Secret message to my first year experience students

Sometimes it helps to read more than the title of an article before answering the homework question that asks what the article is about.

Share my pain

The setting: An exam in a non-science majors general science sort of course. The question: Natural uranium is 99.3% U-238 and 0.7% U-235. What is enriched uranium and what is is used for?


Here is a sampling of the most painful responses:

• Enriched uranium is uranium made to be more polar
  
• Enriched uranium is present in U-238 and used before
  
• Enriched uranium is used for buildings
  
• Enriched uranium is processed and used for cleaning
  

On Books and Shoes

I met my honor's class for the last time today and gave them each a science-related general interest book for summer reading. Among the books I handed out: Bright Earth by Philip Ball (to the Art major), Critical Mass by the same author (to the student interested in nuclear issues and politics), Cities in the Wilderness by Bruce Babbitt (to the student interested in sustainability), and Oxygen (the play) by Carl Djerassi and Roald Hoffmann (to the theater major).

I do this occasionally for non-majors in small (<10 students) classes when I've enjoyed their enthusiasm (and I think they will read and enjoy them). I also give books as graduation presents to our majors. Total cost for the non-major class: $105.73. (Paperbacks, nothing fancy.) I figure I bought these and these for myself recently for no defensible reason^*, so what is $106 to support lifelong learning in science?

 

 

^*Other than my obsession with Reebok Freestyle hitops which I've been wearing for 25 years.

The cooling scare of the 70's

Today, a student in one of my classes said she had heard that in the 70's everyone thought the world was cooling. She wondered if it was true. Of course, there were a few headlines about this idea in the 70's, and this is a commonly cited among doubters of climate change. Fortuitously, Real Climate had a post about this recently, which I was able to send around after class:

Here's a quote:

Remote sensing, integrated global data collection and modeling were all in their infancy. But our analysis nevertheless showed clear trends in the focus and conclusions the researchers were making. Between 1965 and 1979 we found (see table 1 for details):

* 7 articles predicting cooling
* 44 predicting warming
* 20 that were neutral

In other words, during the 1970s, when some would have you believe scientists were predicting a coming ice age, they were doing no such thing.

Missed Exams

When I first started teaching, I was stunned to find out that students actually missed tests! They sometimes just don't show up! Who knew?

I quickly grew tired of feeling like (a) a failed lie detector (b) a pushover or (c) a resentful bitch instructor, so I searched for a better way.

In my lower level classes, I adopted the "retake" policy of one of my former colleagues: everyone gets to take one (modified) test over for any reason. That seems simple enough, but the policy does get more complicated: If you didn't take the test the first time, you must score at least X to have your test counted. If you did take the test the first time and you score higher, you get the higher score. Score lower, but within Y points of the first attempt, keep your higher score. Score more than Y points lower and your score is determined by this ultra-complicated formula: (2*HI+LO)/3.

This provides a negative incentives for skipping just because you can, as missing tests is not, in my experience, a good omen for success. There is a small risk of retaking so if you are not prepared, you won't waste my time, or yours. The, um, "ultra-complicated" formula seems to be a deterrent as well, simply because some students aren't sure what it means.

So does it work?

Yes! I love this system. I also love that the student who blows the first test (Whoa! college.... Science...) but gets organized and buckles down can re-take that first test (in a similar incarnation). My current record point increase is 54 on a 100 point test.

I don't do this in my upper level classes. Why? Because I've never really had much of a problem there. Then this happened. The short version: one student, called Jill here, missed an exam and had a "suspicious" excuse. Whatever. This is rare enough in this class, I let it go. Everyone in my upper level classes gets the benefit of the doubt the first time. Then Jill asked another student what was on the test. I believe she skipped the test to gain more study time, and the cheating attempt was a crime of opportunity, but either way, I was not happy.

So now, the "Jill Rule" joins all the other specific rules added to my syllabus because of the actions of one student. There is the "Bob Rule", the "Alexis rule" and even the "Crazy Paranoid Student Rule". What is the "Jill Rule"? An XX% penalty on exam retakes for unexcused reasons.

Guess who missed the first test this semester? I guess she didn't read the syllabus.

Today I Love Teaching

Astrodyke linked to a great article about the total lunar eclipse. Among other things, it explains why the moon looks red during the eclipse.

I could not help myself, so I sent an e-mail to students in my last semester's general education science course. In this class we talked about many many different things - but one of them was sky color during sunsets.

Hi former [cool physchembio gened] students!

This article explains why the moon looks red in a total lunar eclipse (See the section "Red Light in the Dark"):

http://www.skyandtelescope.com/observing/home/15357796.html

(And, if you are getting this note in real time - the eclipse looks pretty cool right now!)

- Prof. Twice

And I received back:

I was talking to [another student] earlier and said "why the heck is it red if the Earth is between the moon and the sun blocking the light?" Lol, now I know the answer. Thank you!

Hope the semester is going well,

-A. Student

In another nice episode of perfect timing in teaching, our seminar speaker (a guest I invited, but from a totally different sub-field) spoke about a phenomenon I covered only 6 hours earlier in class. Gotta love it when that happens.

On the not-so-great side, due to the total eclipse of the moon and coming of age in the eighties, I now have the song Total Eclipse of the Heart stuck in my head. And now perhaps you do too. Sorry.

Still lovin' the honors class

Friday:

I had a number of basic phys/chem/bio topics I wanted to review in the honors class. One was scientific notation. I did not do an assessment on this, so I just asked "Do you remember how to use scientific notation for large and small numbers?" The entire class (of 8) nodded. "Okay, should we review a few just for good measure?" They shrugged in a way that said to me "sure, knock yourself out" but admitted it wouldn't hurt. So I put up one "large" and one "small" number, reminded them to use the correct button on the calculator (not the 10^x button). Everyone seemed satisfied and agreed we could go on. Total time spent: 2.5 minutes.

Good Problems

My honors class (non-science majors) is up to eight students. Last week, it had seven and the Honors Program secretary called me and offered to cancel it if I didn't want to teach a class that small. If I didn't mind, she said the director wanted to let it run. So do I mind? Uh...No-o.

The first day, I tried to find out a little about what the students already know about physchembio. Good thing too - several had taken an AP class in high school. A few more had an honors class in high school. One had taken a semester of college physchembio. And highest math level? Two with trig, a bunch with pre-calc, and one with calculus. Nice.

To find out how much they remembered, I gave a quick assessment: "Define/describe these five basic terms/concepts from physchembio." They worked individually for awhile, then I broke the class into two groups and had each group repeat the assessment on a new form. It works well - they talked about science and reviewed what they already know - I find out what that is.

And what do they want to learn about? Here is a sampling: Is ethanol going to save the world? Will a killer asteroid hit the earth? Stay tuned.

A new challenge in storytelling

I'm about to begin my spring term of teaching, and I find myself wondering:

Which stories do I tell?

How should I tell them?

My science class for non-majors is an "issues" course. That is, we look at current issues in science of interest to the general community. Energy, climate change, that sort of thing. Back in the day, I used to present both sides of the global warming debate. I thought I had to, you know, to be fair. I don't know why - maybe to overcompensate for my liberal nature. As I became increasingly uncomfortable with this, I began to minimize the debate itself, and just present mechanism, facts and numbers. I addressed the debate, but only briefly.

In 2005, after a break of a few years, I taught the course again. Just beforehand, I went to a seminar where I had the opportunity to discuss the issue of what to present in class with real climate scientists. The other instructors (non-climate scientists like me) and I wanted to know what to do about the other side of the debate. We all felt some discomfort not presenting both sides. The climate scientists felt no such discomfort. "Present IPCC," they said, "this is the consensus of the scientific community." A fine point, I thought.

I presented the IPCC conclusions. I talked about how climate modeling was done. I showed Hanson's famous graph and explained how it was routinely misrepresented. This all went well. Half way though the term (and after the climate change section), the students in my class asked where I fell politically. I told them I try not to discuss my own politics. They said, "But we want to know!"

There are two schools of thought on this question: full disclosure and don't ask, don't tell. Having opted for the second, I now found myself facing a room full of students asking for full disclosure instead. Astonishingly, to me at least, they went on to say, "We really don't know!" How could they not know? Anyway, there was really no conflict here. The students asked me a fair question. They knew me well enough to believe me when I said the following: "Me? OK. I'm a raving liberal. Does that mean you have to agree with me? No. Does that mean your grade on issues papers depends on agreeing with me? No. I care that it is well written. I care that you have reasons for your opinions and that you can articulate them."

So, what have I learned? A reasoned approach to the evidence does not necessarily get you branded as a raving liberal.

I'm teaching this class again this term. I was planning on taking the same approach. This is all well and good. However, I find myself wondering if my story needs to change. Why? Well, there is a faculty member on my campus who is a global warming skeptic. He teaches this topic. A lot. His contention that climate change is not caused by humans is appealing to the students. And why wouldn't it be? It means they don't need to think about changing their lifestyles. It is hard to counter this.

I'm hoping the way I tell the story of climate change is up to the challenge.

scientiae-carnival

I concede Wikipedia is not without its problems

I love Wikipedia. I think it has its uses in education, but the challenge, of course, is for us to help students learn to use it appropriately. I wish I could somehow make this happen before they use it inappropriately. On the other hand, inappropriate use sometimes provides me with an opening. Here is an exchange with one of my general education students. The course is theme based and could be something like, let's say, science and art.

To: twice@slac.edu

From: studenta@slac.edu

Hi Dr. Twice: I am curious about a question on the online quiz. The question is "approximately when did synthetic pigments come on the scene?" I answered 200-500 years ago and it was wrong, so I took the test again. The question appeared so I answered 500-1000 years ago even though I was certain it as 200-500 years ago and again it was wrong! I do not understand since everything I have read points to the
1700's and Prussian blue being the first synthetic pigment.

What am I missing?

[Student]


----

To: studenta@slac.edu

From: twice@slac.edu

Hi [Student],

On page 187 in Colour: Why the World isn't Grey, Rissotti explains that the first synthetic pigments were used in the second millennium B.C. (White Lead and Blue Frit, for example). I realize that Wikipedia in one place says Prussian Blue was first, and in another place that it was the first _modern_ synthetic pigment. However, the assigned reading in the Colour course textbook, makes the distinction between natural pigments (minerals), and synthetic ones (those that must be manufactured in some way), without somehow limiting the idea to the modern era.

Please note that Wikipedia is a site with user generated content and, while incredibly helpful, is not necessarily authoritative. This section, and in particular this claim, on the Wikipedia site is not fully referenced, which makes it more questionable. (It is best to confirm these details with other sources.) While the 1700's and on were extremely important in the development and use of synthetic pigments, synthetic pigments were used in antiquity.

-Dr. Twice

I'm in the middle of an ongoing (seven months!) e-mail discussion with my husband, my husband's first cousin once removed, his second cousin (the son of the f.c.o.r) and his sister's husband (my brother-in-law-in-law) on the merits of Wikipedia. The f.c.o.r. thinks it is bad, bad, bad. He has a humanities background, the others, who are more in favor of Wikipedia, have technical backgrounds. I've read several newspaper and magazine articles in the midst of this discussion that speak to this divide. Scientists, in general, are more likely to feel positively about Wikipedia. Reasons suggested include a greater likelihood of participation in the creation of wiki content among scientists, a higher comfort level in the scientific community with on-line collaboration and the earlier adoption of this format by scientists. All of these lead to perhaps more developed and vetted articles in the sciences, leading to more use/trust/participation, leading to more developed and vetted articles, and so on.

I sent the e-mail exchange to f.c.o.r. His response?

"So there!"

In my defense, I never said there weren't any problems. And the pigment entry has been updated now, one of the strengths of a wiki.

What I Like About My Online Class

I teach an on-line general education science course for non-science majors. The course is theme-based, and physchembio 101 principles are integrated into the course as needed to explain various phenomena in the theme.

It is considered a "hybrid" course. I have on-line lectures, discussion board post requirement and quizzes. There are also traditional homework assignments and short writing assignments. The hybrid part is this: every other week we meet on campus for lab. The lab meetings are used for laboratory activities, exams, and regular classroom stuff - help with homework, review of difficult concepts, and some introduction of material that is just flat out easier to do in person than on-line.

I'm very happy with this course, and one of the reasons it succeeds is the on campus meetings. These meetings give the class a sense of camaraderie and allow me to establish a class personality. They also allow us to do cool experiments, and ensure the students have an opportunity to ask questions in person, and give me a place to do organizational stuff beyond sending long explanatory e-mails. I also have the ability to give closed book exams. At our small college, we do not have a testing center or any similar setup, so there would be the possibility of a roommate doing an on-line exam - hence my preference for the in-class kind. In class, I can also help people learn how to use their scientific calculator, do cool in-class demos, and sit down with students after the experiments are over and work through stuff.

I recently added weekly on-line quizzes on the reading. I used the question pool feature of Blackboard to create a pool of questions, and the students may take the quiz as many times as they wish. Each time, they get a randomly selected set of questions, and I create enough questions that most quiz attempts will contain unique different questions, though there will be occasional repeats. As far as I can tell, students use this appropriately. The take the quiz once, study some, and come back an try again after some time is passed. When they come back, their score is usually much higher. When they are close to a perfect score, there will be multiple attempts in a short period of time, separated by 10 to 30 minutes. I'm anxious to see if this helps their exam scores any, and what they think of the whole thing.

Now, if I just had fewer classes to teach, I could offer this course more often.

Meetings

Nothing like spending the day in a series of college wide meetings! Today was a day chock full of:

1. breaking up into small groups
   
2. discussing things no one will agree on
   
3. reporting back to larger groups
   
4. repeating steps 1-3 n times
   

All the while with the growing realization that my UTI was not, in fact, cured by the week of antibiotics.

But actually, I am a glass half-full type of gal, so let me say there were three positive things about today:

1. The bathroom was right next to the afternoon meeting room and had an abundance of stalls.
   
2. I succeeding in arranging to have the committee empowered with forming other committees assign a mathematician to join me on the core curriculum revision committee
   
3. I'm now in possession of Cipro
   

Responsibility

So, it looks as though the committee charged with revising college core requirements has been appointed rather than elected.

Number of people on the committee: about 13

Number of science and math people: 1

When Geeks Marry Hippies II

Last summer, we visited my father-in-law and assorted members of Dr. H's family. This included his sister (SIL), a self-described hippie, her husband (BIL), a geek with hippieish tendencies acquired by marriage, and their two children. Dr. H. is a full-time geek and part-time hippie. Dalton and Curie were both super fussy before bedtime. SIL and her husband inquired as to what the problem might be, hoping to help.

"It's teething" I announce sadly.

"We have homeopathic teething tablets!" SIL says cheerfully.

Uh Oh. Dr. H. looks at me, presumably willing me not to speak.

Shockingly, I can't help myself.

"We don't do homeopathy. As a physchembio-ist, I can't possibly." I say.

"What do you mean?" SIL asks.

"Look, I really don't want to get into this. I understand that some have proposed theories that get around the Avogadro's Number problem, but I don't find any of them credible." I say. "I gave them acetaminophen."

This statement turns out to be problematic, because I've assumed SIL and BIL know about the Avogadro's Number problem, a fundamental flaw of Homeopathy. Instead of discussing the Avogadro problem, I have jumped ahead and begun criticizing the alternative theories developed by homeopaths to get around Avogadro. At this point, I am assuming that SIL and BIL have heard of these also. It turns out that SIL and BIL do not know about the Avogadro's Number problem, just as most other people have not. In fact, most people have not heard of the assumptions that underlie homeopathy in the first place. SIL and BIL are aware of these assumptions, just not the Avogadro problem.

Unfortunately, I do not yet realize this, so I begin to explain why one of the Avogadro problem work-arounds doesn't hold water. One mention of vibrations of water molecules and I've convinced them I know nothing about the topic at hand.

"That's not what homeopathy is." SIL says, patiently.

At this point a few sentences of clarification are exchanged. However, things are still messy because I jumped into the argument in the wrong place, and everyone is talking at once. Fortunately, BIL is quite good at negotiating such conversations and getting everyone onto the same point. "As I understand it" says BIL, "the idea is that you choose some ingredient that may have negative effects similar to those you are experiencing. Next, you dilute it heavily. At the high dilution, it no longer has the harmful effects, but your body still recognizes its presence, and reacts to it."

"I understand that, but what I'm saying is that most remedies are diluted so heavily there are no molecules/ions of the original substance left. Or more correctly, only a very, very small chance your particular dilution has one."

SIL says, "I agree that would be a problem."

I breathe a sigh of relief that we agree on this last point. We leave it more or less at this point. SIL believes there must be more to this story, and thinks, perhaps I am getting something mixed up.

Several weeks later, I politely send them the article by Bob Park linked above.

They use other remedies for teething now.

Last fall, my Physchembio for Poets class and I went through the calculations for a 30X homeopathic dilution. They looked at the numbers. I said nothing. They looked at each other. I looked at them. One of them finally said "So, it's just water?" This is exactly why I like teaching general education classes.


---
By way of explanation: I had to wait for 15 minutes to pick up a prescription yesterday and was trapped near the homeopathy aisle, thus provoking this rant.