Welcome back y'all! The beginning of the year is so exciting! I feel energized and look forward to meeting my new students. My classroom is neat and tidy, even my lab is organized and clean. And then, it begins. We do a lab, the students get to experience chemistry through some hands-on work, and I need to see what they have learned. Oh, the lab reports! This is my least favorite part of teaching! It was difficult for me to be consistent which of course led to rubrics.
I began using rubrics, but I did not like how they were written. Students who did well according to the rubric did not neccesarily do well according to what I thought. This, of course, led to re-writing the rubrics. Now, I am writing rubrics for the new labs I am writing and I am nervous all over again.
Have you ever used a rubric you liked? Did you ever use a rubric someone else wrote? Did you ever compare how you used it to how another teacher used it? We are trying to be consistent in our course and I am wondering if having a rubric will truly help maintain that consistency. Let us know what you think!
Lowell Thomson recently shared some logistical tips to the grading. You may want to check out his blog also.
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Comments 2
Simplified rubric
I changed to a very simplified rubric about two years ago. All of my labs are now worth the same amount: 16 points. Their grade is determined by four categories: scientific knowledge, experimentation, observations, and analysis. Each category recieves a score of 1-4 (unless a student leaves a section of the lab blank that might give a 0). This way I can have as many or as few questions as necessary and not worry about how much each question would be worth. This rubric works well for the short one-day labs that I use for Chemistry and Physics, but may need modification for extended labs. You can also use a multiplier to get a final grade if you want them worth more. For make-up work, I provide students with sample data and their grade is only Scientific knowledge and Analysis with the total doubled to create the same total possible points. The categories are generally broken down as follows (not an exhaustive list):
Scientific knowledge - answers general questions correctly about background, theory, and/or procedure; uses appropriate formulas in calculations;
Experimentation - uses proper protective equipment; uses correct equipment; follows safety procedures; percentage error within a reasonable range; in some labs this may also include performing more trials or revising their hypothesis/experiment;
Observations - fills in data tables/graphs completely; uses sufficient detail; uses proper estimation in measurements; data matches expected results (not describing copper nitrate solution as a black precipitate for example);
Analysis - correctly answers extension questions about the data set; correctly calculates formulas used in the experiment; uses appropriate number of significant figures;
RE: Simplified
Thank you for your thoughts, John! I like this idea of going simple as it is very difficult to assign specific points to questions. I will give this some thought as I continue to think about my own rubrics for this new lab manual.