Sunday, June 27, 2010

Leaky Student Memories

Dean Dad picked up on my article of a few days ago and wrote a great followup to my followup that linked it with an e-mail request for help and an anecdote of his own. If you didn't see it, go read it now (as well as the IHE version) along with the comments. There are good ones on both sites, several of which deserve additional remarks.

Since I already posted some comments as CCPhysicist on the original DD blog, I figured I should shift over here before getting carried away in his comments section.

First, I'll include the same back link to my early writings on the "concept of prerequisites". Those came in my first wave of academic postings three years ago when I started the blog. I find that early article interesting to read because some of my views have evolved since then as I have studied it further (sadly, I think some of that is unbloggable). I should also link to the article where my readers and I came up with the idea of using basics rather than prerequisites when talking to students. However, the one area that gets more and more of my attention is the role of K-12 testing, as mentioned in the comments on DD's blog. Those, first mentioned here, have strengthened every time I talk to students about their pre-college experiences and compare the current generation of students to ones who didn't grow up in that testing culture.

But enough of that. Let's get to the new stuff.


Dean Dad told this story:

I recall a student I tried to advise at Proprietary U. He was several semesters into his program, and he was choosing classes for the following semester. I mentioned that course x was next in the sequence, and required for his program; he objected that it covered a software package he didn’t know. I responded that the software package was covered in the class he was currently finishing. His response, which haunts me to this day: “but that was over a month ago!” His tone suggested that I was being completely outlandish; he was just mannerly enough not to end with “duh!”

I found this fascinating because the student was still in the class that taught the prerequisite material! Presumably he still had a final exam to take, but maybe that is presuming too much about how they do things at Proprietary U. More likely it was a module on one programming tool that was tested with projects and the like before moving on to the next tool.

But I take some exception to DD's conclusion:
Some of that is just a cost of doing business. Memory can play weird tricks. .... But it’s also true that thoughtful course sequencing -- which presupposes both thoughtful curricular design and steady academic advisement -- can provide reinforcement of key skills.

precisely because the student was still in the class teaching that new skill. You see, not only didn't the student know the new programming language or tool, the student didn't know it was going to be used in the next class in what I assume (from the story) was a clearly defined sequence for a "workforce" type program like ones that my CC has. I see this as an oversight by the instructor, although it could very well be the fault of the university if the instructor was a part-time adjunct who was not even aware of the curriculum. (Why else would Prof DD be advising a computer science student, given what DD says about his academic background, rather than the instructor.)

What would I recommend in this case to a colleague? First, that the subject of this programming language should be introduced by identifying when (meaning both the future classes and semesters, but also the career types) it would be used. I recommend something similar to my calculus colleagues when they introduce limits to students who "just" want to learn derivatives, and do something similar at certain key points in my physics course. Second, maybe the exam on that language should include questions about where it will be used. Hey, that is an idea for my physics class! Third, don't just say it the first day. Say it at least every week, much as I use the "this week in lab" or "next week in lab" observation to link what we are doing (or did several weeks ago) to our lab class.


Several comments made explicit reference to the known fact that it is always easier to relearn something than learn it the first time. I know this quite well, but that is not the problem I am talking about here. (Hey, I too forgot lots of things along the way, so I frequently use the prompting/review example technique Cherish wrote about in the comments. Ditto for what Ivory and Lisa wrote, as well as HS lab partner of Dean Dad. I'll come back to a few of those later, since I think they are worth emphasizing just for my own future reference.) The problem I am talking about is when students have allegedly learned something several times and still don't have a grasp of it. My favorite example (listed in one of my previous articles linked up above) is the logarithm. Widely used as an essential computation tool in pre-calculator days, it remains an essential tool because exponential behavior (and, hence, exponential functions) are so common in nature. But students don't seem to really get it until the fourth time around.

We first teach it in college algebra, and I have seen the test questions used as well typical final exam questions so I know the skill level in that class. We teach it again in a pre-calculus class, where (based on the principle described above) they should just pick it back up and move on to new applications. Yet I have seen students struggling well past the end of an exam period on a pre-calculus exam that mostly contained questions just like the college algebra class. That part of the class was effectively starting from scratch. However, the ones who survive that class and log integrals in calculus seem to have learned it when I give a pop quiz on them before starting RC circuits. The fraction that survive that sequence, however, is not large. I don't think it is an exaggeration to say that the lack of even partial retention plays a key role in our retention problems in math.


Gordon McAlister mentions Problem Based Learning in a comment on the IHE version of DD's blog. Although I have an aversion to Three Letter Acronym solutions to all that ails us, I tend to note that all of physics and math is problem based. The trick is what problems you choose, and what problems you put on tests. My speculation that the student in DD's anecdote was in a class built around modules comes from my experience teaching physics. IME, the worst retention results from a class where the material is tightly compartmentalized. You know, where a student taking Test 4 asks "is this like what we did on Test 2?" Every test should be part "Final Exam" in the sense of sampling key older ideas. Some of the best math profs (in the sense that I love having their students in my physics class) do this on a regular basis, and I do it also.


Ivory posted a link to this critique of the mini-PhD approach to the construction of a syllabus. Yes, this is part of the problem, and it is fascinating to see a familiar problem from physics addressed in the context of a history course. It is long, but all of it (along with the comments) is worth reading. Now we don't have the political baggage they do when deciding whether the Doppler Effect is worth our time (or an exam question) compared to some other worthy subject, but it is the same problem. Clutter obscures the essential.

For me, this is a work in progress, but I will state my criteria: will someone else expect them to know this topic, or is it one where they will be expected to look up the equation that applies to a particular problem and plug in the values? Is it a skill or is it a factoid? Will their BASIC skills get better if I go a bit deeper and challenge them in a familiar area or if I take up this new topic at a very shallow level? I think the answer is that we have to deal with the reduction from 15 weeks of classes (plus exams) to 14 weeks by dropping some things that used to be thought essential. However, I am always quite up front in telling my students that I am not skipping it because no one needs to know it.


Ivory also pointed to an abstract that describes one of those Increasingly Common Five Letter Acronyms (that also needs a few lower case letters) for a teaching technique. It looks to me like this was used in a course that was originally modular (if this is Tuesday, it must be Botulism). This is something that is a lot easier to do in a course like physics, and is almost identical to what a math colleague does on his calculus exams. What I find interesting is the idea of making it explicit to the students that you are doing this: that is, that you value retention of a specific subset of the earlier material. Not by talking about it, but by testing on it.

Definitely something to think about in a survey course where this is rarely done.

But you know something? The humanities courses where I really retained the material (and that make visiting museums a joy) were ones where there was a unifying theme in the interpretation of disparate items. That made you look for patterns as new things showed up, and LOOKING is the first step to real learning. You don't learn if it just washes over you like a rogue wave.

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Friday, June 25, 2010

Memo to Apple: Humans conduct electricity

Perhaps you saw the news stories reporting many complaints about signal loss on the new Apple iPhone 4? (Here is one from yesterday.)

As I guessed, the problem is not with the antenna itself, but the fact that there are two antennas on the phone, separated by a small distance on the case. (See this news story, among others, on what the user must not do and how to fix it.)

The problem is that humans conduct electricity. No problem if there is only one antenna, since that just makes you part of the antenna if you touch it. The problem arises when the user short circuits the gap between the two antennas by touching both sides at the same time. (That means a quick fix would be a bit of electrical tape around that corner until you get the more expensive, but better looking, plastic or rubber case mentioned in the articles.) And since MSNBC does not have a physicist in the news room ... I'll add that connecting the cell and network antennas certainly could explain the problem.

It changes the tuning of both antennas, which is bad enough, but it also means that one poor antenna is feeding two separate receiver circuits rather than each one getting its own signal. It would also short the transmitted signal from one side into the input for the other side, reducing the energy that goes out of the antenna to the cell tower. I have no clue at all what those circuits look like, but a decent impedance match could kill the outgoing signal needed to keep the "line" to the cell tower open.

I don't have one or I would do the simple experiment of shorting the gap with a potentiometer to watch what happens as the gap resistance varies.

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Thursday, June 24, 2010

Job advice from the Academic Jungle

A great new job-related series, this one oriented toward faculty at research-intensive institutions, has started up at IHE. Here is the link to the Academic Jungle index at IHE and to the first article, about the importance of service in the R1 world.

The same article appears in the home blog of the author, GMP. (BTW, "geek mommy prof" is a great nom-de-blog.) It makes the important point that you can't afford to zero out any part of the research/teaching/service triangle. It is sort of a counter-point to the emphasis I put on outside letters in Part 4 of my jobs series, which focused on R1 faculty jobs from the viewpoint of an outside observer.

(I was going to post some of the following additional comments on that blog, but for some reason Firefox does not play well with that particular comment form - so I'll put them here.) One of the comments over there had to do with teaching-intensive jobs. From my viewpoint, it is more than just a matter of flipping research and teaching. As I elaborated in Part 5, we expect a formal teaching portfolio, or its equivalent. Just as you might not know about outside letters until last in the tenure process at an R1, you might not know anything about teaching portfolio if you come out of a research university - which is the case for just about everyone looking for a teaching job.

I'll add that there might be more jobs out there than "Alyssa" knows about, because many teaching jobs are simply not advertised in the same place as research jobs.

I'm going to try again to comment on GMP's sited, but one reason I didn't comment on the IHE version of the article is that I don't like to dump a bunch of self-serving links on their site. But I have no problem doing that here. All of my articles related to jobs (some clearly about physics, but others not at all) can be found in this link summary. In addition to the two mentioned above, I think this one (linking to an IHE career advice column by a female mechanical engineer) is really good for R1 jobs because that article makes many strong points, including one about presenting your case so the inevitable holes are less visible. On the teaching side, this one riffs off of a great article by Dr. Crazy (showing that teaching Physics and English can have something in common) and makes the point about keeping useful records.

Good record keeping, meaning a good process, is essential if you want to document all of the service you have done. No one can do that for you. I use a small calendar whose sole purpose is to document "odd ball" stuff that has to go in my annual evaluation -- and I already have tenure.

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Tuesday, June 22, 2010

Passing one class, failing the next

Dean Dad always has great, thought-provoking blog posts, but today's blog rates a double comment.

First, it really shows the importance of having academic leadership (Dean, Provost) at a CC come out of the ranks of teaching faculty at a CC or comparable institution. (The key issues are different at a research intensive university, but the same principle applies there precisely because the key issues are different.) If Dean Dad the Professor had not had dealt with the question of a perceived conflict between passing rates in a given course and weak students who pass that course, Dean Dad the Dean might not have identified the middle ground he so succinctly describes in his blog.

Second, it identifies what I think is a key issue at any college: getting across the idea that prerequisites have real significance. As you can tell if you follow that link, I've written a lot on the subject. A couple years ago we (meaning my blog readers and I) came to conclusion that COLLEGE-LEVEL BASICS is a better term to use when describing pre-req skills. I have started using it, and have found it a helpful way to get the idea across to the upper level students taking calc-based physics, students who don't think of calculus as a basic skill.

I already posted some comments on the blog article itself under my nom-de-comment of CCPhysicist. My main observation is that the best way to define appropriately high standards for a course is by making it your objective that they leave one course prepared to pass the NEXT one.

IMHO, this is partly a matter of setting high standards from the first day of class and partly a matter of conveying (that is, getting them to absorb into their core beliefs) the radical idea that specific parts of the new and challenging material in my course are actually basic skills. Indeed, I think this second part is more important than the first.


One of the things we (meaning me and my colleagues who teach calculus and trig) talk about regularly is the fact that we all know that certain students knew skill "X" when they passed the previous class - including my own - and forget it within a month. We have to do our best to ensure that we each know that such regular occurrences are not the fault of the instructor, since we can't evaluate what happens a month later, and yet work on ways to reduce how often those situations occur. When I have control, like when students from my own Physics 1 class don't remember to draw a free-body diagram in Physics 2, I make it clear that the failure is completely unacceptable. That if they keep up that practice, they will be laughed at as "community college losers" when they get to engineering school.

(Now, I happen to know - from my graduates - that it is far more common that the university students are the ones who show up with heads empty of knowledge that they paid thousands of dollars to allegedly learn, but that is only because the ones who come back and visit didn't screw up less than a month after taking Physics 1. They learned it the first time. I'm working on getting some of them to talk to my class early in the semester. Students listen to other students more than they listen to us.)

It is not an easy battle. It has to be fought anew every semester. I have learned to make it a habit to mention where some skill will be used in a course next year. I have made it my mission to learn where those places are, by visiting my former students at nearby Wannabe Flagship. I share what I learn with my math colleagues. (What calculus did you use last semester?) Now that summer is here, I plan to head over there in my spare time. The people who teach physics at Wannabe Flagship are much closer than I am, but I doubt if they ever see their students again. They are rewarded for that. Well, neither am I (there are no performance bonuses in our pay system), but I get my reward every time I see the success of students who started out at our CC, particularly the ones who started out a year or more behind the kids at Wannabe Flagship, sometimes in developmental classes.

So, if someone at a university is reading this, visit a different building once in a while and talk about teaching rather than research or university politics. Find out what your students didn't retain, and share what theirs didn't retain. It can't be about blame. I've seen cases where you can document that a student did it perfectly on a final exam one week and could do nothing on the same problem a month later. Heck, I've done it. But only once. One thing I tell my students is to pay attention when they see something a second time. If you don't remember it, make sure you learn it permanently the second time. Anything that gets used in two classes is likely to be used in all of the rest.

To conclude, I want to draw on an example from the comments on Dean Dad's blog. Anonymous wrote at 10:30 AM:

the blame falls to the students for their own inability to learn the course material. They had me, a book, and any previous experience to fall back on (including Comp I and possibly II). Some students do not want to rise to any level that requires work.

The last statement is true, but that might not be the problem. Talk to the person who taught Comp I to a particular student. (At our CC, this is easy to look up but YMMV.) Or ask other students what they did in a particular Comp I class. It could be that the reason they can't "craft a thesis statement and defend it with evidence" is that this was not part of their class. Or it could be that they had learned in HS that each class will teach that skill all over again if it is needed, so there is no reason to learn it. That other teacher might not be able to solve the problem either, but together the two of you might effect a change for the better by the time they take a third class. At some point they need to learn we teach certain things for a good reason.

Or you might learn that the Comp 1 prof used oral presentations in class as a substitute for written work. Ah, the stories students tell other students when they think professors are invisible and deaf ...

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Monday, June 21, 2010

Summer Classes

I've been busy commenting on my fave blogs for the last few months rather than post here, but it is time to correct that oversight.

There was a great question, about teaching summer classes, posted Saturday in the unbalanced reaction blog:

Some of my colleagues complained nearly nonstop through the first summer term. I wonder, is summer teaching REALLY that bad?

No, but it is different. To elaborate on my comments on that blog, I'll start by saying that I just got done teaching the first half of summer here at good old Ishkabibble Community College, and it went well. I didn't quite match the overall success rate of some past summers, because more than 15% withdrew, but everyone who took the final exam got a passing grade in Gen-Ed Science. My success rate in summer is higher than it has been when I taught the class in a regular semester, and higher than the norm for this particular class. Which is not to say that it is actually easier in the summer, just that teaching can be more effective in a short semester. And a few even learned something.

The key?

This wasn't my first summer rodeo, so I started the semester off with a WARNING, some lecture material, a bit of active learning, some demonstrations, and a homework assignment. I gave them two days to do the homework, not because I am a softy, but because students could still add on the second day. I wanted to be able to treat them fairly without having to keep track of exceptions.

The warning is crucial. I share it with new faculty at this CC, just as it was shared with me, although the first time I taught in summer I didn't have enough experience to make the warning as effective as it is now.

I don't pull any punches, but I also don't lecture. Once everyone is settled in and has turned in the information sheets that tell me what I have to work with, I outline the high points of the schedule, and get down to business. I put the course calendar up on the projector and ask a simple question: Who has taken a class in the summer before? (Oh oh, only a few hands went up. If none go up, you have to make the sale on your own.) I ask the rhetorical question "Summer classes go pretty fast, don't they?". Or maybe I snark it with a touch of irony, saying something about how slow and easy they are. Either way, I get a dialog going with the experienced students, and let them warn the others.

That done, I point out that every two class days is like a regular week. Every week is like two and a half regular weeks. If we read two chapters a week in a regular semester, we read five of them in the summer. If we had an exam every 4 weeks or so in a regular semester, we have one every 1 1/2 weeks in the summer. If you normally do about 3 or 4 (rather than the expected 6) hours of homework a week for a regular class, you need to do 8 to 10 (and maybe 12) hours in a summer semester.

It's like drinking from a fire hose.

So what, you ask, makes it easier? The intensity. The final exam is only about a month after the first exam, and only a few weeks after the midterm. Less time to forget. If you review the stuff you missed when you get each exam back, you are halfway to doing really well on the final exam. For most classes, students do less well on a comprehensive final than on the hour exams. In summer, most do better than their exam average would predict, and some do a LOT better.

There weren't as many examples this summer as in the past, but I had one student fight the good fight and go from a low C - high D to a solid B after the final exam. Best of all, none went down.

There are other things I do differently. Like Unbalanced, my summer class is small. I take the time to give them a full grade estimate (exam plus homework) after the first exam rather than wait for the midterm. I point out how the homework partly makes up for low exam scores and remind them that the final exam is just 4 weeks away so they should review right now to be sure they can get those same questions right if they show up on the final. There is an element of coaching involved to keep them motivated in a class as challenging as mine is.

A few closing thoughts.

Some colleagues complained. Yep. Some of mine do, too. (I try to stay away from the ones who always complain. Bad vibes are infectious.) SOME. The others make it work. Talk to the happy ones more than the Complainers, although it never hurts to ask the Complainers what, specifically, the Snowflakes were up to. Your students are different from mine. Mine have jobs and kids, and one texts so much that she had 3 traffic accidents during the semester, but they are generally VERY motivated.

Your class is "just" over 2 hours long? Now I have no doubt that YOU are ready to handle it, but don't assume that they are. (Ours are only 80 minutes, about the length of a normal Tues-Thurs class.) I'd treat it like two classes. Or five or six, since I never stick with any single style for more than 20 or so minutes. Ask yourself, how long before you zone out in a faculty meeting? That would be about the time that you add NaOH to Al foil, trap the H2 in a balloon, and see what happens when you put the balloon near a candle. Then have them work out the reaction at their desks while you circulate to coach them when they get stuck.

Also, even if the class looks like it is long enough to have lots of spare time, you don't have any time to waste. Add them up to be sure, but you probably don't have any more (and might have fewer) minutes in the summer than in a regular semester. You also have to figure out how to handle exams so you don't blow off any of those valuable minutes. Students like to walk in and write an exam, but they hate to come back after it is over. One solution is to work the exam right after they take it, but some might find that depressing since they don't know they will get partial credit for their silly errors.

Finally, use the fact that the class is small to work on any teaching techniques you tend to avoid in a larger class. Work one example like you normally would, then start the next one and have them finish it, then have them try the last one themselves. What I do is wait a few minutes and then wander around, telling people when they have the first step right (or wrong) and giving individual or group hints - or have the ones who have finished give a pointer to the entire class.

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