Gas station without pumps

2016 June 11

Teaching writing lab reports

Filed under: Circuits course — gasstationwithoutpumps @ 09:24
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Greg Jacobs, in his post Jacobs Physics: Report from the AP reading: Teach your class to write concise laboratory procedures. Please., asks high-school physics teachers to teach students how to write concisely:

Part (a) of our question asks for a description of a laboratory procedure. It could be answered in 20 words: “Use a meterstick to measure the height of a dropped ball before and after it bounces. Repeat for multiple heights.

“But oh, no … when America’s physics students are asked to describe a procedure, they go all Better Homes and Gardens Cookery Manual on us. Folks, it’s not necessary to tell me to gather the materials, nor to remind me to first obtain a ball and a wall to throw it against. Nor do you have to tell me that I’m going to record all data in a lab notebook, nor that I’m going to do anything carefully or exactly. Just get to the point—what should I measure, and how should I measure it.

Please don’t underestimate the emotional impact on the exam reader of being confronted with a wall of text. We have to grade over a hundred thousand exams. When we turn the page and see dense writing through which we have to wade to find the important bits that earn points, we figuratively—sometimes literally, especially near 5:00 PM—hit ourselves in the forehead. Now, we’re professionals, and I know that we all take pride in grading each exam appropriately to the rubric. Nevertheless, don’t you think it’s worth making things easy for us, when we be nearing brain fatigue? Just as good businesspeople make it easy for customers to give them money, a good physics student makes it easy for the grader to award points. 

Don’t think I’m making fun of or whining about students here. Writing a wall of text where a couple of sentences would suffice is a learned behavior. The students taking the AP exam are merely writing the same kinds of procedures that they’ve been writing in their own physics classes. It is thus our collective responsibility as physics teachers to teach conciseness.

As I’ve been spending far too much time this week grading an 11-cm-thick stack of design reports from my applied electronics course, I have considerable sympathy with Greg Jacobs’s view.

Technical writing is all about the 4 Cs: clear, correct, concise, and complete. Although there is always some tension between clarity and correctness, and between completeness and being concise, I generally find pretty high correlations between the four properties. Often, the very long reports are muddled, incomprehensible bundles of improperly applied factoids, while the essential information is missing entirely.

Part of the reason I have such a huge stack of papers to grade at the end of the quarter is that I have been giving “redo” grades for any errors in non-redundant representations (like schematic diagrams), putting a very high premium on correctness. For the class-D amplifier lab, 80% of the class had to redo the reports, mostly because they had not gotten the orientation of the FET transistors right in the schematics (a serious error that could lead to fires in the amplifier). I must have done a worse job at explaining the FET symbols—several times—than I thought, or maybe it is one of those things that people don’t learn unless they make a mistake and have it pointed out to them, repeatedly. I’ll be trying to fix the book and the lectures next year to reduce this problem.

I’ve also been down-grading students for lack of clarity (especially when the writing seems to indicate a lack of understanding, and not just inability to communicate) and for leaving out essential material (like not providing the schematics for their preamplifier as part of their amplifier lab report, not providing the parameters of the models they fit, or not providing the models they used at all). So clarity and completeness have had a fairly big impact on grades.

But I have not been giving bonus points for being concise, which I probably should start doing, as some students have started using a kitchen-sink approach, throwing in anything that might be tangentially related to the subject. Unfortunately, these are the students most likely to have unclear and incorrect reports, and they leave out the essential material in an attempt to throw in useless background, so their attempts at completeness generally backfire. I need to discourage this behavior, undoubtedly learned in middle school and high school, and get them to focus on the stuff that is unique to their design, rather than telling me Ohm’s Law or the voltage-divider formula over and over.

Love’s Labour’s Lost

Filed under: Uncategorized — gasstationwithoutpumps @ 07:54
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Boyet with the ladies of France

Boyet with the ladies of France

Last weekend, my wife and I took a trip down to Santa Barbara, for three purposes:

  • To see our son play Boyet in Love’s Labour’s Lost with Shakespeare in the Park
  • To bring him two large wheeled duffel bags that we had stored for him
  • To bring back about 100 pounds of his luggage

Earlier in the week, we had seen UCSC’s Shakes to Go do a very stripped down version of Love’s Labour’s Lost (45 minutes) at the elementary school where my wife works. It was interesting to contrast the two productions: one of which has to travel and be performed for elementary and middle-school audiences with no on-stage rehearsal, and the other which is only performed twice before a primarily adult audience.

The UCSC version had to be ruthlessly cut to fit in the class period schedules of schools, and almost all the verbal jests had to be jettisoned. Given that the play is full of now-obscure puns and sexual innuendo, there was not much left but the bare bones of the plot. It was still funny enough to amuse the students, but it was a bit unsatisfying for adults.  All 10 actors were theater majors, which is not surprising given the time commitment (a quarter of rehearsals, followed by a quarter with dozens of performances, each of which can take up a full morning).

The UCSB version was not cut as drastically (about twice as long with a running time of 1:28), but many of Berowne’s longer speeches were cut to the bone, and some jokes were lost.  The costuming was more elaborate for this production, and there was less double casting (17 actors instead of 10 makes a huge difference).  Several of the actors were not theater majors and one did not even have English as a native language, but the acting and directing was overall very good.

I took my cameras with me to UCSB and recorded the two performances of the play (with the permission of the director), so you can see for yourself how the production went (I think I did a better job of filming for the Sunday production than the Saturday one):



We were in a hurry on Saturday, so we took the Greyhound from Santa Cruz to Santa Barbara, making it in time to eat supper with him at Buddha Bowls before his 5:00 call.  Greyhound is the fastest public transit to Santa Barbara, but we prefer the comfort of the Coast Starlight train, even though it adds several hours to the trip, so we took the Coast Starlight and the Highway 17 Express back on Monday.

We had some time to kill between feeding him and the performance starting at 7:30, so we walked around the lagoon on the UCSB, which has quite a variety of birds (we saw egrets, cormorants, and a great blue heron).

I believe that this heron we saw is a great blue heron, based on pictures of herons I found on the web.

I believe that this heron we saw is a great blue heron, based on pictures of herons I found on the web.

On Sunday, we helped clean part of the apartment and pack most of his clothes and bedding, leaving him with enough to get through to his trip home on Wednesday.  He ended up with an easily managed load of luggage, after he stored his bicycle with the police for the summer (a very handy service that cuts down on bike theft and abandoned bikes).

The large rolling duffel bag that we brought home for him was overloaded (68 pounds, compared to Amtrak’s 50lb limit), so I had to rearrange the luggage at the train station on Monday—I’d anticipated this need, so it only took a couple of minutes to remove the already packed pannier from the duffel, and transfer a few clothes to the carry-on suitcase.

One big difference from when I was a student is that he had practically no books—what few textbooks he’d had this year he’d been able to get electronically, and most of his recreational reading is from the web rather than on paper.

We had a little time to kill Sunday afternoon while he caught up on sleep (there’d been a cast party Sat night), so we looked at the newly refurbished library on the UCSB campus. The facilities seem quite nice, but were overloaded on the weekend before finals.  There seem to be enough computers and power outlets, but not enough WiFi bandwidth (we heard students talking about going elsewhere to study, because of problems with the WiFi).

2016 June 8

End of quarter feedback

Filed under: Circuits course,Data acquisition — gasstationwithoutpumps @ 22:34
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Before the last day of class, I sent my students an email message with some requests for feedback:

  1. The group tutor would like students to give him some written feedback on his performance as a group tutor, to improve his teaching skills.  This feedback goes only to him and does not affect his pay nor his job evaluation.
    The group tutor designed his own paper feedback forms and collected them from the students. Paper forms are a great way to increase participation in the feedback process, but I did not have the time or energy to do that this quarter. I don’t expect to see his feedback—it really was just for his benefit—unless he wants to discuss some of it with me.
  2. Parts and tools.  What parts and tools did you not use? what should have been included that wasn’t? What can be done to improve the parts kit next year?  I need to have the parts kit for BME 51A specified by the end of September, so I’ll be thinking about it over the summer.
    The students were upset at the resistor assortment not having a fairly uniform spacing of resistors. It would have been more useful to have the E6 spacing from 1Ω to 10MΩ (43 different values) than to have lots of odd sizes and nothing from  82kΩ to 1MΩ (the most useful part of the range for us). I’ll definitely be looking for a better resistor assortment next year, even if it costs more.
    I was particularly interested in whether the $10 handheld digital multimeter which I added to the parts and tools kit this year was worthwhile. A little less than half the class had used, but few felt strongly either way about including it (only 4 hands voted to drop it and only 4 to keep it—the rest were in the middle). I think that I either need to work it more directly into assignments (having students do some measuring at home in prelabs) or drop it. Best, perhaps, is to have it available as an optional add-on, but BELS is not happy with such arrangements.
  3. Lab order. When I split the course into BME 51A and 51B next year, one of the amplifier labs will end up in BME 51A.  Which one should it be?  I’m wondering whether it would be better to start with pressure-sensor lab, moving the microphone lab to BME 51B.  If I do that, what should the order of the labs be?
    Students agreed that the mic lab would not be the best way to end BME 51A, and thought that the pressure-sensor lab was more straightforward. They also would have preferred the audio labs (mic, speaker, pre-amp, and power amp) to be grouped together into a coherent unit. That may require even more radical reorganization than I had originally planned, since it would move not just 1 lab, but 2.5 labs from the first half to the second half, necessitating moving at least one more amplifier lab into the first half. That would also put many of the measurement and modeling labs (mic, loudspeaker, electrodes) into the second half, but I think we need to keep the modeling spread out.
    I can see I’ll need to give the schedule a lot of thought this summer.
    Students liked having the EKG last as a summary of almost everything else.
  4. Ideas for replacement labs.  Were there any labs you would have liked to have done that we didn’t have time for?  What should be removed to make room for them?  Is there any way to make a more “creative” lab, where students pick a design goal that is less tightly constrained than the current labs? Remember that the course is trying to serve all 4 concentrations, which means a wide variety of interests and skill sets.
    There were no comments in class on this topic.
  5. Book. I’ll be working on the book this summer. Which chapters need the most work (either new material or rewrites)?
    There were no comments in class on this topic. Email later said that most of the things they could think of were already in my to-do notes in the margins.
  6. Videos.  Was the oscilloscope video useful?  Should I make more lab equipment tutorial videos this summer? Any other short tutorial videos that might help?  (Even crummy videos take a lot of work, so I’d rather not spend a lot of time on ones that aren’t useful.)
    There were no comments in class on this topic, but I think I’m going to try to do some more videos with my son as narrator, anyway. One email later on said that the video was useful, but in-lab help from the group tutor or me was more useful. I agree with that, but it gets hard to scale up the personal contact, so I had to supplement with videos this year—I still plan to give a lot of oscilloscope direct help to pairs of students in labs, but the video is better than whole-class demos.
  7. Prelabs. Were the prelabs useful for preparing for the labs? Is there a way to make them more useful (and have a higher fraction of the students completing them)? The pace next year will be less hectic, and there should be more opportunity for lectures and questions before the prelabs are due.
    Students definitely felt the need for more time and more preparatory lectures before doing the prelabs. A lot of the prelabs were overwhelming to the students, and even I felt that the prelab before the preamp lab was much too long.  The slower pace next year and higher lecture/lab ratio should help. Those who did the prelabs found them very useful preparation for the labs, but I definitely need to rework the book to make the prelab exercises more obviously useful to the students.
  8. PteroDAQ. What improvements should be made to PteroDAQ? Do you foresee any uses for PteroDAQ in your future work?
    There were no comments in class on this topic, but a later suggestion was to add optional digital filtering to channels. That would be a useful addition, but one of the design goals of PteroDAQ was to avoid package dependencies, using only packages which were required parts of a Python installation. The scipy signal-processing package is very nice, but is not part of the standard distribution. Students with anaconda or enthought distributions (which include scipy) had more installation and update problems than those who just used the installation, in part because they ended up with multiple Python installations that had different libraries installed, and often ended up updating the wrong one.
  9. Gnuplot. Were the almost weekly lectures on gnuplot and model fitting useful?  Do you have a better appreciation of how to choose models for your data and fit the models to the data? Do you foresee using gnuplot in preparing reports for other classes or projects?
    There were no comments in class on this topic, but later email indicated that gnuplot was useful and they appreciated having freeware for high-quality graphics, but that more time needs to be spent on modeling and gnuplot—one student even suggested a full course on gnuplot and fitting models. There is a scientific visualization course being taught next year, using matplotlib in Python, though, not gnuplot. I like matplotlib also, but it requires more programming skill than gnuplot, and the model-fitting libraries available for Python are definitely far harder to use than gnuplot.
  10. Lab partners. Did the forced partner practice work for you? The intent was manifold: cutting the grading in half, having someone to talk with to reduce confusion, having someone to check your work, getting to know lots of your fellow students and their working styles (both in preparation for later group projects with them, and to get a better feel for the diversity of people you will work with in industry or academia), making sure that no one was able to freeload consistently, … .  Which of these intents worked, which didn’t?
    There were no comments in class on this topic. Later comments found the partners very useful—working alone on one lab was really tough, but that changing partners often was a good idea (one flaky partner in the quarter was enough, and being forced to have different partners lead to more of a taste of what it is like to work with different people).
  11. Lab time. Was 6 hours of lab a week enough time with the equipment?  Which labs needed more time? Is there a way to make lab time be used more efficiently, since it is a scarce resource on campus? Is there a way to move more of the lab activity out of the lab space?
    There were no comments in class on this topic. Later comments said that the lab time was enough when students came prepared, but that it was very useful to have an extra weekend lab time for overflow, especially for the soldering labs, which took more time to do and debug.  This year, having the reports due before that overflow lab time probably resulted in a number of unnecessary REDO grades, increasing both my grading workload and student stress. If I can make the reports due after students have a chance at the overflow time, things might work more smoothly.
  12. Electronics hobbyists. One of my less official goals in the course is to turn a few of the students each year into electronics hobbyists—people who will try to design or build small electronic things because it’s fun.  Did I have any success with that this year?
    As the feedback session was winding down, I had the students vote on 4 topics that I could talk with them about: motors (stepper motors, brushless motors, …), switching power supplies, internals of PteroDAQ, and resources for hobbyist electronics. Somewhat to my surprise, the resources for hobbyist electronics were the overwhelming favorite (about half the class), so I think that I did have some success in getting a number of students started on hobbyist electronics.  I don’t know how many will stick with it, but that’s ok—just having gotten them started was all I was aiming at.
    Students also suggested that the book contain more suggestions for hobbyist additions to go beyond the labs.

2016 June 5

Non-academic science career information aggregator

Filed under: Uncategorized — gasstationwithoutpumps @ 04:02
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I was recently pointed to a collection of links that many science and engineering grad students may find useful: The Prodigal Academic: Non-academic science career information aggregator

Non-academic science career information aggregator

Below is a list of websites that may be helpful.of interest to scientists looking outside of academia. This is by no means a complete list, so if you know of other useful sites, let me know, and I will add them in!

Blog posts about non-academic careers: …

CV vs resume: …

Possibly interesting career guidance: …

Interesting non-academic science online discussion: …

I’ve not copied the actual links, just the headers, as I don’t want to steal content from The Prodigal Academic, but just point to the web page as a useful resource. Most grad students in the sciences have to seek jobs outside academia, but their mentors are, for the most part, clueless about life outside academia (me included).

In engineering, the working degree is the MS, not the PhD (which is primarily for those seeking academic positions, or with a few small industrial or government research labs). Most engineering faculty are aware of the MS (“real” job) vs PhD (academic job) distinction, but still advise their students towards the path they themselves took.  Since many engineering faculty did some time in industry before turning to academia, there are often mentors around who can suggest different career paths.

In science fields. most faculty have been in academia their whole lives and can’t provide any useful information about other choices.  (Although I’m an engineering faculty member, I’ve also been in academia my whole life, so I can identify with the science faculty here.)

One major distinction between science and engineering is that in most science fields, the PhD is a requirement even for entry-level jobs, because of the huge over-production of PhDs in those fields. Biomedical research is probably the worst, in that several years of postdoc “training” are expected, so that many do not get jobs with any security of  employment until they are in their 40s.  (And by “security of employment”, I don’t mean tenure—I mean a job that doesn’t have defined end date before you even start work.) Huge numbers of scientists work on short-term contracts (2 years is common for a postdoc contract) with little expectation of the contracts turning into longer-term jobs.

So students need to be looking beyond their faculty advisers for advice about what to do with their degrees, and The Prodigal Academic has collected a number of useful posts with advice that many faculty members can’t give.  I plan to send the link to mailing lists of students, who might benefit from more knowledge of alternatives to the academic careers of their faculty advisers.

2016 June 1

Poll data and electability

Filed under: Uncategorized — gasstationwithoutpumps @ 19:03
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I’m a bit worried about the possibility that Donald Trump might win the Presidential election.  I don’t personally see how any sane person could vote for him, but US politics never seems to have been ruled by sanity.

I was looking at the poll summaries at RealClearPolitics:

I hope that the “superdelegates” at the Democratic national convention are watching these polls also and doing everything they can to make sure that Trump is not elected, even if it means that their favorite candidate doesn’t get the nomination.

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