The Modeling Framework for Experimental Physics ("the Modeling Framework") is one way to describe the nonlinear, recursive process through which experimental physicists develop, use, and refine models and apparatus. In the context of upper-division physics lab courses, the Modeling Framework has been developed to characterize students' model-based reasoning and to inform development of instructional lab environments that engage students in the practice of modeling. A diagram of the Modeling Framework is provided below (click to enlarge for readability).

## Poster Sized Modeling Framework for Classrooms

## Models and Modeling

*Models* are abstract representations of the real world. A well-defined model is associated with a target system or phenomenon of interest, and the model can be used for either explanatory and/or predictive purposes. Importantly, models contain simplifying assumptions that yield tractable mathematical, graphical, and other representations. These assumptions limit the applicability of a model. Moreover, model limitations give rise to the possibility of model refinement by eliminating some assumptions. The iterative improvement of models to make them more accurate and sophisticated is one path in the process of modeling.

*Modeling* is the process through which models and systems are brought into better agreement, either by refining the model or the target system itself. The Modeling Framework subdivides the target system into two parts, each with its own corresponding model: the physical system and the measurement system. This subdivision reflects the fact that experimental physicists often operate measurement equipment in regimes where the limitations of that equipment become important.

## Why is the Modeling Framework Important?

The Modeling Framework is connected to national and local learning goals for undergraduate physics laboratory courses. At the national level, the American Association of Physics Teachers recently released "AAPT Recommendations for the Undergraduate Physics Laboratory Curriculum." This document identifies modeling as a major focus area for learning outcomes for lab courses. Similarly, on a more local scale, modeling was also identified as an important learning goal by instructors in the CU Boulder Department of Physics. The Modeling Framework was designed in part to support instructors in thinking about what types of processes support student engagement in the practice of modeling, both nationally and here at CU Boulder. In addition to informing the design and/or transformation of laboratory courses, the Modeling Framework provides physics education researchers with a tool for characterizing and assessing students’ performance of experimental physics activities.

## Applications of the Modeling Framework

Our initial applications of the Modeling Framework have focused on electronics and optics courses and activities. At CU Boulder, we have transformed the Electronics Lab and the Advanced Lab courses, typically taken by physics majors during their third and fourth year of instruction, respectively. In addition, we have demonstrated that there is a good mapping between the Modeling Framework and students’ process of completing optics and electronics activities. Specifically, we have used the framework to describe students' approaches to using a photodetector to characterize the power output of an LED and their approaches to repairing a malfunctioing cascade amplifier circuit. Ongoing work is focused on development of assessments that instructors can use to measure growth in students’ ability to use model-based reasoning to complete experimental physics tasks.

## Publications

"Using think-aloud interview to characterise model-based reasoning in electronics for a labaratory course assesment"

Laura Rios, Dimitri R. Dounas-Frazer, and H. J. Lewandowski, Phys. Rev. Phys. Educ. Res. **15**, 010140 (2018)

"Instructor perspectives on iteration during upper-division optics lab activities"

Dimitri R. Dounas-Frazer, Jacob T. Stanley, and H. J. Lewandowski, Proceedings of the Physics Education Research Conference, p. 116-119 (2018)

"Using lab notebooks to examine students' engagment in modeling in an upper-divion electronics lab course"

Jacob T. Stanley, Weifeng Su, and H. J. Lewandowski, Phys. Rev. Phys. Educ. Res. **13**, 020127 (2017)

"Investigating the role of model-based reasoning while troubleshooting an electric circuit"

Dimitri R. Dounas-Frazer, Kevin L. Van De Bogart, MacKenzie R. Stetzer, and H. J. Lewandowski, **Editor's Suggestion **in Phys. Rev. Phys. Educ. Res. **12**, 010137 (2016)

"The role of modeling in troubleshooting: an example from electronics"

Dimitri R. Dounas-Frazer, Kevin L. Van De Bogart, MacKenzie R. Stetzer, and H. J. Lewandowski, Proceedings of the Physics Education Research Conference, p. 103-106 (2015)

"Redesigning a junior-level electronics course to support engagement in scientific practices"

H. J. Lewandowski and Noah Finkelstein, Proceedings of the Physics Education Research Conference, p. 191-194 (2015)

"Model-Based Reasoning in the Upper-Division Physics Laboratory: Framework and Initial Results"

Benjamin M. Zwickl, Dehui Hu, Noah Finkelstein, and H. J. Lewandowski, Phys. Rev. ST Phys. Educ. Res. **11**, 020113 (2015)

"Incorporating learning goals about modeling into an upper-division physics laboratory experiment"

Benjamin M. Zwickl, Noah Finkelstein, and H. J. Lewandowski, Am. J. Phys. **82**, 876 (2014)

"The Process of Transforming an Advanced Lab Course: Goals, Curriculum, and Assessments"

Benjamin M. Zwickl, Noah Finkelstein, and H. J. Lewandowski, Am. J. Phys. 81, 63 (2013)

"Transforming the advanced lab: Part I - Learning goals"

Benjamin Zwickl, Noah Finkelstein, and H. J. Lewandowski, AIP Conference Proceedings **1413**, 391 (2012)