New PSRC collection resources

Multiple Modes of Reasoning in Physics Problem Solving, with Implications for Instruction

Tue, 17 Nov 2009 15:31:22 EST

Problem-solving is an important part of physics teaching, learning and assessment. It is widely assumed that the way that experts solve problems, and students should, is by systematic application of basic physics principles. Model solutions are laid out this way, and teaching of problem-solving usually consists of `going over' such solutions step by step. However, while this does represent the physics structure of the final solution, it does not adequately reflect how people actually think when tackling problems. Real cognition is complex. This study was prompted by students trying to `map across' result features recalled from previous cases instead of working from basics. Since our instruction emphasizes the power and generality of basic principles, our first response was to re-emphasize principles, but we found that experts in fact draw extensively and effectively on rich compiled case knowledge. We investigated cognition in detail for geometrical optics. Research methods included analysis of written solutions, reflections on thinking, and interviews. Cognitive modes emerged from the initial research stages, and were then used to code individuals' problem-solving pathways. Learners and experts alike used multiple modes of cognition, significantly principle-based reasoning, case-based reasoning and experiential-intuitive reasoning. Case-based reasoning using pre-compiled knowledge played a pervasive role in conjunction with, and sometimes in conflict with, principle-based reasoning. The implications for instruction are that it should reflect what we know about cognition and expertise, and hence include teaching case-based as well as principle-based reasoning. We are doing this in optics, by using cases and variations, identifying topic knowledge schema `sub-assemblies', and modeling their use in problems.

Teaching Physics Using Virtual Reality

Tue, 17 Nov 2009 13:57:16 EST

This web site provides pedagogical material to use with Real Time Relativity, a virtual relativistic world simulator. Included are a lab using the software, student evaluations, and web resources for teaching relativity.

Science Fiction Stories with Good Astronomy and Physics: A Topical Index

Sun, 15 Nov 2009 10:23:24 EST

This is a selective list of some short stories and novels that use more or less accurate science. They can be used for teaching or reinforcing astronomy or physics concepts. Both traditional "science-fiction" and (occasionally) more serious fiction that derives meaning or plot from astronomy or physics ideas are included. Almost 200 stories in 40 subject categories are listed.

New Faculty Workshop, Fall 2009

Sat, 14 Nov 2009 12:06:49 EST

The Fall 2009 New Faculty Workshop schedule and presentations are available.

Real Time Relativity

Tue, 10 Nov 2009 21:35:00 EST

This web site hosts a computer program that allows the user to interactively experience a virtual relativistic world. It is available for both Windows and Mac computers. This software is a central element of the project Teaching Physics Using Virtual Reality. It provides a conceptual introduction to special relativity by experiencing it in a virtual world.

Web-based Quantum Mechanics I Course

Fri, 06 Nov 2009 21:45:10 EST

This web site is an entire web-based Quantum Mechanics I Course based at the University of Tennessee. It includes instructional materials, in-class tutorials, simulations, links to other quantum resources, homework assignments, and solutions.

Introduction to Physics in Modern Medicine: Resource Website

Mon, 26 Oct 2009 10:06:34 EST

This web page provides resources to support a textbook on physics in modern medicine. Included in these resources are lists of articles, reference books, and videos. There is also a list of Errata for the first edition of the the textbook. Also included on this resource page are manuals and instructions for three medical-physics related laboratories on optics, ultrasound, and radiography. The author also provides links to vendors and other resources for experiments suitable for this course.

Physics in Modern Medicine: Applications in Imaging, Surgery, and Therapy

Mon, 26 Oct 2009 09:49:44 EST

This is the website for a course on medical technologies and the physical principles behind them for non-scientists. Topics covered include laparoscopic and laser surgery, photodynamic therapy, and a range of imaging techniques. Included on this page is the course syllabus and a list of internet resources that will be useful to help students research projects.

Newton's Laws in Action

Fri, 23 Oct 2009 22:10:47 EST

This page describes Newton's Laws and their relation to conservation of energy and momentum and provides examples.

The Moon: A Resource Guide

Sun, 18 Oct 2009 10:37:05 EST

The guide covers the scientific understanding of the Moon as a world, the appearance of the Moon, and tips for observing the Moon. It is written for educators, amateur astronomers, and anyone with an interest in the Earth's natural satellite. It also suggests a few ways to learn more about the Moon in popular culture and historical events. This resource list is part of a series of guides for educators from the Astronomical Society of the Pacific, which is dedicated to improving the public understanding of astronomy and advancing science literacy. These materials are available online at http://www.astrosociety.org/education.html

Falling Slinky Model

Thu, 08 Oct 2009 22:43:21 EST

The Falling Slinky model approximates a slinky using twenty masses connected with light springs. The slinky is suspended from one end and released. Two actions will occur simultaneously when it is released hanging at rest from its equilibrium position - it will fall and it will collapse. What happens to the bottom when it begins its fall?

The bottom end will move up initially.
The bottom end will move down initially.
The bottom end will remain at the same point for a short time before it begins to move.

The Falling Slinky model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double click the ejs_mech_newton_FallingSlinky.jar file to run the program if Java is installed.

First Explanations, Early Greek Astronomy

Wed, 09 Sep 2009 10:56:58 EST

This web page outlines some of the ideas and concepts used by early scientists and philosophers to explain observations of celestial objects. The author provides some history and background of the beliefs of the ancient Greeks, Egyptians and Persians. An example of how geometry was used in early astronomy along with a similar exercise using more accurate and modern data are given. Also a link is provided for constructing a formal scientific report.

Earth Orbit Model

Wed, 02 Sep 2009 14:48:53 EST

The EJS Earth Orbit model illustrates the Copernican theory of Earth's orbit around the sun. The top window shows a view from outside the celestial sphere. The simulation shows the moving Earth along with its axis or rotation and the line of sight from Earth, through Sun, to the Celestial Sphere. The end of the arrow indicates where, on the Celestial Sphere, Sun appears to be located as seen from Earth. The tilt of Earth's rotational axis (relative to the ecliptic plane) is adjustable. The bottom window shows the view of a portion of the sky (near the ecliptic) as seen by an observer on Earth. You can modify this simulation if you have EJS installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu item. EJS Earth Orbit model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_astronomy_EarthOrbit.jar file will run the program if Java is installed. EJS is a part of the Open Source Physics Project and is designed to make it easier to access, modify, and generate computer models. Additional EJS models for astronomy are available. They can be found by searching ComPADRE for Open Source Physics, OSP, or EJS.

RELATE real-world problem index

Wed, 02 Sep 2009 14:42:57 EST

This collection of mechanics problems provide real-world examples of applications of physics. Each problem contains a description of an event or experiment with data. Students are asked questions to explore and explain the situation. Each of the problems in the collection are described by their topic, concept, and difficulty.

Falling Cup with Ball Model

Wed, 02 Sep 2009 14:34:57 EST

The Falling Cup with Ball model shows a mass attached to the inside of a cup with a light spring. The cup is held upside down, with the mass hanging out of the cup, then released from rest. What happens when the cup is released?

The mass will extend the spring, like a parachute, due to air pressure pulling on the cup.
The mass will be pulled up into the cup by the spring?
The cup will fall with the mass in its original position?

The Falling Cup with Ball model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double click the ejs_mech_newton_FallingCupWithBall.jar file to run the program if Java is installed.

OU Engineering Media Lab: Significant Digits

Wed, 19 Aug 2009 17:38:49 EST

This item is an interactive demonstration of the topic of significant digits. It computes the error that can be introduced by rounding during a calculation. Users input numbers and operations and select the number of significant digits for rounding the inputs. The result of the calculation is computed using the actual and rounded inputs, along with the percent difference between two. Users may select from addition, subtraction, multiplication, and division for the operations. This item is part of a collection of instructional materials for introductory engineering courses on six topics: Statics, Dynamics, Fluids, Thermodynamics, Calculus, and Multimedia. See related items on this page for a link to the complete collection.

The Applet Collection: Significant Figures

Wed, 19 Aug 2009 13:48:54 EST

This Java applet is a game designed to provide practice in significant figures for beginners. Users view a number and must determine the number of significant figures. Scores are automatically tallied, with short explanations given for incorrect responses. This item is part of a larger collection of physics applets.

Introducing Ill-Structured Problems in Introductory Physics Recitations

Sat, 15 Aug 2009 22:47:30 EST

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 paper focuses on ill-structured problems. These problems are different from traditional “end of chapter” well-structured 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. We present a scaffolding technique for introducing ill-structured problems in introductory physics recitations and describe preliminary results of an exploratory study of student problem solving of ill-structured problems.

Effect of Misconception on Transfer in Problem Solving

Sat, 15 Aug 2009 22:46:10 EST

We examine the effect of misconceptions about friction on students' ability to solve problems and transfer from one context to another. We analyze written responses to paired isomorphic problems given to introductory physics students and discussions with a subset of students. Misconceptions associated with friction in problems were sometimes so robust that pairing them with isomorphic problems not involving friction did not help students fully discern their underlying similarities.

Symbols: Weapons of Math Destruction

Sat, 15 Aug 2009 22:44:28 EST

This paper is part of an ongoing investigation of how students use and understand mathematics in introductory physics. Our previous research [1] revealed that differences in score as large as 50% can be observed between numeric and symbolic versions of the same question. We have expanded our study of numeric and symbolic differences to include 10 pairs of questions on a calculus based introductory physics final exam. We find that not all physics problems exhibit such large differences and that in the cases where a large difference is observed that the largest difference occurs for the poorest students. With these 10 questions we have been able to develop phenomenological categories to characterize the properties of each of the questions. We will discuss what question properties are necessary to observe differences in score on the numeric and symbolic versions. We will also discuss what insights these categories give us about how students think about and use symbols in physics.