Title: Comparing Explicit and Implicit Teaching of Multiple Representation Use in Physics Problem Solving
1Comparing Explicit and Implicit Teaching of
Multiple Representation Use in Physics Problem
Solving
- David Rosengrant, Rutgers, The State University
of New Jersey - Patrick Kohl and N. Finkelstein, University of
Colorado at Boulder
2Talk Outline
- Introduction Solving problems with multiple
representations - Methods Course descriptions
- Data Student use of and success with multiple
representations - Data Student reflection on multiple
representation use - Conclusions
3Introduction
- What do we mean by multiple representations?
- How can we help students to learn to use multiple
representations? - Explicitly
- Implicitly
4The Experiment
- Two large enrollment first-year algebra-based
physics courses. - Rutgers Explicit use and instruction of
multiple representations during concept
construction and problem solving - CU Implicit approach Professor uses a variety
of representations when solving problems in
lecture exams require multiple representation
use little explicit instruction - BOTH courses are PER based
- Questions
- Will the students use multiple representations
differently? - Will they differ in problem solving performance?
5Sources of Data
- 4 electrostatics problems in recitation, plus one
exam/quiz problem - 4 problems are different layout
- Students received credit for attempting
recitation problems
6Course description Rutgers
- Substantial PER-based reforms (ISLE curriculum,
clickers, revised labs and recitations,
ActivPhysics computer simulations) - Heavy and systematic use of multiple
representations in lectures and in recitations - Specialized course packet emphasizing multiple
representations - Explicit instruction on multiple representation
techniques
7Steps in Problem Solving Process
- Picture and Translate
- Sketch the situation described in the problem
include all known information. - Choose a system object and make a list of objects
that interact with the system. - Simplify
- Consider the system as a particle.
- Decide if you can ignore any interactions of the
environment with the system object. - Represent Physically
- Draw a free-body diagram for the system. Label
the forces with two subscripts. Make sure the
diagram is consistent with the acceleration of
the system object (if known). Include
perpendicular x and y coordinate axes. - Represent Mathematically
- Apply Newtons second law in component form to
the situation you represented in the free-body
diagram. - Add kinematics equations if necessary.
- Solve and Evaluate
- Solve the equations for an unknown quantity and
evaluate the results to see if they are
reasonable (the magnitude of the answer, its
units, how the solution changes in limiting
cases, and so forth).
8Free body diagrams (FBD) You are riding to the
top floor of your residence hall. As the
elevator approaches your floor, it slows to a
stop. Construct an FBD for the cable car with
you inside as the object of interest as the car
slows down to a stop.
Cable
Earth
9Course description CU
- Substantial PER-based reforms (clickers, revised
labs and recitations, PhET computer simulations) - Heavy use of multiple representations in lecture
and on exams - Little explicit instruction on multiple
representation techniques
10Data Performance, 4 questions
Prob. 1 Prob. 2 Prob. 3 Prob. 4
Rutgers 0.38 (235) 0.56 0.32 0.38 (155)
CU 0.38 (314) 0.56 0.43 0.40 (269)
- Problem 3 performance difference is significant
at p 0.008 level average difference is not
significant
11Data Representation use, 4 problems
Pictures Prob. 1 Prob. 2 Prob. 3 Prob. 4
Rutgers 0.89 0.89 0.03 0.73
CU 0.92 0.91 0.13 0.90
P-value X X 0.0001 0.0001
Forces per problem Forces per problem
Rutgers 0.59 0.52 0.03 1.71
CU 0.80 0.71 0.11 1.69
P-value 0.05 0.008 0.0002 X
12Data Representation use, exam/quiz problem
Exam Correct 1 Force 2 Forces 3 Forces
Rutgers 0.56 (283) 0.09 0.22 0.51
CU 0.29 (280) 0.23 0.31 0.32
- More than 95 drew a picture at both
universities. - Fraction answering problem correct, and
identifying 1, 2, or 3 forces correctly in
solution. Note Rutgers exam is multiple choice
and CU quiz is free response. - Rutgers students construct complete FBD
significantly (p 0.0001) more often.
13Data Success vs. representation use, exam/quiz
problem
- Note Rutgers test was multiple choice CU quiz
was free-response
14Limitations of Study
- Language favors CU in some cases, Rutgers in
others - Problem 2 asked for Force Diagram, Rutgers
students are familiar with FBD not Force Diagram - Exam problem versus quiz problem
- Graded problem is in different format multiple
choice vs. free response
15Conclusions
- Students in both courses used multiple
representations in their solutions much more
often than in previously studied traditional
courses - Construction of complete FBD is associated with
success, consistent with previous research.1 - Neither approach studied is clearly better
both explicit and implicit instruction approaches
were successful - 1 D. Rosengrant, E. Etkina, and A. Van Heuvelen,
National Association for Research in Science
Teaching 2006 Proceedings, San Francisco, CA
(2006)
16Further Studies
- More trials
- How does the format of the problem influence the
construction of multiple representations? - Preliminary study PERC poster Wed. night
- Future joint studies
17Acknowledgements
- Thanks to Alan van Heuvelen, Mike Dubson, and
Eugenia Etkina. - Special thanks to the Physics Education Research
groups at Rutgers and CU-Boulder - This work was supported in part by an NSF
graduate fellowship.