Showing posts with label teaching. Show all posts
Showing posts with label teaching. Show all posts

Wednesday, September 7, 2011

What is a Bridgehead Carbon anyway?

It's the start of a new school year and I am going to try to post a little more regularly.  Since it has been a while since I posted on a regular basis, I thought it would be a good idea to re-introduce this blog.

What is a Bridgehead Carbon anyway?  I teach undergraduate chemistry and my main area of interest is Organic Chemistry.  I chose the name "Bridgehead Carbons" partly because I have always liked the look of bicyclic compounds like norbornane.  You can think of Norbornane as being a cyclohexane (in pink) with a CH2 unit (in black)that acts as a bridge connecting the top and the bottom of the pink ring.  The carbons that connect the "main ring" to the "bridge" are the Bridgehead Carbons.



Another reason for choosing this name is that Bridgehead Carbons serve to connect different rings within the same molecule, and I intend to write about a variety of topics that I none the less feel are connected to my experience with chemistry and teaching.

So, what is this blog all about?  Stuff that interests me as a chemistry teacher, especially organic and bio-organic chemistry, cheminformatics, things that might be helpful to college students in general, and anything else that strikes my fancy.

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Wednesday, January 28, 2009

Monastic Musings: How can I be failing? - Unskilled and Unaware of It

A while back I found this article over at Researchblogging.com

Monastic Musings: How can I be failing? - Unskilled and Unaware of It In this post, Edith osb writes:
I noticed a surprising phenomenon last semester. Several first-year college students were getting consistently low scores on chapter quizzes - and they did not seem the least bit bothered or concerned about it. They were similarly unperturbed about scores below 60% on the first exam. When they received their mid-semester grade report, though, two of them came to see me, astounded to get such low grades. Their surprise was, of course, surprising to me: how could they possibly think that they were doing well when their quiz and exam scores were in the 50% to 60% range? They claimed that they were unaware that they were doing so poorly, and were somewhat angry that I had not "told them sooner."
A few years ago I had a student come to see me after final grades had been turned in.  The student had failed the class and was in tears, "Is there anything I can do to improve my grade?"  I was stunned, and explained that it was too late. Final Exams were the week before and the semester was over.  I gave 4 midterm exams and a Final Exam, this student had failed every one of them.  How could you not realize that you were failing the class?  Each of those exams was a clue that the student needed to get help.

I have always felt that college students should be treated like responsible adults.  It is their job to pay attention to their grades and get help when they need it. But reading Edith's post, and the article that inspired it, I am reminded of how easy it is to fool yourself.  I was not a particularly good student as an undergrad, and I often reassured myself that I would do better on the next exam - this did not tend to happen.  Realizing that you need help is difficult, and asking for it can be even harder still.

But there may be something else at work in addition to rationalizing and avoiding things that are difficult or uncomfortable.  In "Unskilled and Unaware of It: How Difficulties in Recognizing One's Own Incompetence Lead to Inflated Self-Assessments," Kruger and Dunning are interested in how people judge their own abilities. They looked at four different studies where the subject was given a task to complete, and then asked to predict how well they did.  

All of the subjects in all four studies tended to rate their own performance as above average! (How can everyone be above average?)  The subjects with the lowest scores thought that they had done much better that they really did.  The subjects with the best scores still rated themselves as above average, but generally below their actual scores. From this, the authors conclude:
We propose that those with limited knowledge in a
domain suffer a dual burden: Not only do they reach mistaken
conclusions and make regrettable errors, but their incompetence
robs them of the ability to realize it.
In the case of chemistry students, for example, this means that the students who don't know what they are doing also don't realize that they don't know what they are doing.  It is almost impossibe to correct your mistakes if you don't realize that you are making mistakes in the first place.

Consider American Idol.  If you have ever seen any of the audition shows you can see this in action.  The really awful contestants usually have no idea how bad they are, not a clue.  And they don't understand why the judges don't give them a ticket to Hollywood.  In contrast, a lot of the really good singers are much better at judging themselves reliably.  They know they sing well, but don't tend to over-estimate their ability.  They are often much better singers than they think they are, and seem a little surprised when the judges like their performance enough for a ticket to the next round in Hollywood.

Back to Edith's post.  She and some of the commenters suggest that some High School students - for a number of reasons - may not get trustworthy feedback on their academic skills, and because of that are not able to tell good work from bad.  They haven't learned to tell the difference. Or don't realize that it matters.

I have tended to downplay letter grades during the semester  - many things affect a student's final grade and one bad exam score can be offset by the remaining exams, quizzes and laboratory grades. I can't really predict a student's grade until everything has been graded.  I have also worked from the assumption that the student can tell that a exam grade below 70% means a D, which is close to getting an E (my school doesn't give F's, maybe the letter E is a little less judgemental) and realize that unless they do something about it they will be disappointed with their final grade. 

I think I may change that practice and start putting letter grades on exams and quizzes to help the low performing students learn to recognize unambiguously that they are not doing as well as they would like. I highly recommend reading both Edith's post (and the comments) as well as the original paper itself.

Monday, November 10, 2008

Ask Questions - Stepcase Lifehack

Ask Questions - Stepcase Lifehack

When I was an undergrad I tutored Organic Chemistry.  One of the students I tutored was a biology major and a friend - Kathy was also in the karate club,  but that's another story.  She was a challenging person for me to tutor - because she asked questions.  Specifically - "Why does that reaction happen?" and "How do you know that is the product?" and other inconvenient questions.  I could tell her the answers to her homework problems, but answering these questions took effort.

I'm grateful to her - she made me think.  And trying to answer her questions forced me to understand them myself.  Asking questions and trying to answer them is an important step in learning new things. Even asking yourself questions and trying to answer them yourself.  Don't be complacent!  Be curious!  Ask questions!

Sunday, September 7, 2008

Start of School

We're two weeks into the semester now and things are starting to settle into place again.  With the start of a new year there have been a bunch of changes, and of course not everything went smoothly.

First off, I have decided to try something new with my Organic Chemistry class. Lately I have been concerned that despite my best efforts, my students were not getting the most out of my lectures or the readings in the text. Using some student activities during lecture is something I have tried in the past, but I always drifted back to straight lecture. Over the summer I got two presents in my mail box:

  1. not one, but two copies of Organic Chemistry: A Guided Inquiry, which uses a POGIL approach

  2. a booklet on Using Pogil in the Classroom and Other Research Developments from last November's meeting of the Michigan College Chemistry Teachers Association

This seemed like too good an opportunity to miss. As a result, I am replacing my standard lecture format with POGIL. POGIL stands for Process-Oriented Guided Inquiry Learning and involves the students working in groups during class time, with me monitoring and guiding the groups when they have difficulties. The text is really more of a workbook which the students use during class that guides them through the process of learning each lesson. They need to have the book with them every day in class.

It is still a little early for me to tell, but the students seem to be adjusting – some better than others, but that is only to be expected. Of course, the students turned out to be the least of my problems in adopting POGIL. The second edition of Organic Chemistry: A Guided Inquiry, the POGIL text I am using, came out over the summer. When I went to our bookstore manager in July to ask about switching texts he told me there wouldn't be a problem and we should have the books before class started. Ha!

As it turns out, the publisher was out of stock and didn't expect more until Sept 5 – two weeks into the semester. This is at minimum a nuisance, but if the students NEED to have the book with them in class every day to do the lessons it makes it difficult to stick to a schedule. My bookstore manager was very helpful, he was able to get the first few sections of the book copied for me by the first day of class – so we were covered with about two weeks worth of class activities. The author, Andrei Straumanis, has a pretty active listserve on using his book and the POGIL system. He got permission to post pdf's of the first few weeks worth of the book on his web site.

Friday the bookstore called to say the books were in. Hurray!