PER-based Techniques in a Large Lecture Modern Physics Course for Engineers

Sam McKagan, Katherine Perkins, and Carl WiemanUniversity of Colorado at Boulder

http://per.colorado.edu

Physics 2130 is a course in modern physics for engineering majors. We taught a reformed version of this course in Fall 2005 and Spring 2006.1 Our reforms were based on the following work done before the course:

• Review existing research on student understanding of QM.• Interview physics professors who have recently taught course: “What

are the most important concepts you want students to learn from this course?”

• Interview engineering professors: “What do your students need to know about modern physics?”

• Set up problem-solving session for students enrolled in traditional course to observe common difficulties.

• Develop a Quantum Mechanics Conceptual Survey to assess student learning in this course (and others).

• Interview students to validate QMCS and further examine student ideas about these topics.

Introduction

End NotesAssessment of Course

Acknowledgements

Research Related to Course

References

Collaborative Homework Sessions Peer InstructionInteractive Simulations

Measuring Effectiveness of Instruction on Photoelectric Effect

• The Physics Education Technology (PhET)5 Project is an on-going effort to create a suite of interactive simulations and related education resources that aid in the teaching and learning of physics.

• We have developed many new QM simulations for use in this course and elsewhere:

CLASS (Colorado Learning and Attitudes about Science Survey)

• 9 hours per week of problem-solving sessions where students could work together on homework

• Staffed by learning team of instructors, TAs, and undergraduate learning assistants (LAs).

• Laptops available for students to use simulations.• Focused on getting students to work together to figure out the homework, not answering questions.

• Goal: make homework so hard that students have to work together.• Learning team observed that the level of sophistication of students’ questions increased over course of semester.

Our instruction on the Photoelectric Effect included:• Three 50 minute lectures with many concept tests and interactive lecture

demos with Photoelectric Effect simulation.• Several homework questions involving Photoelectric Effect simulation.Previous Research:• Steinberg, Oberem, and McDermott6 tested the effectiveness of Photoelectric

Tutor (PT), a computer program to aid in teaching the photoelectric effect, by asking the following exam question in a modern physics class at the University of Washington (UW), with students who did and did not use PT.

Our Study:• We asked the same exam question, with the order changed and the wording

modified to be consistent with the vocabulary used in our course.• Twice as many of our students answered Q3 correctly as those using PT.

Student Responses:

1. For course materials, contact the authors or go to: http://jilawww.colorado.edu/~mckagan/2130archive/

2. Quantum Mechanics Conceptual Survey: http://cosmos.colorado.edu/phet/survey/QMCS/

3. Sam McKagan, Katherine Perkins, Wendy Adams, Danielle Harlow, Michael Dubson, Chris Malley, Sam Reid, Ron LeMaster, Carl Wieman, “Teaching Quantum Mechanics with PhET Simulations, Poster DB06-10 AAPT 2006.

4. Sam McKagan, Katherine Perkins, and Carl Wieman, “Case Studies of Student Understanding and Beliefs in Modern Physics,” Talk DF05 and Poster EJ02-05 AAPT 2006.

5. Physics Education Technology Project, http://phet.colorado.edu.

6. Richard N. Steinberg, Graham E. Oberem, and Lillian C. McDermott, “Development of a computer-based tutorial on the photoelectric effect,” American Journal of Physics 64, 1370 (1996).

•Development and testing of Quantum Mechanics Conceptual Survey.2

•Case studies of six students – tracking the development of understanding and attitudes through regular interviews throughout course.3

•Development and testing of PhET simulations in QM.4

•Study of how simulations contribute to student understanding and ability to visualize and recall complex phenomena.

•Tracking how studying QM affects students’ attitudes about science.

•Study of techniques for teaching models of the atom, and how this affects students’ overall understanding of atoms.

•Study of student understanding of quantum tunneling.

Course Pre Post Shift N

Ref. Eng. Sp06 66.1 67.1 1.0* 135

Ref. Eng. Fa05 70.2 68.0 -2.1* 150

Trad. Eng. Sp05 68.5 60.5 -8.0* 55

Trad. Phys. Sp06 72.1 67.2 -4.9* 25

Trad. Phys. Fa05 78.6 72.9 -5.7* 47

Trad. Phys. Sp05 78.5 74.8 -3.7* 61

In a typical physics course, students’ favorable (expert-like) responses to CLASS questions decrease significantly from pre to post. The shifts for our reformed classes are not statistically significant.

QMCS (Quantum Mechanics Conceptual Survey)

% FavorableCourse Pre Post

normalized gain N

Ref. Eng. Sp06 30 65 0.50 156

Ref. Eng. Fa05 32 69 0.55 162

Trad. Eng. Sp05 (30) 51 0.30 68

Trad. Phys. Sp06 44 64 0.36 23

Trad. Phys. Fa05 40 53 0.21 54

Trad. Phys. Sp05 (44) 63 0.33 64

% Correct

The QMCS is still in development and has gone through several versions. The analysis here includes only the 12 questions that were asked all three semesters. Because no pretest was given in Spring 2005, we assumed the incoming population was similar to the following spring. The normalized gains for reformed (traditional) classes are similar to normalized gains on the FCI for reformed (traditional) classes.

Course Q1 (c) Q2 (a) Q3 (b) N

UW w/o PT 65 40 20 26

UW w/ PT 75 85 40 36

CU Fa05 88 85 84 189

CU Sp06 78 84 79 182

Percentage of students who correctly answered exam questions

Common exam questions

Instructors observed that most students did not know the correct answer initially, but many were able to figure it out through discussion. Graphs that students drew, before seeing multiple choice options, closely matched given options.

• Used H-ITT infrared “clickers” to ask concept tests in class.• Questions designed to stimulate discussion, elicit misconceptions, or ask students to predict as in interactive lecture demo.

• Three instructors and three LAs circulated through the class to stimulate student discussion and make observations.•Quantum Tunneling

•Quantum Wave Interference•Quantum Bound States•Nuclear Physics•Davisson Germer: Electron Diffraction•Photoelectric Effect•Lasers•Discharge Lamps•Simplified MRI•Conductivity•Semiconductors

• We used these simulations extensively in lecture to illustrate key ideas and as part of interactive lecture demos, and as part of homework problems.

• The simulations helped students build mental models of abstract and unobservable phenomena.

• On final exam, we found that students could give very detailed explanations about topics where we used simulations, but not about other topics.

The authors thank the NSF for providing the support for this project. We also thank all the members of the PhET Team and the Physics Education Research at Colorado group (PER@C).

Many students are confused about the meaning of potential energy. This question effectively addresses this confusion early in the course.

Sample Homework Problem

Student Responses:Sample Concept Tests

Physics 2130

Modern Physics for Engineering

Majors

~200 students

Interactive simulation

s

Collaborative

Homework sessions

Peer Instruction

Solving complex 3D

Schrodinger problems

Memorization

Reasoning Development: How do we make

inferences from observations?

Real World Examples: PMTs, discharge

lamps, fluorescent lights, lasers, alpha decay, STMs, LEDs, CCDs,

MRIs, BEC

Special R

elativity

Model Building:

Why do we believe this

stuff?