Saturday, October 2, 2010

Days 20-23

Okay, so clearly I didn’t get caught up on my blogging. Again, I’ll try to do a week in this post and then see if I can find time this weekend to do individual posts for this past week. Again, all links to the openers, lessons, assessments, and other stuff are contained in the class blog posts that are linked from each day.

Day 20
Today’s opener contained a problem about the world’s largest chocolate bar (used it for dimensional analysis), as well as some intercept questions. The lesson was an application of slope-intercept involving me, calories and a treadmill. I think the students appreciated the context, especially when I explained that the numbers were reasonably accurate, but I still feel like I’m doing too much of the work/thinking. I also gave them the background information for our next Skype session, with an engineer from NREL that’s working on a geothermal hvac system at a new IKEA store that’s going up in our city.

Day 21
Today’s opener contained another dimensional analysis problem, this time around texting and driving. Again, the students seemed interested in the context, and the fact that I can apparently find openers just about every day in the newspaper, but they still struggle mightily with actually completing them on their own. I’m wondering if perhaps I should start class by having them do jumping jacks instead.

The lesson for today involved weighing pennies and coming up with a linear equation to predict the weight based on the number of pennies (thanks to Frank who gave me the idea in a comment a while back). I had them place the pennies in a beaker before they weighed them so that I could manufacture a y-intercept other than zero, and I also made sure that each group had pennies that were either all pre-1982 or post-1982 (when the composition, and therefore the weight, changed).

This lesson went okay, but some of the groups collected such poor data that it was hard for them to get what I was hoping they would get. I think they more or less understood when we discussed it at the end, but I’m wondering if all the data collecting I’m having them do is perhaps getting in the way of their learning.

Day 22
We assessed on Graphing Linear Equations Using Intercepts today. Once again I thought I had prepared them well and had constructed a straightforward (and easy) assessment. Turns out I was wrong, as there was still a wide range of performance on this assessment. Some students are clearly not studying at all for these assessment but, even if that’s the case, I would hope they would still be doing better based on what we’ve done in class.

I thought the lesson today was pretty interesting, as we looked at – and graphed – data based on the current tax bracket rates, the rates proposed by the Obama administration, and the rates if the current tax policy expires. We worked with the data first, before I told them what it was. I then asked them to guess what the data represented, and one of my students did guess (surprising even himself). Again, though, I’m worrying that while I find the context of these investigations very interesting, I’m not sure they do. We then looked at some linear wind chill data as well.

Day 23
I’ve decided to try to make my openers take less time. For a while, at least, I’m removing the longer (and more interesting I think) problems in favor of problems that focus directly on the skills we’re learning. They just seem to be getting lost with the more in-depth problems, and then we also run out of time in class for our lessons, so I’m going to try this for a few weeks and see if it helps.

The lesson today gathered data on drop height versus bounce height for various types of balls (bouncy balls, tennis balls, etc.). This went okay, and they seemed to be getting the idea but, once again, at the end of the day I wonder if they would’ve gotten just as much or more out of it if I had just provided them the data instead of them collecting it.


  1. I wrestled with many of the same issues/challenges when I taught similar classes. I don't remember it really ever getting easier, it was always an uphill battle, but the kids always said afterward that they enjoyed the class and learned something. All this to say that you never really know how you're influencing or impacting them, but if you keep on keeping on you may be pleasantly surprised. Drops of water falling persistently eventually make a hole in stone. ;-)

    I'm struck by two things and I hope you wont be offended by these suggestions:

    (1) I think you're working too hard. You're posting to the class blog each day and writing here (and elsewhere) and it's going to catchup with you if it hasn't already. I don't see this as sustainable, particularly if you are interested in modeling for others that blogging not only adds value to what you do in class, it's a very doable activity.

    The summaries you post to the class blog don't really have to be written by you, do they? Couldn't it be a homework assignment for one student each night?

    Get a account where you can drop each day's files, include the date of the class as a prefix in the file name, and let the kids link to them from there. Alternatively you can display the contents of the box in a widget on the sidebar of the blog and the kids don't have to link to anything. Posting to the blog can be as easy as sending an email if you share the "post by email" address with them.

    (2) The other thing is, and you may already be doing this, instead of having each group of kids generate data in class have each group or each kid generate say 5 trials. Aggregate all the data from across the class. Of course there are times where you might want each group to generate their own full data set to illustrate the role variation and chance plays in the real world, but for what you're doing right now having the kids work with real world contextualized problems is valuable. Don't stop doing that, just find a way to distribute the load. If one kids messes up their data it opens the door to talk about outliers and then maybe you can invite Malcolm Gladwell to skype in. ;-)

  2. Darren - Thanks for the thoughts and the encouragement.

    1) I thought long and hard about whether to have the students post to the class blog (scribe posts). I decided against it primarily for two reasons. First and foremost, this is how I’m delivering their homework to them (as well as what we do in class), and I don’t think I can make them wait for when a student might have time to do that post that night. Second, after thinking about it for quite a while, I didn’t think it added that much value for the student doing it. Unlike a more descriptive scribe post (which I do think has value), this is more utilitarian and therefore I didn’t think it was worth it educationally to the students.

    I may try to implement some form of scribing second semester, but it would be in addition to what I post to the class blog each day.

    2) I’ve done the aggregating some, but not always. One of the problems is that the aggregating seems to take just as much time as collecting the data themselves. I’m not saying this in a negative way (although it is in a frustrated-I-wish-it-could-work--better way), but the students are so slow at doing things that any kind of investigation is taking longer than I would like, and not allowing enough time to actual work with the ideas at the end.

    Again, thanks for your thoughts – I appreciate it. Keep pushing.