framework to compare the similarities and differences be-
tween learning and patterns of student difficulties in introductory physics
and quantum mechanics. Based upon our framework, we argue that the
qualitative patterns of student reasoning difficulties in introductory phys-
ics bear a striking resemblance to those found for upper-level quantum
mechanics. The framework can guide the design of teaching and learning
tools.
PST1C21: 8:30-9:15 p.m. Assumptions and Idealizations in
Students’ Reasoning During Laboratory Activities
Poster – Benjamin M. Zwickl, Rochester Institute of Technology, Rochester,
NY 14623-5603;
