By Stacy Palen
In the last post, I explained that a rubric is a written explanation of your expectations and intentions, and why they are useful in clarifying expectations and simplifying grading. I divide my grading rubrics into two parts: a part that is applied separately to each question, and “collective marks” that apply to the whole assignment. In this blog post, I explain how I use the first part of the rubric to guide me as I assess content knowledge.
I assign short-answer homework problems, which sometimes include math, each week. I also assign one in-class hands-on exercise each week. Students in my class take two exams each semester, each of which involves a variety of problem types. It’s useful for me to separate the content knowledge from the over-arching skills, like writing complete sentences, including all the details of a graph, and so on.
For example, I often grade short-answer homework questions out of 3 points, using this very basic rubric:
The answer to each question will be graded out of three points:
3: Excellent: Exactly right! Well done!
2: Satisfactory: Well, you kind of had the right idea...
1: Fairly Bad: You wrote something down.
0: Not attempted
This rubric is tightly focused on the content of the answer to this question. There is nothing here about complete sentences, units, handwriting, or even clarity of thought. This is very fast to do, and by the time I get to the bottom of a stack of 120 assignments, I’ve seen all the answers and recognize on sight whether this particular answer should get a 2 or a 3. I will use this rubric for short-answer and mathematical answers, and sometimes for sketches.
I need a more detailed rubric for some pictures, and all graphs. It is appropriate to have more points available for these types of answers than for the answers to short-answer questions because it takes a lot of time to produce a high quality sketch or graph. Personally, I care deeply about graphs because I place graph-reading near the top of all the life skills a student might learn in an introductory science class. An educated person needs to know how to read a graph, if only so they can plan for retirement! I have a separate rubric for graphs. This rubric helps to remind students about the parts of a graph that matter:
For each graph, you will be graded out of 5 points:
5: Excellent: The graph is clear an dwell-presented. Axes are labeled with units, and there is a legend if more than one thing is plotted.
4: Good: The line fits are slightly in error and don't fit the data as well as they could. Constraints have not been applied correctly; some graphs must have lines that pass through 0,0, for example.
3: Satisfactory: The data are plotted correctly but the line fit is inappropriate or missing. Alternatively, there is a line with no data to constrain it.
2: Insufficient: Major or many components are missing, such as an axis or axis label.
1: Very Bad: Seriously? You wasted my time turning this in?
By using these rubrics to grade for content, I free myself from having to agonize over how many points to give for an answer that is mostly correct but poorly worded. I can give the benefit of the doubt for answers that seem right but leave me not entirely certain that I know what they meant. I can give students a little bit of credit, even if I can’t completely read what they have written. And I don’t have to worry here about spelling, units, or grammar. I have collective marks for all those issues, which I’ll talk about in the next post.