Katherine K. Perkins

Transforming Physics Education

By using the tools of physics in their teaching, instructors can move students from mindless memorization to understanding and appreciation.

PhET: Interactive Simulations for Teaching and Learning Physics

The Physics Education Technology (PhET) project creates useful simulations for teaching and learning physics and makes them freely available from the PhET website (http://phet.colorado.edu). The simulations (sims) are animated, interactive, and game-like environments in which students learn through exploration. In these sims, we emphasize the connections between real-life phenomena and the underlying science, and seek to make the visual and conceptual models of expert physicists accessible to students. We use a research-based approach in our design—incorporating findings from prior research and our own testing to create sims that support student engagement with and understanding of physics concepts.The Physics Education Technology (PhET) project creates useful simulations for teaching and learning physics and makes them freely available from the PhET website (http://phet.colorado.edu). The simulations (sims) are animated, interactive, and game-like environments in which students learn through exploration. In these sims, we emphasize the connections between real-life phenomena and the underlying science, and seek to make the visual and conceptual models of expert physicists accessible to students. We use a research-based approach in our design—incorporating findings from prior research and our own testing to create sims that support student engagement with and understanding of physics concepts.

Correlating Student Beliefs With Student Learning Using The Colorado Learning Attitudes about Science Survey

A number of instruments have been designed to probe the variety of attitudes, beliefs, expectations, and epistemological frames taught in our introductory physics courses. Using a newly developed instrument — the Colorado Learning Attitudes about Science Survey (CLASS) — we examine the relationship between students’ beliefs about physics and other educational outcomes, such as conceptual learning and student retention. We report results from surveys of over 750 students in a variety of courses, including several courses modified to promote favorable beliefs about physics. We find positive correlations between particular student beliefs and conceptual learning gains, and between student retention and favorable beliefs in select categories. We also note the influence of teaching practices on student beliefs.

Transforming Science Education at Large Research Universities: A Case Study in Progressxs

There are countless reports stressing the economic and societal benefits to be gained from improved science, technology, engineering, and math (STEM) education for all students. But although there ...

Twilight observations suggest unknown sources of HOx

Measurements of the concentrations of OH and HO_(2) (HO_(x)) in the high-latitude lower stratosphere imply the existence of unknown photolytic sources of HO_(x). The strength of the additional HO_(x) source required to match the observations depends only weakly on solar zenith angle (SZA) for 80° < SZA < 93°. The wavelengths responsible for producing this HO_(x) must be longer than 650 nm because the flux at shorter wavelengths is significantly attenuated at high SZA by scattering and absorption. Provided that the sources involve only a single photon, the strength of the bonds being broken must be < 45 kcal mole^(−1). We speculate that peroxynitric acid (HNO_4) dissociates after excitation to an unknown excited state with an integrated band cross section of 2-3 × 10^(−20) cm^(2) molecule^(−1) nm (650 < λ < 1250 nm).

Developing and researching PhET simulations for teaching quantum mechanics

Quantum mechanics is counterintuitive, difficult to visualize, mathematically challenging, and abstract. The Physics Education Technology (PhET) Project now includes 18 simulations on quantum mechanics designed to improve the learning of this subject. These simulations include several key features to help students build mental models and intuition about quantum mechanics: visual representations of abstract concepts and microscopic processes that cannot be directly observed, interactive environments that directly couple students’ actions to animations, connections to everyday life, and efficient calculations so that students can focus on the concepts rather than the mathematics. Like all PhET simulations, these are developed using the results of research and feedback from educators, and are tested in student interviews and classroom studies. This article provides an overview of the PhET quantum simulations and their development. We also describe research demonstrating their effectiveness and discuss some i...

Temperature and pressure dependent kinetics of the gas-phase reaction of the hydroxyl radical with nitrogen dioxide

The reaction of OH with NO2 is pivotal in both stratospheric and tropospheric chemistry; in each case it is the dominant homogeneous mechanism for conversion of NOx to NOy. The rate constant is a strong function of pressure and temperature, and key portions of the pressure-temperature domain are poorly or ambiguously covered by the available data. These include conditions typical of the tropospheric boundary layer and of the lower stratosphere. At surface conditions differences of 60% exist both in the literature data and between the major recommendations, while at lower stratospheric conditions there are few available data. Our High Pressure Flow kinetics system is ideally suited to studying this reaction, as we are able to scan both temperature and pressure while maintaining wall-less conditions, eliminating the possible complications of heterogeneous chemistry. Here we report a temperature- and pressure-dependent study (220–300 K, 50–150 torr) of this reaction; the measured rate constants are in excellent agreement with previously published values down to 240 K, but lie 10–20% lower than the historical data available below that temperature. An analysis of all available data motivates a large (∼ 20%) downward revision in the recommended rate constant below room temperature.

Oersted Medal Lecture 2007: Interactive simulations for teaching physics: What works, what doesn’t, and why

We give an overview of the Physics Educational Technology (PhET) project to research and develop web-based interactive simulations for teaching and learning physics. The design philosophy, simulation development and testing process, and range of available simulations are described. The highlights of PhET research on simulation design and effectiveness in a variety of educational settings are provided. This work has shown that a well-designed interactive simulation can be an engaging and effective tool for learning physics.

The Surprising Impact of Seat Location on Student Performance

Every physics instructor knows that the most engaged and successful students tend to sit at the front of the class and the weakest students tend to sit at the back. However, it is normally assumed that this is merely an indication of the respective seat location preferences of weaker and stronger students. Here we present evidence suggesting that in fact this may be mixing up the cause and effect. It may be that the seat selection itself contributes to whether the student does well or poorly, rather than the other way around. While a number of studies have looked at the effect of seat location on students, the results are often inconclusive, and few, if any, have studied the effects in college classrooms with randomly assigned seats.1 In this paper, we report on our observations of a large introductory physics course in which we randomly assigned students to particular seat locations at the beginning of the semester. Seat location during the first half of the semester had a noticeable impact on student su...

Research‐based Practices For Effective Clicker Use

Adoption of clickers by faculty has spread campus‐wide at the University of Colorado at Boulder from one introductory physics course in 2001 to 19 departments, 80 courses, and over 10,000 students. We study common pedagogical practices among faculty and attitudes and beliefs among student clicker‐users across campus. We report data from online surveys given to both faculty and students in the Spring 2007 semester. Additionally, we report on correlations between student perceptions of clicker use and the ways in which this educational tool is used by faculty. These data suggest practices for effective clicker use that can serve as a guide for faculty who integrate this educational tool into their courses.