Heather M. Whitney

Moving

Heather Whitney — Mon, 26 Dec 2011 23:09:03 +0000

I’m moving. Just this blog, that is. The days between Christmas and the spring semester starting up again tend to be a time that I fiddle with web stuff. I decided to create a special place for my blog, which you’ll now find at http://convergediverge.com (and will redirect automatically to here.) Update your feed readers! (And give me a shoutout if you know how to export Disqus comments. So far, they’re lost in the ether.)

Heathermwhitney.com will remain in place, but will become more of a launch page with other more static items.

[Image Creative Commons licensed / Flickr user KDavidClark]

What is that, a hup?

Heather Whitney — Sat, 22 Oct 2011 03:55:22 +0000

Today in non-major, algebra-based physics we went over the fairly classic problem of determining which will win a race down a hill, a sliding block or a hoop, cylinder, or solid sphere? I like working through this problem because it’s a great way to show students the value of not plugging in numbers too early, but rather let the equations play out so that you whittle the problem down into what really affects the difference in answers between all the options. It’s also a nice example of thinking about a distribution of initial energy; in this case, the object will go slower when some of its potential energy gets converted into rotational kinetic energy. The object that has the least amount of energy going into rotation (or none, in the case of the sliding block) will have the most available to go into its translational kinetic energy. And that will be determined by the objects’ moments of inertia.

Everything was proceeding like it has in years past when I’ve taught this section, but then a question came up: should we account for friction? One student in particular noted that he thought that there had to be friction present in the rolling objects’ case, even if you said the sliding part was frictionless. And for the conservation of energy equation to play out, you really did need to include it.

I’ve got some ideas, but I want to ask you all – what do you think? Part of me feels that this is connected to an oddity I see in a lot of my non-majors, in that they are always wanting to think about friction, air resistance, etc. (Compare that to my physics majors, who in today’s Matlab class were very pleased to not account for air resistance in a model we coded for hitting a baseball a certain distance.) I’ve been thinking a lot about why my non-major students are so attached to the ideas of friction and drag. In class we talk a lot about setting up models, adding in additional factors as we get more and more specific with the model. But this year’s class especially isn’t happy with the discussion. They ask, “if we live in a world with friction, why would we even bother to ignore it?” I was talking with a colleague in the health sciences, and he said that the students (many of them the same ones I have in my class) ask essentially the same thing for some models he talks about. So at the very least, their questions like this aren’t limited to physics.

But to get back to the original question, do we need to include rolling friction in the analysis of which rotating object will go down the ramp the fastest?

*”hup” is how my college physics professor pronounced “hoop” when we covered this. He said, memorably, “what is that, a hup?” and I almost always dissolve into giggles thinking about it even now. I guess you had to be there.

[Image Creative Commons licensed / Flickr user phonogalerie.com]

Getting students to read ahead

Heather Whitney — Mon, 26 Sep 2011 14:00:04 +0000

In my last post, I talked about how students were drawing very complicated free body diagrams (FBDs) in class. Not even stick figures, they were drawing extremely complicated figures with gears on pulleys, wheels on cars, etc.

This is all fine and dandy in that part of the learning process is understanding that we simplify down a scenario into dots and circles (as seen in the beloved physics joke “consider a spherical cow (or chicken)…”). But what worries me about these drawings popping up in class is that is the sort of information I would have hoped the students would have absorbed by reading the textbook ahead of time.

This conundrum deserves a fresh look at goals and methods. Why do I want students to read the textbook ahead of time? I want them to come to class with a working knowledge of the material. I don’t expect them to be able to crank out problem after problem in class, but I want them to come with familiarity with terminology and ways of thinking that apply to what we’re studying. As I tell my students, my strength is not in regurgitating the textbook. My strength is bringing to them verbal or active explanations about ways of knowing. Classtime is about putting the book knowledge into action.

What have I been doing to spur that kind of in-depth reading? I’ve played around with strategies over the past few years, including having students write one-paragraph summaries of what they’ve read. Last fall I administered reading quizzes that were due before each class period. Student feedback, both mid-semester and end-of-semester, asked to have these kinds of quizzes due all at one time for a given chapter, so I switched to that for the spring semester and have continued to do the same thing (this year on Mastering Physics, instead of Blackboard). And I’ve got about half a page’s worth of explanation in the syllabus about what I mean by “read before class.”

But my sense is that it’s still not working quite right. Students are still coming to class with some very basic questions (such as, “what exactly is mu [the coefficient of friction] again?”) They also have been looking at me (forgive this insertion of a southern idiom) like a calf looking at a new gate when I start different analysis types, like objects on inclined planes. (“Why are we working with a tilted Cartesian plane?”)

So I’m going to gently change up the reading quiz method to (1) have at least one question due before every class and (2) have at least one question of each set be an actual problem to solve, hoping to move this pre-reading into workable knowledge territory. This isn’t revolutionary by any means, but I think is illustrative of a major point of teaching: you’ve got to be flexible. Truly, I’m working with a best-case scenario of students here at Wheaton: they are extremely capable. Freshmen come in with an average 3.7 GPA and the middle 50% of them have ACT scores between 27-32. Of all the students I’ve ever worked with, these should be “getting it,” in the naive sense of that phrase. But if they’re not, it’s time to change up tactics. There’s a lot of research out there about how to get your students to read before class. But I’m starting to feel as though it depends upon a very wide variety of factors that can change from year-to-year, even at the same school. Not to mention the fact that the act of “reading” means very different things to different people.

I speak to my students about the syllabus being a “living document.” Policies and procedures are not set in stone. I do a mid-term anonymous evaluation in which I ask students to comment on what they’d like to be started, stopped, or continued in our course. I usually end up changing up some things after that point. But it’s totally worth changing up things earlier if need be. We’ll see how this experiment goes.

[Image Creative Commons licensed / Flickr user The Bees]

*See The Big Bang Theory

ABCs of FBDs

Heather Whitney — Fri, 16 Sep 2011 18:45:17 +0000

This year marks the fourth I am teaching some form of introductory physics. Some factors have changed (institution, textbooks, student ability level) but I’m finding that some things remain the same. I’m getting a better handle on the common misconceptions my students have.

A big one revealed itself this week regarding free body diagrams (FBDs) and Newton’s third law (or N3, as I abbreviate it.) Randall Knight’s College Physics textbook, which we’re using, spends a whole chapter on just understanding what forces are and practicing drawing FBDs. I appreciate this approach, especially for intro physics for non-majors, because it helps students face their misconceptions about what forces are and helps them understand that the drawing of the scenario often motivates the solution.

This Wednesday in class I broke out for the first time this semester our mini-whiteboards,* passed out markers, and got the students into groups of three. We practiced drawing FBDs straight from drawings and translating FBDs from word problems. Each group switched drawers for each successive problem so that everyone had some practice while the other members of the group advised.

This procedure was really revealing: FBDs AND action-reaction pairs were all over the place. Below is an example of what I’d draw if I were working one of these problems (Rachael and Jon are pushing on a box, which is moving at a constant speed in the direction Rachael is pushing), and what the students typically drew (sans hands actually gripping a box, feet with toes on the floor; they got quite detailed with their drawings!). Note that the vector lengths are not in their proper scale in either drawing (they should be; I was just a bit lazy in drawing this for this post.)

Note that the students have drawn the action-reaction pairs for all the forces, instead of just the ones acting on the box. As they were drawing, questions started popping up, largely along the lines of ”if everything has an action-reaction pair, how does any movement happen at all? Isn’t everything just in a deadlock?”

What to take away from this? First of all, getting students to draw in class and getting a look at their work can be very revealing. If I were to have just drawn the figures for them in class and they copied along, we would not have had this chance to confront the misconception. They might have gone on from this point just doing their drawings “because Dr. Whitney drew them this way” and not understanding the utility of a FBD. They might not have even gotten the drawings right from this point on, which would then affect the work they would do as we approach future topics like torque.

Secondly, I’m not sure I’ve ever seen a textbook that clearly articulates that identifying action-reaction pairs for N3 and drawing FBDs are separate analyses (that sometimes work together) with different purposes. Admittedly, my sample size is small; when I was in college we used Serway. I once taught as an adjunct using Young/Freeman. My first year of college teaching we used Giambattista and I switched to Knight the next year. Knight does go through the practice of drawing two FBDs for two objects and then drawing a connecting line between the action-reaction pairs, an approach I appreciate. But not all problems use two objects with clearly identifiable N3 pairs. Sometimes we’re just interested in one object sitting on an inclined plane. The weight does of course have an action-reaction pair (with the earth), but we don’t draw it in. And so when students are left with something not having an obvious N3 pair they are sometimes conflicted about what to do.

From this situation, takeaways for me are to (1) get the students to be active in class, (2) give yourself opportunities to see their minds working so that you can facilitate corrections, and (3) always be on the lookout for ways of knowing that are obvious to physicists but should be stated clearly for students.

Preview for my next post: I’ve got a strong policy of reading the textbook very deeply and carefully before class begins. Why did my students draw such complicated drawings of FBDs, instead of in the simplified form as directed in the textbook?

*Our intro room has been designed to have whiteboards all around the classroom to facilitate work like this, but because enrollment has grown in my class we’re meeting in a room in a different department.

Summer wrap-up

Heather Whitney — Thu, 25 Aug 2011 15:18:58 +0000

(view from our cabin at Honeyrock)

We’re two days into the Fall 2011 semester, but here’s a wrap-up of how my summer went:

Two days after graduation, we hit the ground running with summer research. I worked with two Wheaton students on two different projects, one on NMR and another, in collaboration with an applied health sciences professor, on ultrasound. We all spent ten weeks together and I believe made some good progress on getting the undergraduate version of my research up and running. My NMR research was a little hampered in that there was a delay in getting our new machine delivered, but it’s slated to be here in September. Through the generosity of a researcher at NIU, we were able to run some rudimentary experiments that confirmed that we’ll need to deal with radiation damping in our experiments. I look forward to tackling that. It plagued me a bit in grad school and I’m ready to figure out how to avoid it in my experiments. We also made some estimates on what sizes of polymers might be present in the polymer gel dosimeters at different doses, something that has not yet been able to be identified by experiment since it is very difficult to extra the polymer from the gels after they have been irradiated. On the ultrasound side of things, we’ve been developing some software for making a certain kind of measurement and spent the summer making phantoms and testing the software. We’ll move on to human studies hopefully soon.
We took all the physics department summer resarch students to see the plasma labs and medical physics department at University of Wisconsin-Madison. They have some fabulous facilities up there and we all enjoyed getting the insider’s view by one of my colleagues, who did his PhD there as wellas some years as a researcher. We also stopped at the world’s largest Culver’s on the way home. Later in the summer, I toured Fermilab for the first time.
I attended four conferences: THATCamp LAC at St. Norbert College, Gordon Research Conference on Magnetic Resonance at the University of New England, the conference for the American Scientific Affiliation at nearby North Central College, and the summer meeting of the American Association of Physics Teachers at Creighton University. It was great to meet some people I know from Twitter and through ProfHacker, as well as reconnect with others I’ve met previously.
I finished up the summer by teaching in my college’s orientation program, Passage, at Honeyrock in Three Lakes, Wisconsin. We faculty had a mighty fierce go-karting session one evening.

The summer flew by! This fall I’m teaching algebra-based intro physics, intro to medical physics, and computer modeling, as well as working on several projects and serving on two committees. Life is busy, but full and fulfilling.

New feature: subscribe to pages, not blog posts

Heather Whitney — Fri, 05 Aug 2011 15:19:35 +0000

An email I received after the AAPT summer meeting reminded me that sometimes it’s useful to be able to be notified of changes to WordPress Pages, not blog posts. To address this, I’ve added an RSS button to the bottom of the Resources page (which has info pertinent to my talk). Scroll to the bottom of that page and you’ll see the RSS feed specific to that page. The larger RSS feed button at the top will still subscribe you to blog posts.

A Scientist Walks into a THATCamp…

Heather Whitney — Mon, 06 Jun 2011 20:28:29 +0000

Last weekend I attended THATCamp Liberal Arts College (LAC) at St. Nobert College in De Pere, Wisconsin. You might immediately wonder, “why is this scientist going to THATCamp?” Here are a couple of reasons why I attended.

1. The chance to meet up with other Profs. Hacker. I’ve been a part of the blog for over a year and had yet to meet any of my fellow bloggers in real life. The opportunity to meet three of them was just too good to pass up.

2. To learn more about how the unconference model might apply to my interests of NMR/MRI and physics education research (PER). If the terms “THATCamp” and “unconference” are new to you, check out this post from THATCamp prime.

The first reason might not seem so strange, but why am I interested in the second? Because, just like general physics textbooks, the professional activities that surround the different physics worlds in which I’m involved are bloated. We have huge conferences which can cause attendees to incur great expense and in which a person can be completely passive and not really engage with a single person. Publishing time frames can stretch on for half a year, even longer sometimes. It can be very difficult to get practical, timely information that helps you do your work.

Formal activities, such as conference attendance and traditional publishing, definitely have their place and value. I, for one, am extremely grateful for the relatively long, very respectful history of publishing in PER. No matter what field you are in, there is likely some helpful pedagogical information out there for you in PER. That community does a great job of carefully vetting studies and curating trustworthy results. In PER and science in general, it takes time for the scientific method and peer review to do its work. But while there is a time and place for formal activities, there is also a great need for swift, flexible communication of more casual information that can help a wide variety of people – and maybe even lead to greater formal innovation.

The ethos of THATCamp fits this need in some way. Put together a bunch of like-minded people who meet up at a low-stakes (and low-cost) situation and ask them to come up with their best ideas. Crowdsource those ideas and let the group weigh in on where, when, and how to discuss them. It’s chaotic, but it can work wonders.

How does this apply to my work? I currently have several questions swirling around in my head, ones that seem applicable to a THATCamp-type activity. How do I start to build a training program for undergraduate NMR research, one that takes into account that they’re physics majors, not chemistry majors, and they understandably need a lot of assistance with getting started? How do I start to build a body of information, practical tips, how to’s, etc., that can be passed on from a student that is with me now to the one that will work with me next summer? How do we, at our very small school, start to be good stewards of an upcoming big equipment install, when at larger ones the associated maintenance tasks would be taken on by full-time staff? What are some things I need to know about running an NMR machine that are likely known very well by folks at other places, especially regarding troubleshooting of the machines? What are best the best practices for scheduling time slots for its use? What kinds of physics demos are out there that I don’t know about? How do I find out about them without having to troll through a ton of literature? Who else out there feels a bit isolated and would like to cultivate a community of like-minded physicists at small schools, so that we can work together on potential grant proposals? How do we actually collaborate on these proposals?

These are just a few of the questions that swirl throughout my head every day. They are part of the work of being a faculty member at an student-focused undergraduate institution in which research is an expectation. I need information that is timely and for which I don’t have to wait for a formal publication (and truth be told, doesn’t really need a formal publication), and I need to learn from others what their questions are because they might apply to me as well.

Is a THATCamp an appropriate place for these discussions? Maybe. I think a successful THATCamp depends upon a number of factors, including a carefully articulated identity so that attendees comes with a shared, distinct purpose. I also think that attendees need to come with an overall positive perspective, so that the sessions don’t slam into a wall of complaint. (And kudos to the THATCamp LAC people, who did a wonderful job staying positive.) Finally, I think a major determining factor of THATCamp success is streams of communication before and after the conference. Twitter especially is a critical tool in getting conversations going and maintaining them. As far as I know, there is not that kind of strong, informal community out there yet in my interests, particularly in PER. I’m lucky to know a few fellow physics teachers on Twitter, but there could be a lot more.

So that’s my THATCamp LAC wrap-up. Many thanks to all the people I met at the unconference and didn’t seem to mind the intrusion of a science person.

Favorite (recently read) books

Heather Whitney — Mon, 18 Apr 2011 14:51:59 +0000

The other day, one of my students asked if I could give her a list of my favorite books that I’ve read recently, whether they are science-based or not. I was happy to do so, and thought I’d share the list on this site as well. Here they are, in no particular order:

The Spirit of Food: 34 Writers on Feasting and Fasting toward God edited by Leslie Leyland Fields. Beautiful essays on the physical and spiritual nature of food. And some good recipes to pick up along the way.

The No. 1 Ladies Detective Agency series by Alexander McCall Smith. Start with Book 1. What a charming series!

Galileo’s Daughter: A Historical Memoir of Science, Faith, and Love by Dava Sobel. Enjoyed getting a different point of view of Galileo as father as well as scientist.

Fidelity: Five Stories by Wendell Berry. Although I didn’t grow up on a farm, my grandparents had one, and somehow Berry draws out that heritage that is buried deep within me.

A Midwife’s Tale: The Life of Martha Ballard, Based on Her Diary, 1785-1812 by Laurel Thatcher Ulrich. A fascinating account of womanhood in the early years of our country.

Among His Personal Effects by J. Craig McDonald (I’m a little biased towards loving this book, because the author was my college honors English professor, whom I admire very much.)

Musicophilia: Tales of Music and the Brain by Oliver Sacks. Sacks can be a bit rambly, but his investigations into how our brain processes music are fascinating.

A Year in Provence by Peter Mayle (as well as his other books on living in Provence). Full of good adventures and good descriptions of food.

[Image Creative Commons licensed / Flickr user Mr. T in DC]

Advice for students giving presentations

Heather Whitney — Mon, 11 Apr 2011 15:03:44 +0000

Last weekend I had the privilege of chairing two physical science sessions at the Associated Colleges of the Chicago Area (ACCA) Student Symposium at Elmhurst College. The undergraduate students in my sessions presented some very fascinating accounts of research projects, and I was impressed by their ingenuity in constructing some fantastic experiments and in recasting some complex theories of physical phenomena into simpler relationships.

Overall, the students did very well, and it was clear that they had done some practice ahead of time. However, there were some little hiccups that reminded me that often we prepare our students for the actual presentation, but not always for its context within a series of presentations. Below are some suggestions I’m hoping to talk about very explicitly with my students when they prepare for talks in the future.

When presenting as part of a series of talks, such as in a symposium, check in with the moderator upon arrival. Let them know you are there.
Sit as close as possible to the presentation area so that it is easy to step up when it is your time to speak.
Try out your presentation system ahead of time. Whether it’s needing to connect a laptop or use a file from a flash drive, there are a number of ways that what you think will work might be foiled. For instance, the assignments were backwards on the presentation system in our session for switching between laptop and installed computer. We also had just one USB slot to work with on the installed computer. This stymied a few students, who had been planning to use both a flash drive and a USB clicker for going through slides.
Carefully design your slides so that they are viewable in both dimmed and bright lighting environments. You never know which you will get.
If more than one person is speaking in your presentation, have a clear plan of who speaks when. You might even consider having each speaker step forward during their part.
Cast your research in a positive light. One presenter summed up her investigation by saying, “here are my results, but I don’t think they are meaningful at all.” I think what she was trying to get across was that her model was very, very basic, but that’s valuable in helping us to understand the phenomenon (and a great first step in the scientific method.) If you speak negatively about your research, others will think that way as well.

For all the focus that we put on helping students present well, more must be done to help them be aware of the context of their presentations. What would you add to this list?

[Image Creative Commons licensed / Flickr user MattHurst]

Mid-semester check in

Heather Whitney — Thu, 31 Mar 2011 16:59:49 +0000

One of my favorite professors in college warned us after each spring break that the time between then and the end of the semester is the fastest of the entire school year. I believed him then, and I believe him now. It’s amazing how fast time can pass.

This semester has been busy but satisfying. At Wheaton, we have both full semester classes and half-semester ones, which we call quads. Quad A I taught our physics of music course, fulfilling a long-term dream of mine. It was a fun class, full of both musically-inclined students from our Conservatory and others there for the general education credit. One of my current projects is to develop a better curriculum for this course, since the majority of what is out there isn’t physics education research-minded and is written from a very electronics-heavy view of music. My sense is that the course should focus firstly on the role of physics in the production of sound – recording methods should be a later emphasis (if at all!) We did some fun activities, such as measuring the speed of sound and using clicker interactive lecture demonstrations. I’m starting to revise these for sharing with others, and the first few are up at my resources page.

The semester so far has not been without a bit of fun; the picture above is from a drive I made up the California coast on scenic Route 1. It was my first trip to the state and I had a lovely time.