Archive for October 9th, 2006

Pet peeves: Preforming an analysis

Monday, October 9th, 2006

Here’s one of my pet peeves – “preformed”. I routinely have students tell me things like

The standardization of 0.1 M base was preformed using the primary standard grade KHP.

I’m sure the student didn’t mold the base into a predeterimined shape before doing the analysis. Perhaps this student meant that they “performed” the standardization?

Of course, even the word “perform” in a description of what you’re doing in a lab is never actually necessary – unless you’re actually performing your experiment before a live studio audience. What’s wrong with saying sometihng like this?

The 0.1M NaOH solution was standardized by titrating against primary standard grade KHP.

Down to their level

Monday, October 9th, 2006

It’s always interesting to know what your students are actually thinking. I have to admit, though, that sometimes I would really rather not know. Take this example, buried in the comments from a set of student surveys from a past semester:

[Rick] needs to come down to our level.

You might expect to hear comments like this from students in, say, sophomore level chemical engineering thermodynamics. Heck, I still have nightmares about that course. The comment above, though, was left for me by one of my introductory chemistry students. Introductory chemistry is the lowest-level chemistry course we offer – roughly on par with a high school course. It’s the lowest-level science course with a lab that we teach.

How low a level are we talking here? Here’s one of the questions from this course’s first test.

Determine the length of the line based on the ruler drawn below.
[image of a ruler and a line]

(Why ask about a ruler in an intro chemistry class? We discuss reading of measuring devices like rulers, graduated cylinders, and balances early on in the course – otherwise the students couldn’t really do much in the course’s lab. The ruler itself is mostly meant to connect a familiar measurement – what adult has never used a ruler? – to more unfamiliar devices like graduated cylinders and balances.)

I’m at a loss. Education isn’t like the limbo. It’s not about how low you can go. And, with this particular course, it’s not as if I can “come down” any more. At some point, the student has got to climb.