Posted in Education, Physical Chemistry, Science Education, Spectroscopy

What is pchem?

Pchem is short for Physical Chemistry. It is hated by all. It is SO bad (the audience asks, “How bad is it?”), that it has it’s own bumper sticker!
Why is pchem so mistreated?
Like a scientific tax accountant, a P-chemist worries about the energetic balance sheet, the gains and losses of energy, the ratio of usable to unusable energy. We pull the thread through all states of matter – liquid, solid, gas, plasma, elastic, plastic, glass, etc.
My favorite subsection of pchem is symmetry and spectroscopy. Spectroscopy is the study of light interacting with matter. And symmetry is used to decipher these interactions. There is no better example of the mathematical beauty of our universe than the unexpected explanatory power of group theory as it applies to absorption and emission of light.
Fireworks, hair dye, crayons, ink, glow sticks, lightning bugs, and all the rest can be understood through pchem – specifically my field of spectroscopy.
There is much more to pchem. If you have made it this far, then you are truly curious. Therefore, I give you the table of contents to a typical pchem textbook. (You will have to “Look Inside” at the Amazon site to view the TOC.)
And, I ask you to share and subscribe to this blog. Comment below with suggestions for posts.
Posted in Education

The #WAR on Cramming

Homework serves several purposes in academic pursuits.  It guides the students through a subset of material the professor deems important. It forshadows the examination. It serves as a scaffold for the student to assist the building of their body of knowledge in the topic.

It should not be “busy work” because this wastes valuable student time.  It should not create a protracted grading burden on the professor, because immediate feedback is best for the student when learning new material.

Therefore, I am exploring the following with positive initial results.  I use multiple choice homework problems, because these are automatically graded online by the Blackboard learning system.  These assignments fullfil the purposes of forshadowing the exam, and guide the student through the appropriate material.

The negative aspect of this is the natural focus of the student on “which letter is the correct answer”.  I do NOT care about which letter they check.  I want them struggling with the problems, building their body of knowledge, and internalizing the concepts and theories.

Therefore, I have changed the grading rubric to punish simply getting the correct letters in one setting.  The only way to achieve a perfect score on the homework is to do the following:

1. Take the homework exam multiple times over several days showing improvement towards the eventual score of 100%.

One can EASILY fake this, which is why it will only be 5 to 10% of the weighted average of a given course.  But instead of faking this apparent activity, consider actively using the process that I am encouraging.

So to my students, I give the following advice:

  • As soon as the homework test is made available, log in and take it cold.  Give your best guess on the vocabulary.  Estimate the numerical answers.  Do your best to ace the test “cold” without knowing the material.
  • Then, download the pdf version of the homework test. Over the next few days, work the problems in your “problems composition book” (hint, make one of these).  Work similar problems from the back of the text.  Work similar problems from the Internet.  Evaluate why the right answers are right.
  • Log back into Blackboard.  Take the homework test again.  If you do not make 100%, then work the ones that confuse you.  Ask about them in class.  Get with your study group.  If you are convinced your answers are right, perhaps there is an error in the homework test.  Ask about it in class.
  • Finally, you should be able to achieve a 100% on the homework test, AND THE RECORD OF YOUR MULTIPLE TESTS ON BLACKBOARD will be evidence that you deserve a 100% for PARTICIPATING in the homework assignment.

I welcome your constructive input.