Maybe I shouldn't have started this blog now, not with everything that's been going on.

I’m posting relatively early today because we have an “IT-Infused Curriculum Workshop-Seminar” from 1 to 5pm later, and I’m not sure if I have the time to return to the faculty room after that.

Continuing my discussion about my mechanics lab class last Wednesday, this is the first time I used the spark timer that I had to buy and ordered two terms ago.

David had already used it last term in his class though. Some of our students from last year, who were in the chemistry lab next door, were surprised at the set-up we were using. After all, they had to use an inclined ramp, a ball bearing, a piece of chalk, a meter stick and at least one celphone timer (but preferably a dozen).

For this set up a cart is attached to a meter long strip of paper that passes through the spark timer. As the cart (a Lego Mindstorm simple four-wheeled attachment) rolled down the ramp, the spark timer marked the strip of paper at regular chronological intervals.

Since it was assumed that the cart would accelerate due to gravity the further it rolled, the marks on the paper became further apart.

During the first trials (there were, after all, only four groups) some students complained that the marks of the paper were not visible. Looking at the small round carbon paper over which the strip of paper was supposed to be placed, I saw that it had a couple of areas almost burned through, because the paper always seemed to start and stop at that point.

I had to turn it a little so that it would start at a different spot. The results were a bit more discernable, but not enough for the second class in the afternoon. For them we had to bring out a completely new carbon paper.

Here is also where the idea about the students reading the procedure before the experiment would seem to profit them, because almost all groups took the entire three hour period just finishing their measurements and their computations.

And to think that this experiment, all the work is at the start and measurements and computations take up the other 95%. What more for the other experiments?

I’m thinking of returning to my previous policy of reminding the students at the start about what they are supposed to do for the experiment, along with the usual modifications that I have for the procedures and the data tables.

Like for the new version of the manual, making the bar graph of position versus time from the cut up strip of paper that they used was taken out. We didn’t have that instruction when we first used the new manual two terms ago, and I didn’t notice until now.

I also told the class that given the leader and secretary assignments, part of their group grade would now be based on performance demeanor, where I go around looking at how they perform the experiment, and grade the members (particularly the leader and secretary) accordingly. That would hopefully get rid of the consistent slackers.

Just a couple more things I have to say about the lab, but it will have to wait until tomorrow. Class dismissed.