Thursday, December 16, 2010

Another semester is over....

Well, another semester has come and gone and I have lived to tell about it. Seems like the exact same thing happened last semester: finals occur and then grading is finished and then I have to submit final grades. And someone is always unhappy. And I've found my unhappies already.

I heard this myself when I was a student but I don't think I really like it or believed it. "Its not the grade that matters." Over time I've grown to understand what this really means.

When I look at a chemistry text now I understand it in a much deeper way than when I was a student. I can cross-reference diagrams and find topics explained from different angles in different chapters. I never would have been able to do this as an undergraduate. It all came from years of experience and practice.

So the problem then is this: should we be coddling and comforting learners as they wade through the details of problem solving and reading the text by padding grades along the way? I don't know- I think in some ways it motivates people to give them positive feedback and encouragement. However, it certainly doesn't give them the real picture of their depth of understanding of the material. And- I'm not sure it accurately predicts how well they will perform in a more complex class (upper level)

I just gave a very hard final. I had students who normally get A grades fail the test. It was that hard. I took the questions primarily from the textbook test bank on a CD from the publisher. These are TOUGH questions. Most of them include answers that would seem logical if you don't understand the question on a very deep level. Of course, that wasn't the correct answer- only to be found through a detailed understanding of the calculations and logic behind each question. The test gave me some information about my students, however.

This test showed me which students really worked at understanding not only the math of chemistry but the conceptual grasp of big topics. One of the questions had them rank the boiling points of several compounds including covalent and ionic compounds. They were supposed to surmise that the strongest intermolecular forces and the strongest bonds lead to the highest boiling point. (The ionic compound always has the highest boiling point for this reason)  Even my best student missed this question. I'm trying to figure out how he missed this among many other more difficult conceptual problems on the test. I think it is because when we study covalent compounds I emphasize how hydrogen bonding is the strongest intermolecular force and causes the highest boiling point. What I usually don't emphasize here is that hydrogen bonding wouldn't create as high of a boiling point as ionic bonding.  So- for covalently bonded compounds ONLY,  hydrogen bonding would cause the greatest elevation of boiling point. Ionic compounds are in a whole different class altogether.

I hope my students take the experience of this excruciatingly difficult test as a motivating learning experience. This is but the first of many tough exams to come in their scientific or medical careers. It will prepare them to really study and think and examine what is important. It also teaches them there is no free ride. School is hard work.

I'll post this exam with the answers for my students next semester to chew on all semester. I plan to make the final more straighforward (with any luck I'll succeed- I had no idea this test would be this hard) I'm hoping that by chewing on the questions from this test students will be prepared to ask themselves and answer the really tough conceptual material.

Chemistry is no cake walk.