The Physics Problem and Standards-Based GradingPosted: March 9, 2011
Inspired by the Standards-Based Grading Borg, I am slowly putting together the picture of my own potential SBG implementation. One thing which I still have yet to sort out is how does the typical physics problem fit into a Standards-Based Grading implementation? Or to ask a slightly different question..
How does one assess a typical physics problem in a Standards-Based Grading implementation?
Note: I have not read any of the SBG literature and my exposure to SBG comes entirely from the SBG blog Borg so my questions arise from the implementations with which I am familiar.
Second note: This post is meant to start a conversation that will hopefully help me sort out how I can make Physics problems and SBG ideals happily co-exist in a course. I am not tied to the exams or any other part of my colleagues’ sections of the same intro courses that I teach, but in the end I have to show that my students are able to solve the same kind of problems that show up on my colleagues exams.
The Physics problem
I would argue, that in the typical university physics course, the physics problem is the most commonly used assessment item. They are assigned for homework, they show up on exams, students do tons of end-of-the-chapter problems to study for exams, and most college instructors use them as the primary method to teach new concepts. My intro-level courses are far from traditional from the point of view of how class time is spent (pre-lecture reading assignments, clicker questions using peer instruction, strong conceptual emphasis, lots of group work), but I still use a traditional assessment system. My students work problems on their homework assignments, in their quizzes and on their exams. Approximately 1/3 of the marks on my exams come from problems.
I am being overly generous and calling what is usually just an exercise a problem. A “physics problem” is something which requires actual problem solving on the part of the person attempting it and not just some algorithmic pattern matching based on previously seen or completed exercises. But let’s not get hung up on this distinction. Let’s just say that a physics problem is something which requires some or all of the following skills:
- Identifying relevant physics concepts and correctly applying those concepts to the situation discussed in the problem statement;
- Building a model;
- Keeping track of units;
- Procedural/mathematical execution;
- Respecting significant figure rules;
- Making and justifying estimates;
- Checking the reasonableness of answers;
- Translation of representation (for example between graphical, words, formulas, motion diagrams and/or pictorial);
- Writing up clear, coherent and systematic solutions.
I’m sure folks could come up with many others, but those are the skills that my brainstorm yielded.
Assessing a Physics problem in SBG
Let’s say that for various reasons (administration, the rest of my department, transfer status of the course to larger universities, etc), that I must have my students tackle numerous Physics problems during a course and these are problems which consistently require as many of the above-listed skills as possible. How do I assess these problems in SBG?
My colleagues would argue that most of those above-mentioned skills used when solving a problem are very important skills for a person continuing on in physics and that we should “teach those skills” to our students. I could write-up the above mentioned skills as standards. I could then have one of two primary strategies: assess most of these standards individually or assess multiple standards on each problem.
The problem with the individually assessed standards is that they are all part of the problem-solving package and assessing each of them individually doesn’t assess the coherent whole of problem solving.
With assessing multiple standards on each problem, not every standard can be present at the same level. And for some of these standards it seems as if trying to assess them from a tiny piece of an individual problem would be the same as assessing how accurate of a basketball shot somebody has based on seeing them shoot only a single free-throw.
Incorporating Physics problems into an SBG-assessed course
Now let’s say that the above is still true, I must have my students tackle Physics problems. But, for whatever reason, I can’t/don’t/won’t come up with a good way to assess them. But I want to be true to SBG and not have to just tack on 10% for homework problems or just give them an exam at the end that has problems and is worth a certain fraction of their mark while all their SBG-assessed standards are worth the remaining fraction of the their marks. I just want their grade to be some sensible reflection of their scores from the assessed standards.
How do I incorporate Physics problems into my course in this case?
A couple more quick questions
- If I am using problems to assess multiple problem-solving standards at a time, how do they earn the “exceeds expectations” levels (4/4 or 10/10) on their standards?
- The common practice in SBG seems to be to make the standard being tested nice and explicit. But having a standard like “identify relevant physics concepts” means that you have to avoid making the conceptual standards explicit with a problem. Is that good, bad, or does it matter?