United States

Proficiency in units/dimensional analysis is a useful skill in the sciences and engineering, and STEM instructors often presume competence from their students in this area. However, unit analysis techniques and unit systems are not always formally taught, and even with explicit emphasis during instruction, many students lack the repeated exposure necessary to master them. To assess student understanding of units and unit systems, we administered a brief, itemized survey to N=53 calculus-based introductory university physics students. The survey was intended to uncover possible misconceptions and identify previously unknown obstacles to student success within this topic. Our results suggest that as many as half of surveyed participants may not recognize the adaptability of symbolic physical equations to different unit systems. Furthermore, a similar proportion failed to eliminate non-viable answer choices involving analytic functions with units inside their arguments. Consequently, we believe units/dimensional analysis is a topic ripe for further investigation.

AAPT SM 20

Excerpts from an exploratory survey of units/dimensional analysis in introductory physics

dimensional analysis

units

introductory physics

Join us in exploring emergent themes in PER as a scholarly endeavor and as a research community!  Since its inception, PER has served as a confluence of discipline, theory, research methodology, practice, and application.  How have these facets and the interplays among them been fruitful for physics education globally, regionally, locally, or otherwise?  And, how have our successes and interactions influenced the very nature of PER itself?
Following the lead of AAPT for the summer meeting, PERC 20/20 was virtual. Enjoy browsing the content.

PERC SM 20

Since its inception, PER has served as a confluence of discipline, theory, research methodology, practice, and application.  How have these facets and the interplays among them been fruitful for physics education globally, regionally, locally, or otherwise?  And, how have our successes and interactions influenced the very nature of PER itself?

technical paper

The 2020 AAPT Virtual Summer Meeting brought together physics educators from around the globe to learn about the latest in physics theory, research methodology and education from leaders in their field. The program featured plenary speakers, sessions, workshops and many special activities.

For more information please visit the 2020 AAPT Virtual Summer Meeting page at: https://www.aapt.org/Conferences/SM2020/index.cfm.


The 2020 AAPT Virtual Summer Meeting brought together physics educators from around the globe to learn about the latest in physics theory, research methodology and education from leaders in their field. 

Model Rocket engines have provided students at St. Catherine University the opportunity to review concepts about impulse, energy and kinematics. In what is now fondly called ‘the rocket lab’ students build a rocket at the end of one lab session and then proceed to launch and calculate the altitude the model reaches theoretically using impulse and conservation of energy. Students are then able to experimentally measure the altitude using trigonometry and from an altitude box attached to the nose cone. The lab allows for discussion related to sizing i.e. ½ A vs A in terms of the impulse delivered by the engine. We are also able to talk about how the changing mass generates the thrust needed to propel the rocket skywards. Our students have found this lab to be an effective way to learn these topics in their courses.

Model Rocket Engines

Interpretation of student behavior in online learning platforms based on clickstream data is complicated by not being able to directly observe the learner. This leads to difficulties in understanding inherently unobservable effects on the students’ clickstream data. For example, we try to calculate the amount of time that each student spent studying the instructional material in each module, which requires estimating certain properties of the resulting data. Consequently, the major issue we address in this work is the difficulty of making reasonable cutoffs for abnormally short and abnormally long events. Students enrolled in introductory mechanics courses participated in a study where they completed online homework modules in a controlled, observed environment. In this talk, we will present comparisons between students’ clickstream data for those who were observed and those who were not observed, and for the same student in proctored and non-proctored sessions on different modules.

Direct observation of student behavior in online learning modules

Faculty in the Loyola University Chicago (LUC) Physics Department initiated the “Freshman Project” in 1996. This project has continued each year until today, becoming a separate one-credit course that is a graduation requirement for majors in the department. Students, generally in their first year in the major, work in small groups with a faculty mentor, carrying out a semester-long investigation designed to model many aspects of the research experience. Students propose an investigation, design and carry out an experiment, conduct theoretical analysis, and present their results at a department symposium. I will discuss the important role this program has played in the growth and development of the Physics Department at LUC, as well as the benefits of engaging students in this activity early in their undergraduate careers.

A First-Year Research Experience for Physics Majors

The Next Generation Science Standards (NGSS) define a set of Science and Engineering Practices, which map well to the focus areas of the "AAPT Recommendations on the Undergraduate Laboratory Curriculum." Both of these promote development of skills and competencies critical for the research environment and employment in a range of job sectors, and, together, they provide a way to bridge scientific and engineering practices from K-16. This talk will give an overview of and mapping between the NGSS and AAPT Lab Recommendations and will discuss how skill development can be scaffolded from the NGSS high school curriculum through the undergraduate curriculum.

Bridging Skill Development from NGSS to the AAPT Laboratory Recommendations

It is a given that not everyone who starts their Ph.D. in physics will complete it. That being said, there are people who have the great potential of being competent and able researchers that leave without the Ph.D. Using techniques from the Georgia Tech Center for Deliberate Innovation, based in developmental psychology and behavioral economics, we are working to see more clearly what might be getting in the way of competent, motivated students who fail to complete their Ph.D.

Using Deliberate Innovation Methodologies to Enable Graduate Student Success

Recent science education reform calls for argumentation as one of the central practices in science classrooms. However, evaluating student argumentation proficiency is challenging. Based on an existing learning progression of argumentation and grade-appropriate objectives, we developed a measure for middle-school students in three contexts (e.g. kinetic theory of gases) of 19 constructed response items. Experts coded responses from 932 middle-school students for components of argumentation and used these coded responses to train machine learning algorithms for each item. The algorithms were validated using a cross-validation approach. We found that the machine-human agreements are robust, with a mean Cohen’s kappa=0.75, SD=0.08. We further applied a many-facet Rasch analysis and found the item difficulty in this measure is well aligned with the established learning progression. The algorithms developed in this study can be used in classrooms to automatically evaluate students’ argumentation proficiency.

Applying Machine Learning to Automatically Assess Middle-School Students’ Argumentation

Student issues with both understanding electrical potential and difficulties with interpreting diagrams have been well explored. A major issue in student ranking of electric potentials is identification of the sign of the electric charge. An investigation of modifying traditional equipotential diagrams based on theories of visual affordances to improve students’ recognition of electric change sign when ranking electric potential was undertaken. A prior study showed equipotential diagram modifications significantly increased student gaze times at the diagrams without increasing students’ overall correctness rates. In this study modifications of color and line style were made to equipotential lines to increase visual salience of indicators of change sign. Students were randomly assigned to the traditional or modified diagrams and asked to compare electric potentials for indicated points on given diagrams. Pre- and post-test comparisons and the results of student interviews will be presented to clarify the specific issues students have reading equipotential diagrams.

Changes to equipotential diagrams to improve student ranking of electric potential

Our overall goal is to develop “diagnose-and-practice” resources to help students in our introductory physics courses improve their accuracy and fluency on math skills necessary for success. In this phase of the project we focused on developing and testing online practice exercises. In each of 11 lecture sections, all students were assigned to practice either trigonometry or linear equations using our online platform multiple times throughout the semester. We observed that on average, students in both conditions decreased in pre -to-post time on all items, with the relevant treatment group showing larger decrease for some of the relevant test items. Accuracy scores were high with no differences between conditions. We also tracked student accuracy and time during their practice throughout the semester and found student improvement in accuracy and/or time for some categories, but not for others. A new practice protocol will be implemented in AU2020 based on these results.

Online practice of trigonometry and linear equations skills for physics

We teach Optics by leveraging a coherent series of hands-on laboratory engagements that connect well with classroom discussion of mathematical modeling. These labs directly explore mathematical models contained in Optics texts, commonly utilizing liquid crystal Spatial Light Modulators (SLMs), which allow simple and direct programmatic control of phase, amplitude, or polarization across the field of a beam of light. As added bonus, their use avoids the excessive burdens associated with manual alignment and re-alignment (and re-alignment and...) that would be required for systematic studies based on traditional (fixed) optical components. Again, SLMs allow direct control of amplitude and phase modulation of beams, which is useful for teaching Fresnel Diffraction, Fraunhofer Diffraction, and Fourier Optics, as well as spatial filtering, computer-generated Holograms, Aberration Correction, Laser Modes, and much, much more (e.g., encoding information, the linear momentum, spin angular momentum, and orbital angular momentum of light beams).

The Future of Optics is Programmable

We are continuing a nationwide effort to develop a systemic understanding of the landscape of informal physics using an organizational theory perspective. We have collected surveys and interviews with facilitators, but this information is only from the perspective of the faculty or physics student leaders and does not tell us about the social dynamics within each program. Thus, to complement these data, we need to observe informal physics events as they occur. In this talk, we will discuss our strategy for visits to program sites to observe social interactions between program participants as well as programmatic details in action. We report on an initial site visit to a physics open house outreach event, where we took field-notes and conducted formal and informal interviews with participating personnel members. Here, we discuss findings from applying an organizational framework to the site visit data and challenges we encountered in the data collection process.

Premium content

Excerpts from an exploratory survey of units/dimensional analysis in introductory physics

Downloads

Next from AAPT SM 20

Model Rocket Engines

Similar lecture

Excerpts from an exploratory survey of units/dimensional analysis in introductory physics

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES