# Critical Thinking Assessment

Those of us teaching physics have made a lot of changes this year. One major change is a focus on depth of understanding and critical thinking, which results in fewer topics covered. While I have qualitative evidence through formative assessments that students this year have developed stronger critical thinking and long-chains-of-reasoning skills, I’ve been bothered that I don’t have a summative assessment to measure this. Ideally, I would like an Force Concept Inventory pre-test/post-test equivalent for critical thinking. I’ve bookmarked the College and Work Readiness Assessment (CWRA), but that isn’t an assessment that I can administer to my own class. If you know of another, please let me know!

Here is my reading passage, observation procedure, and guiding questions:

The students did quite well connecting what they read about diffraction to what they observed to what they already knew about interference. Here are some of my favorite student comments.

The black parts are shadows, I think we see them because the light is being destructed?

In order to have constructive interference, one ray must travel one wavelength further than the first.

The blue filter causes the lines to be closer than that of the red filer because blue has a shorter wavelength and when it travels to the plate, it forms more concentric circles. Thus, there are more intersection of circles and more lines formed.

and my favorite (written without any guiding questions):

… It’s like light beats.

I also had some really creative explanations of the interference pattern. Students mentioned internal reflection in our eyes as well as lens effects due to the slits.

Students commented that this was unlike any final exam they had previously taken. In fact, several students in one class didn’t want to leave until they were satisfied they had a complete explanation. It certainly seemed more worthwhile than giving students a list of equations and a set of problems with numbers for them to plug in on their calculator. I think there is a kernel of a good idea here, but I need to develop it more. In my largest class, it was hard to manage since I had to interact with each student during the assessment, read their explanations, and give them the appropriate guiding questions. Sometimes this required me asking my own clarification questions and the ensuing discussion could be overheard by other students. If you have tried anything like this, please share your experience!

Last year, myself and a colleague jumped into the standards-based grading pool with both feet with our honors-level physics class. We appreciated that homework was for practice and should not be graded. I was very excited about this departure from the traditional model of checking homework every day and keeping track of completed homework and absences which wasted valuable class time.

At first, students attempted their homework as assigned. However, before too long, it was apparent that a vast majority of students were not attempting the homework problems before we were to whiteboard them in class. After one particularly ineffective whiteboard session, due to a vast majority of students being unprepared, I attempted to use that experience to illustrate the importance of using the homework problems as practice.

Why did this happen? Did we fail to explain our standards-based grading philosophy? No, I think students appreciated the importance of the learning activities. Students were engaged in learning activities such as labs even though they were not graded. Were the homework problems unnecessary busywork? No, this class moves at a fast pace and, for a vast majority of students, practice outside of class is essential. Students weren’t attempting just the problems they felt they needed to practice; they weren’t attempting any problems.

After this ineffective whiteboard session, a few students with whom I had stronger relationships made a point to talk to me about why they hadn’t attempted their homework. All of them said that they appreciated that they needed to practice these problems. All of them said that they knew that they wouldn’t be able to effectively whiteboard the problems without having at least attempted the homework. All of them knew that eventually they would need to practice in order to do well on the summative assessments. However, all of them also explained that not doing their homework was a conscious decision. They explained that they get home late due to soccer/marching band/play practice. They explained that they have more homework assigned then they can possibly complete in a night (another issue to address). If they don’t complete their math/social studies/other science homework, they lose points, their grade is impacted, their GPA is affected. They believe the only logical choice is not to do their physics homework.

When other classes assign points to homework, overloaded students that are grade-centric won’t do homework that isn’t assigned points.

What did we do? We started grading the homework the next semester. We reconciled this change by framing homework as both a learning activity and summative assessment. We continued to whiteboard homework problems (learning activity), but, by the end of the unit, students were required to submit their homework solutions via WebAssign (summative assessment). We used WebAssign since we were able to randomize the numerical values in otherwise identical problems. This allowed students to collaborate but not copy final values.

We haven’t satisfactorily solved the problem of homework. Our current approach is simply the best idea we have at the moment. Over time, this issue may be mitigated as more and more classes in our high school adopt standards-based grading and fewer and fewer teachers grade homework.

If you’ve encountered this problem and are taking another approach, please share! We can always make a change next semester!

# I Like Reading Lab Reports

When I first started teaching, I loathed grading lab reports. I had a seemingly never-ending pile of papers almost a foot tall sitting on the front, right-hand corner of my desk glaring at me with that look of “we’re not going anywhere, you know.”