Which optics and waves research-based assessment should I use in my class?

posted April 10, 2021
by Adrian Madsen, Sarah B. McKagan and Eleanor C. Sayre

This recommendation initially appeared as an article in the American Journal of Physics:  A. Madsen, S. B. McKagan and E. C. Sayre, Resource Letter RBAI-1: Research-Based Assessment Instruments in Physics and Astronomy, Am. J. Phys. 85, 4 (2017).

There is one assessment of geometrical optics, the Four Tier Geometrical Optics Test (FTGOT) (Kaltakci 2012). There are four RBAIs about waves, three for introductory-level courses, the Mechanical Wave Conceptual Survey (MWCS) (Tongchai et al. 2009), the Mechanical Wave Conceptual Survey 2 (MWCS-2) (Barniol and Zavala 2016), the Wave Diagnostic Test (WDT) (Wittmann 1998), and one for upper-level courses, the Wave Concept Inventory (WCI) (Roedel 1998). An overview of the assessments is given in Table 1. 

Geometrical optics assessment

Four Tier Geometrical Optics Test (FTGOT)

The Four Tier Geometrical Optics Test (FTGOT) (Kaltakci 2012) is a pre/post conceptual assessment of geometrical optics for introductory college courses (Table 1). The questions on the FTGOT ask about observing oneself and observing others with plane mirrors, spherical mirrors, and lenses. The FTGOT has “four tiers” of sub-questions for each main question. These ask students to answer a multiple-choice content question, rate their confidence in their answer, indicate their reasoning (also multiple-choice), and then rate their confidence in their reasoning. The test structure can give instructors more confidence that a correct answer to the content question does actually indicate understanding by the student. The FTGOT questions were developed based on a literature review, the devel- opers experience teaching these topics and open-ended inter- views with students. The FTGOT was developed in Turkey. Use the FTGOT if you want to assess your students’ understanding of geometrical optics concepts at the introductory level.

Table 1. Waves and optics research-based assessment instruments. 

Title Content Intended Population Research Validation Purpose 

Optics

Plane mirrors, spherical mirrors, lenses

Intro college Silver

To assess misconceptions in geometric optics.

Waves

Mechanical waves, wave propagation, wave superposition, wave reflection, standing waves

Intro college, intermediate, high school

Silver

To identify students’ alternative conceptions about mechanical waves before instruction and evaluate the effectiveness of instruction at the end of a course.

 

Mechanical waves, wave propagation, wave superposition, wave reflection, standing waves

Intro college, intermediate, high school

Silver

To assess students’ understanding of basic wave concepts using a standard multiple- choice questions format.

Waves

Intro college, intermediate, high school

Silver

To understand students’ thinking about basic wave concepts.

Visualization of waves, mathematical depiction of wave, wave definitions

Upper-level

Bronze

To assess students’ understanding of wave phenomena in an integrated upper-division engineering course on electronic and electromagnetic topics.

Introductory waves assessments

There are four RBAIs about waves, three for introductory-level courses, the Mechanical Wave Conceptual Survey (MWCS) (Tongchai et al. 2009), the Mechanical Wave Conceptual Survey 2 (MWCS-2) (Barniol and Zavala 2016), the Wave Diagnostic Test (WDT) (Wittmann 1998). 

Mechanical Wave Conceptual Survey (MWCS)

The Mechanical Wave Conceptual Survey (MWCS) (Tongchai et al. 2009) is a multiple-choice pre/post assessment of basic wave concepts covered in introductory courses, though it has also been tested with high school students. The MWCS has four sub- topics including propagation, superposition, reflection, and standing waves. Several questions have more than 5 answer options and several questions ask students about their reasoning in addition to their answer (as a two part question). Because of this non-standard question format, a standard Scantron answer sheet would not work. The questions were created based on the open-ended questions from the WDT. The MWCS was developed in Thailand and Australia.

Mechanical Wave Conceptual Survey (MWCS-2)

The Mechanical Wave Conceptual Survey 2  (MWCS-2) (Barniol and Zavala 2016) is a modification of the MWCS. The MWCS-2 is modified to make MWCS questions into the standard multiple-choice formats with five answer options each. The developers of the MWCS-2 made changes to the wording of questions as well as adding and removing answer choices for some questions. Further, for the MWCS questions with two parts (answer and reasoning), the MWCS-2 combines the answer and reasoning together, so that these questions just have five standard answer choices. Besides the modifications discussed above, the content tested on the MWCS and MWCS-2 is the same. The MWCS-2 was developed in Mexico.

Wave Diagnostic Test (WDT) 

The Wave Diagnostic Test (WDT) (Wittmann 1998) has both free-response and multiple-choice questions about mechanical and sound waves topics covered in a typical introductory physics course. The main purpose of the WDT is to learn about students’ thinking about waves, not to compare stu- dents’ scores to a baseline. The WDT elicits rich and varied responses from students that show what they believe about waves and why. This makes the WDT very useful as a benchmark, and allows you to more accurately tailor your instruction to the incoming beliefs of your students. Because the WDT is meant to understand students’ thinking, it is not scored. There are two parts to the WDT, and students should complete and turn in part 1 before completing part 2.

The questions on the WDT and MWCS are very similar, since the MWCS was developed from the WDT, but all the questions on the MWCS are multiple-choice, whereas many of the questions on the WDT are free-response. The MWCS is scored in the standard way (% correct), whereas the WDT is meant to be used to understand your students’ ideas, and therefore is not scored. 

Recommendations for choosing an introductory waves assessment

Use the MWCS-2 to assess students’ understanding of mechanical waves in introductory physics courses if you want to compare students’ scores before and after your course with an assessment that is quick and easy to score. Use the WDT for introductory courses if you want to understand students thinking about mechanical waves in a more in-depth way

Upper-level waves assessment

Wave Concept Inventory (WCI) 

The Wave Concept Inventory (WCI) (Roedel 1998) is a multiple- choice pre/post-assessment of upper-level wave phenomenon content including visualization of waves, mathematical depiction of waves, and wave definitions. It was designed to assess the effectiveness of an integrated electrical engineer- ing course covering quantum mechanics and Schrödinger’s wave equation as well as Maxwell’s wave equations and their application to the propagation of electromagnetic waves, though could also be appropriate for an upper- division physics course. Some of the questions have more than one correct answer, which more thoroughly assess students understanding of the content. There are no calculational questions on the WCI, but students are asked about mathematical equations (e.g., which linear partial differential equation can be used to model wave propagation). The WCI questions were developed by the instructors of an integrated electrical engineering course.

The concepts covered on the WCI are for upper-level engineering courses, though could also be used at the upper-level in a physics department. The WDT and MWCS are meant for introductory courses, so the content and level of these tests are very different. Use the WCI for your upper-level course if the content on the test aligns with what you teach in your class.