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2016 June 8

End of quarter feedback

Filed under: Circuits course,Data acquisition — gasstationwithoutpumps @ 22:34
Tags: , ,

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.

2014 March 19

Last day of freshman design seminar

Filed under: freshman design seminar — gasstationwithoutpumps @ 08:35
Tags: ,

Monday was the last day of class for the freshman design seminar, though I’ll see the students again on Thursday, when they turn in their final reports and show me what (if anything) they’ve managed to do on their prototypes.

I got their penultimate drafts yesterday, and I was a bit disappointed. A couple of the groups do not seem to have gotten the idea of revising drafts—they seem to have started from scratch on each draft and turned in yet another first draft. I don’t want them starting over each time—I want them to fix what they have and add more to it each time.  The drafts are still woefully lacking in detail. They mention calculations, then don’t show them to me (have they done them? I can’t tell). There are very few pictures of prototypes, schematics, or plots of theoretical results (like voltage as a function of temperature for their thermistor circuits).

Ah well, the results are not so bad that anyone is failing, and I think that the students have learned a lot this quarter, even if they can’t quite pull together a coherent report yet. I looks like everyone will be in the B– to B+ range, but I won’t know where until I see the final reports. Of course, if any group manages to build an even marginally functional prototype, their grades will go up, but the time constraints make that fairly unlikely at this point.

I did do an “exit survey” on the last day of class.  The survey was anonymous, and I don’t know the students’ handwriting or pen choices, so I really have no idea who wrote what. That means I can’t correlate anything with class performance or gender, but that is less important than getting honest responses through anonymity. Here are the questions and a brief summary of the answers (extracting a few key phrases from some of the longer answers and fixing some grammar):

  1.  As a result of this course, did your interest in bioengineering as a field increase, decrease, or stay about the same?
    Decrease: 2
    Same: 1
    Increase: 8So one of the main goals was successful. Neither of the students with a decrease in interest seemed to be bitter about the class—their answers on the other questions were helpful and indicated that the course had worked for them—they had just realized that bioengineering was not a good fit for them.
  2. Was the workload appropriate for a 2-unit course (about 6  hours/week, including class time)?  Too much? Too little?
    Too much: 5
    About right: 5
    Too little: 0
    One said “about right in the beginning, too much at the end”, which is what my sense was—the students left their prototyping and detailed design too late. I think I need to have an early deadline for a mockup at least, so that they get into the details of the design sooner. There was too much “big picture” thinking and not enough getting down to details.Note that the “too much work” did not correlate with the increase/decrease of interest in bioengineering.  Also, the “about right” group were spread out from “could have a little more” to “bordering on too much”.
  3. Did any of your skills (web search, technical reading, technical writing, subdividing problems, design, prototyping, programming,  working in groups, … ) improve as a result of this course? If  so, which ones?
    Web search: 5
    Finding parts on the web: 1
    Finding data sheets: 1
    Researching online: 1
    Technical reading: 3
    Working in groups: 2
    Prototyping: 6
    Engineer way of thinking: 1
    Design: 3
    Dividing problems into subproblems: 3
    Programming: 6
    3D software skills: 1
    Writing proposals: 1
    Report writing: 1
    Technical writing: 1Students seemed to get at least some of what I hoped for from the class, but I think I’ll want to increase both the programming and prototyping next year. Those seem to have been memorable for students, and we didn’t do enough of either one.
  4. What were the most important or interesting things you learned as a result of this class?Program the Arduino
    Using Arduino and other electronic hardware
    Prototyping, writing, dividing problems into subproblems.
    A project can be divided in a group.
    Class made me think in a way I never thought before.
    What engineers do with a data sheet, how they make design reports, also advice on classes to take.
    Details of how instruments work (spectrometer, colorimeter, and projects for class)—interesting to find out how common appliances like light switches, thermostats, … work.
    Steps and processes for designing a bioengineering tool.
    How to be an engineer.
    Introduction to programming.
    The World of Data Sheets.

    Again, a lot saw the intro to programming as very valuable, despite how little we spent on it. I think that component would be worth increasing next year (assuming that the class composition is similar).

  5. What worked well in the class and should be retained next year?Learning to program Arduino and hooking up parts to it.
    Pushing us to do research on our own.
    Prototyping, though we didn’t get to finish. Also more programming assignments.
    Introduction of different topics in the beginning of class worked well. I’m not sure what is meant by that.
    Beginning with spectrometer then building to more complex design concepts.
    The Arduino should be brought up again.
    Designs of spectrometer and colorimeter should be retained next year.
    Teaching the process of how to build spectrometers.
    The project; programming; critical thinking.
    Work with Arduinos.
    I’d been concerned about the spectrometers taking up som much time at the beginning, when students started out not knowing what they were. But it seems to have been memorable, so we might do a little more with it next year. I might want to start with a simpler colorimeter, though, then work up to a spectrometer.
  6. What worked poorly and should be discarded or greatly modified?Designing spectrometers and colorimeters was cool but it barely related to our final project.
    A more set lecture plan would give us more information about programming.
    The timing is planned poorly. With better management the class could achieve more.
    The class could be more organized and better suited to freshmen.
    Beginning the actual design sooner.
    The class didn’t seem to have any learning objectives.
    More background and basics on programming, machines, circuitry, and just overall expectations.
    The final projects should be more narrow choices, so they don’t take so much time to build.
    The workload is too much.
    Design the colorimeter before the spectrometer.
    Too much time spent writing up designs without a “contract to fail”—it’s the failures and mistakes you make that make you a better designer/engineer.

    Most of the negatives were about planning and organization. The timing for the course was not really planned—I was feeling my way through the course, trying to figure out what they knew already and what they needed. Everything took much longer than I expected, because I kept overestimating their knowledge, skills, and independence. I’ll have better timing next year, when I should have a better idea what to expect.

    I agree that the simpler colorimeter should come before the spectrometer. I think that I’ll have them do a physical mockup of a colorimeter out of cardboard or foamcore and develop the sensing circuitry and Arduino interface sooner.

    I also agree that starting the projects earlier and having more guidance on the project choices would be helpful. Unfortunately, the day they picked projects was the one where I was ill, and the group tutor guided them to more ambitious projects than I would have (ones he wanted to do as a senior, I suspect).

    I bristled a little bit about the “didn’t seem to have any learning objectives”. If anything, I had far too many objectives (see the skills list in question 3). I suppose that students who are used to a highly structured school where every lesson is tied to a particular content standard may have more trouble with learning objectives that are more about increasing their independent learning than about specific content. I did try to make it clear to students that my goal was to shift their way of thinking and to increase their ability to learn independently rather than to impart any specific content. We got a fair amount of content in anyway, though it was a rather randomly assorted mix of big engineering concepts and little factoids—the factoids were mainly to support whatever design task we were currently facing and there were a lot of them (because engineering is often about the details).

    I’m torn about the “more background” request. I think that they could indeed have achieved more if I’d given them more scaffolding, and there were a few times when I felt that I should have given them a bit more. But a big chunk of what I was trying to do was to shake them out of the “echo what the teacher said” mode that they’ve had drilled into them for the past 12 years. I was trying to get them to realize that they can learn things by finding the information themselves and reading it. But I do need to give them some more help in the beginning on learning how to find information, which means having the reference librarians give them a good search lesson early in the quarter. I should probably also put together some more search-and-learn exercises, like the ones I had about finding and reading data sheets.

  7. There are a lot of changes in the course that I’d like to see,  but I’d like to know what changes you’d like to see.
    More physical designs and fewer write-ups.
    More background on circuitry and programming. Often found myself working considerably more than 6 hours a week to fully research a field/skill to understand how to design a project. This is beneficial in terms of teaching students independence and accountability, but it does result in a heavier than expected workload for a 2-unit course.
    Less work, more time on the project.
    Make it a 5-unit course so that students have time to learn properly.
    Make class half lecture half discussion. Final projects should be started earlier.
    Design projects should start earlier in the quarter.
    Have students keep a design journal. Begin the design sooner.
    More organization. More in-depth lectures. More explanations of expectations. More interaction with other students. More time spent on project (start earlier).
    Start project earlier, introduce resources first, and focus on one project.
    Need access to tools and a space to prototype in.
    Start on design project sooner so we have enough time to put together a decent prototype.

    I agree whole-heartedly with the need to start prototyping the project sooner. But just starting earlier wouldn’t really solve the problem. Many students played around with vague ideas for weeks and didn’t start looking at parts until the last week of the quarter. It might help if we had some physical prototyping before they selected a project, and if I required a non-functional mockup the week after they selected their design goal. Giving them a schedule with deadlines for various tasks that includes sufficient lead time for ordering parts would probably help—they still need scaffolding for time management and project planning.

    I had originally planned to have the whole class focus on one project, in competing/cooperating teams, but my illness on the day they selected projects and inadequate communication between me and the group tutor resulted in him encouraging three different projects. The students may have been more interested in the particular projects they selected, but it meant that whole-class discussions of project status and how to tackle design problems were less fruitful—people tended to tune out on when other projects were discussed.

    I’m not going to cut back on the write-ups, though. The students seriously need a lot more work on their writing. I don’t think that the writing instructors on campus have a clue about technical writing, so aren’t providing them the practice and feedback that they need. The huge lecture classes in beginning science and engineering don’t help either—they again get almost no writing practice with feedback.

    I had thought about the possibility of making this a 5-unit course, but there isn’t really room for another 5-unit course in their schedules—delaying their foundation courses needed to declare the major would not be a service to them. A 2-unit course added to their 15–17 units normally taken is about all there is room for, unless some other course were removed from their schedules. In the curriculum redesign this year, I already pared out as many beginning courses as I could to make room for more advanced courses—I don’t think that this course is high enough value to remove one of the more advanced ones.

Overall, I’m pretty pleased with the feedback from the class. They got a lot of the things out of the class, even though it only represents about 1% of their college education (2 units out of about 200 for engineering students). The things they criticized were mostly things that I found fault with myself: insufficient physical prototyping, needing more time teaching circuits and programming, needing better scheduling.  The tone of the feedback seemed positive to me (and I’m unduly sensitive to negative feedback), so I’m going to tentatively declare the class successful.  I’ll be re-reading these notes next December, when I’m putting together the syllabus and web page for next year’s offering.

The feedback did not take up the full class slot—we also had time for some whole-group discussion of status and group meetings for trying to finalize the projects.

2013 August 4

What teachers need to look for

Filed under: Uncategorized — gasstationwithoutpumps @ 13:29
Tags: , , ,

Grant Wiggins, in his post Better seeing what we don’t see as we teach, gives some good advice to teachers about observing their students.  It is wrapped in too much sports metaphor for my taste, which makes the condensed summary a bit hard to understand:

  • Look beyond the “yesses” and head nods. 
  • Look “off the ball.”
  • Spot the “first foul.”
  • Listen for the ‘dog that does not bark’.
  • Look for what the quiz does not show.
  • Who are my “starters”?
  • Feedback on your feedback.
  • What notes do they take?
  • Call a time-out.
  • Assess formatively every few minutes.
  • Ask for feedback.

There was no pithy quote to pull out to summarize the post.  The basic idea is that most teachers do not pay enough attention to the students who are not actively providing feedback, and that it requires concerted, conscious effort to become aware of the students who are either not participating or who are giving the feedback that they think you want, rather than honest assessment of their understanding.  For the past few years I’ve been working on improving my awareness of the students having trouble with the material and involving them more in the class, but I still have a ways to go.

For me, the biggest change I could make is to ask for formative assessment from the whole class every few minutes. (Grant suggests roughly 10-minute intervals.) Although the logistics of clickers, cards, or hand signs is pretty simple for getting feedback on multiple choice questions, I find it difficult to come up with multiple choice questions that tell me anything useful—coming up with them on the fly during a class seems particularly challenging.

The classes I teach are unusual enough that there isn’t a big body of predigested teacher support material for me to lean on—I have to come up with everything myself.  This doesn’t cause me any difficulty for lectures—I know the material well enough that I generally only need a couple of words of notes to remind me what to talk about, but building assessments takes me a long time.  I may spend a week or more full-time devising and writing a programming assignment or a lab assignment, and I’ve mostly given up on writing timed tests (though I used one in the Applied Circuits class and will do so again next year).

I particularly find it difficult to come up with small questions, of the sort that students can reasonably answer in a minute or two, which is what I’d need for in-class feedback of the type Grant Wiggins suggests.  The homework and lab assignments are almost always of the size that it takes 3–10 hours to do them.  I’ll be trying in the coming year to devise at least one tiny question for each class session—which will probably take me longer than the class sessions themselves.  I’ll record the questions in this blog after I’ve used them in class, so that I’ll be able to use them in classes in future.

2013 March 20

Bar exam for circuits class

Filed under: Circuits course — gasstationwithoutpumps @ 13:45
Tags: , , , ,
Front of T-shirt

Front of T-shirt

Back of T-shirt.  The silkscreen is intended as a white silkscreen over a black T-shirt.

Back of T-shirt. The silkscreen is intended as a white silkscreen over a black T-shirt.

Because the applied circuits course did not have a final exam, the students asked if we could get together at a bar for a beer during the exam time instead (which my son quipped should be considered a “bar exam”).  Because we had some underage students in the class, I chose Caffe Pergolesi as a site (they serve beer but also coffee, hot chocolate, and coffee-house snacks).  The café was surprisingly crowded for 4 p.m. on a Tuesday (probably due to it being the first day of exam week), and I had to sit out on the deck, because there were no tables available inside.  At first I was a bit worried that no one would show up (a common problem for parties I’ve tried to have in the past, so I’ve stopped attempting to have parties), especially when no one was there by 4:10.  But the students started trickling in and we eventually had all the students in the class—even those who had sent e-mail saying they couldn’t make it.

I showed the students the T-shirt design, modified according to their suggestions the day before, and they approved it.  I still need to check with the screen printer that the SVG files I have will work—I think that the back is ok (it is a single black rectangle for the T-shirt with a single path for the white layer on top), but I’m worried about the front. The text, slug, and small thought bubbles should be fine, but the black images on the large thought bubble are currently objects on top of the white thought bubble, and I’ve not figured out how to get Inkscape to make them cuts through the thought bubble to the black T-shirt underneath.  The Inkscape “path difference” operation, which worked for the back of the T-shirt doesn’t do the right thing with these images.  So far I’ve gotten 7 orders for T-shirts from the class (including one for me and one for my son), and I’m hoping for another 5 or 6 to amortize the setup costs.  I think that we’ll have about $90 in setup plus $12/shirt, so 7 shirts would be about $25 each and 12 shirts would be about $20 each (long sleeve shirts a couple of bucks more).

I used the time to get feedback from the class about how it should be modified in future, starting from a handout I’d given them the day before.  Here are some of my notes from the discussion.  If I’ve missed anything, I hope that students will send me e-mail.

  • Parts and tools to eliminate:  velcro cable ties (unused), long-nose pliers (low quality and not used), thermometers (change to lab equipment), LEDs (not used).
  • Parts and tools to add: inductor for class D amplifier, soldering iron.  A soldering station like the one I have (and similar to the ones they used in the lab this year) would add $20 to the cost of the course.
  • It may be worthwhile upgrading the screwdriver set, as the under $2 set was really low-quality and some of the screwdrivers failed (blade slipped in handle, so that screwdriver did not turn with handle).
  • I had been worried about the high price for the large assortment of resistors ($13.35 for 1120 resistors, 10 each of 112 sizes), but the students liked that they always had whatever resistor size they needed, and were contemptuous of the approach used in EE101 of providing students with only about 20 resistors of the precise sizes that the faculty had decided the students would use.
  • One student suggested having a protoboard for designing the class D amplifier, since that is something they might want to keep.  I’ll have to think about that, as it doesn’t strike me as an immediate win, though I can see wanting to keep the power amplifier.  One problem is that the class-D amplifier is not as generic a project as the instrumentation amplifiers, so it is harder to come up with a general-purpose protoboard. Also, most students ended up having to do a lot of experimenting to get the biasing to work out for the power FETs, which could be difficult on a PC board.  The class-D amplifier also needs a bit more space than the two instrumentation amp projects, so a PC board for it would have to be bigger ($2/board instead of $1/board).  Having the same protoboard for both the pressure-sensor lab and the EKG lab meant that time spent learning how to use the protoboard was amortized over two projects, which would not be the case for a special-purpose power-amp board.
  • One student suggested adding a voltmeter for home use, but the problem there is that voltmeters that can read AC voltage correctly for 100kHz signals are mostly in the $100-and-up range.  The $5 voltmeters that could be put in a kit for everyone to buy are not useful for some of the labs.
  • Students suggested that the first quiz should be given as homework instead of a quiz—a good idea, since the questions were too hard for the students as a quiz, and having time to think about them and discuss them with each other would lead to more learning.
  • The students do not think that adding a textbook to the class would help, but being directed to the All about Circuits readings more often (including the worksheets) might help.  They generally found the Wikipedia articles too detailed and too broad to be helpful in learning the material.  They got fairly good at at searching the web for keywords and finding lecture powerpoints from other courses that were relevant.  No one found a steady source of good material though—the searches tended to find different sources for each topic.  The students reported being able to find data sheets fairly easily and consulting them fairly often, so at least one of the goals of the course was met.
  • One student reported that soldering the instrumentation amp for the pressure sensor lab seemed a bit pointless to some, as they don’t buy the pressure sensors to connect to, so a permanent board is not much use. The benefits (soldering practice and less noise pickup from long wires) may not justify the extra effort of soldering.
  • We discussed re-ordering the labs, moving the electrode measuring and modeling lab later, and the sampling and aliasing lab earlier.  A possible new order is
    1. Thermistor
    2. Sampling and aliasing
    3. Microphone
    4. Audio amp
    5. Hysteresis oscillator
    6. FET and phototransistor
    7. Electrode modeling
    8. Pressure sensor
    9. Class-D power amplifier
    10. EKG

    That order could cause some difficulty for the sampling lab, which needs RC filter design (hence complex impedance), so maybe swapping the mic and sampling labs would be better.

  • We also discussed the idea of having 2 labs a week (both Tuesday and Thursday), with a data analysis day in between (to teach gnuplot scripting and fitting models).  None of the students had done model fitting (other than straight lines) in any other course, so this is a skill worth spending a bit more time on in class.  Having 2 105-minute labs a week (the standard TTh time slot) would probably not be enough, as that is barely more than the 3-hour lab weekly lab this quarter, and the setup time would probably eliminate any gains.  I’d probably have to schedule 2 time slots per lab (say 10–1:45, 2–5:45, or 6–9:45).  If the course grows to full size, I would be spending 8–12 hours in the lab on Tuesdays and Thursdays, without break.
  • If I do have more lab time next year, I could start a little slower, using the first week to have students learn to identify all the parts, mark the capacitor bags with the capacitor sizes, learn to use the ohmmeter and power supplies, … .  Some of the later labs would have no more time than this year, but some of them needed no extra time.
  • Students would like several explanations to come earlier in the course relative to the labs—FETs before the microphone lab, PN junctions and phototransistors before the tinkering lab, block diagrams earlier in the course, … .  I agree, and moving the first labs a week later could help with that.  I’ll be doing a day-by-day topic planner before resubmitting the course approval paperwork.  One problem with teaching block diagrams earlier is that—like outlining in writing—they’re really only useful once the complexity of the design gets high enough that subdividing the problem is useful.
  • The students were pretty pleased with the data logger software that my son wrote.  The biggest complaint was about the logger freezing when recording a long run at high sampling rate (a known problem).  I believe that he is developing a fix for that problem, which will generally result in faster live charts.  Students also like the idea of being able to produce eps, pdf, png, or svg output directly from the data logger, so that they didn’t feel the need to make screenshots.  Providing starter gnuplot scripts (which they could then add to in order to do model fitting) was also attractive to them.  There was one request for icon-based executables (avoiding the command line), but I actually prefer for engineering students to have to learn to use command-line tools—I was shocked that they had gotten to their senior year and had not learned how to use command lines.
  • Students thought that the current prereqs for the course were fine—they did not see a need to add a programming prereq, unless the course was changed in a major way to include Arduino programming (which I’m not tempted to do, as there are already courses on campus covering that).  They did think that the course needed to remain an upper-division course, but that sophomores might be able to handle it by the Spring (which is when it will be scheduled in future).
  • Some students thought that the course could be reduced to 9 labs (from 10)—mainly to reduce the number of reports written.  I think that we could achieve that by putting the microphone lab and audio amp lab together and having 3 lab sessions with only one report.  We might be able to combine the hysteresis lab and the tinkering (FET and phototransistor) lab into one report also.
  • The students really liked the undergrad group tutor we had—saying that he was the best TA they’d ever had.  I believe that he is graduating this year (as are all the students in the course), so I don’t know whether we’ll be able to get as good an assistant next year.
  • Students liked having learned gnuplot, though they initially struggled with it and hated it.  Once they got past the initial learning, they found it useful for senior theses and courses other than the circuits course.
  • Overall, students thought that the class had met most of the learning goals I had set for it, and several of them wished the course had been available to them earlier—some of them might even have opted for the bioelectronics track (they were all biomolecular track), had they taken this course early enough (and if EE would accept it as prereq to the other upper-division courses needed for bioelectronics).  I’m certainly going to try to convince the EE faculty that this course can serve as more than adequate preparation for courses like signals and systems (better than the existing circuits course).

The students in the class gave me two bottles of wine as a thank-you for the course—that is a first for me in 30 years of being a professor.  Most often students are glad to have survived my courses, but don’t generally appreciate them until several years later.

The student appreciation certainly isn’t because I’ve been grading leniently—the class is mostly in the B- to B+ range, and some had to go through 2 or 3 drafts of the lab reports to get to even that level. There may be one or two A- grades (I still have the last 2 lab reports to grade, so I don’t know yet—I’m hopeful, but I’m not going to give out As unless the work justifies them).

I think that the recognized that I was genuinely interested not just in the material but in getting them to do real engineering design and to think like engineers.  Several have taken to heart the “try it and see” mantra and have learned to appreciate the value of “sanity checks”.  I think that the value of a UC education lies mainly in these high-contact “artisanal” courses, not in the mega-lectures and cookbook labs that they have mostly been suffering through.  (To be fair, many of them are working on senior theses in various faculty labs, so they have had high-contact educational experiences—just not structured as a required course.)


2011 December 26

Always negative

Filed under: Uncategorized — gasstationwithoutpumps @ 19:27
Tags: , , , , ,

On a blog I comment on, which I won’t point to here, since I don’t want to cause any embarrassment for the blogger, I have been accused of always posting something negative in the comments and of being “a blog terrorist who comes to drop bombs on everything anyone says, regardless of the nature of the content.”

There is some truth to the first part of that criticism, but not to the second.  I’ve never been particularly good at seeing and praising the good points of something, and even minor flaws in reasoning or execution of an idea often stand out in high relief to me.  This goes for my own work, not just other people’s work, which probably contributes the writer’s block I’ve been suffering on research papers. It is not, however, my intention to injure or insult others or to start flame wars.  When I criticize, it is never “regardless of the nature of the content”—it is almost always a direct response to the content and an attempt to clarify a confusion or provide some insight.

I am aware that I would probably be a happier and more successful person if I saw the positive sides of things more and the flaws less.  There has even been research that shows that optimists have a greater life expectancy than pessimists (though it is not clear that there is a causal connection—both optimism and longer life may be effects of some other variable). [Optimists vs pessimists: survival rate among medical patients over a 30-year period. T Maruta, R C Colligan, Malinchoc, and K P Offord. doi: 10.4065/​75.2.140Mayo Clinic Proceedings.February 2000 vol. 75 no. 2 140-143] I’ve not heard of any evidence that it easy, or even possible, to change oneself from a pessimist to an optimist, so I have not attempted to make such a major change in myself.

Because current American culture calls for stroking people’s egos (“if you don’t have anything nice to say, don’t say anything at all”), I am often constrained either to be silent or to be considered rude.  This makes me unsuitable for management positions (where being polite to incompetents both above and below one in the hierarchy is considered essential—more important than competence).  I can generally be polite to students and staff, but I have a hard time tolerating stupidity or self-serving behavior in those above me in a hierarchy, and I have little patience for mindless bureaucracy, where rules are formulated without thinking about their consequences and then enforced rigorously even though they have the opposite effect of the original intent.

My tendency to see the negative does affect my grading of student work.  I have not been able to consistently follow the commonly given advice of finding something praiseworthy in a piece of work before offering any criticisms.  I’ve made the attempt many times, but only succeeded occasionally.  What I have generally been able to do, however, is to avoid using vague words like “bad” and “good”, but to make each comment on a student assignment or in an article I’m refereeing be very specific, pointing out the problems that need to be corrected as clearly as possible.  My overall assessment of how serious the flaws were is summarized in the grade on the assignment (or in a one-sentence recommendation for a referee report).  On all assignments except term papers due at the end of the quarter, I allow students to rework the assignment, attempting to correct the flaws.  I do warn students that I expect more than just incorporating copy editing I’ve done for them—reworked assignments are held to a somewhat higher standard than homework turned in only once.  If I’ve pointed out some grammatical errors, I expect them to go through their entire paper, looking for other instances of similar errors.  If I point out an off-by-one error in their code, I expect the comments for the relevant variables and tests to be clarified, so that anyone reading the code would have been able to spot the off-by-one error, not just a fix to the number.  I also expect them to check all their other loops for off-by-one errors, as well as whatever other sanity checks should have been applied the first time.

Although my generally negative comments on assignments come as a bit of a shock to some students, they usually end up appreciating the detailed feedback.  I have had some students (seniors in college) tell me that no one in their previous education had ever read their writing that carefully and given them such useful feedback.  (These were not students just telling me what I wanted to hear, since they were coming back to tell me this after the course was over and the grades were in.)  I believe that providing such detailed feedback is one of my primary teaching roles as a professor, so I usually do my own grading for courses (avoiding large classes, where that would not be feasible).

It is my belief that the way to express high expectations to students is, first, to have high expectations (no grade inflation, no mercy pass) and, second, to give students detailed feedback on what they need to fix to meet your expectations.  Note that detailed feedback is inconsistent with the philosophy  “if you don’t have anything nice to say, don’t say anything at all.” When a piece of work is unacceptably bad, students need to know that, not get stroked just for having turned something in (unless just turning something in is a high expectation for that student in that class—I’m fortunate not to have to deal with that situation).

Detailed feedback is key, not detailed instructions.  When I started teaching I provided very detailed assignments, trying to warn students of many of the pitfalls they should avoid.  Although I still do a little of this, I’ve scaled way back, since it did not seem to help.  The students who most needed the warnings suffered from TLDR (too long, didn’t read) on long assignments.  I’ve worked in recent years to get shorter, clearer assignments, with only a few verbal warnings in class, and to provide detailed feedback on the pitfalls after students have fallen into them.  They seem to learn better from making the mistake and correcting it than from being warned about it repeatedly.

Despite the value I put on detailed feedback, I have trouble reading potentially negative comments on my own work (referee remarks on papers, panel remarks on grants, student feedback on courses).  I generally need to be in a fairly relaxed state to be able to read them at all, and I usually have to read them repeatedly on separate days to be able to absorb them and process them rationally (and not just emotionally).  Even when the comments are favorable, I generally don’t absorb them in any detail on first reading.  Because the student feedback on courses is locked up in the department offices and is not allowed to leave the offices (since it is needed for the faculty merit reviews every 3 years), I have not tried reading the comments for the past few years,  despite the value I place on the feedback.  I find the department offices a stressful place, and cannot relax there enough to absorb the feedback. I need to be at home, in a comfortable chair, perhaps with a glass of wine, to be in a receptive enough state to get any benefit from the student feedback.  I wonder whether the switch the campus is making to on-line student feedback will make the feedback more or less accessible than it is now.  Based on the terrible interfaces for student record-keeping system, I fear things will be even worse than they are now.

Because I have not been reading the student feedback as diligently as I did earlier in my career, the quotes from the student comments that were included in the most recent departmental letter for my merit review were nice to read.  They may have been cherry-picked, but not too extremely (departmental letters that are not consistent with the record cause the department to lose all credibility, and I know that people do often check the student evaluations to make sure that the department is not glossing over any problems).  I was tempted to quote some of the comments in this blog post, but that seemed too much like bragging.  (I’ll brag about my son here and about my students, but I try not to brag about myself.)  The key strengths that were coming out in the comments were a broad range of skills and knowledge, willingness to sit down with students and work with them,  enthusiasm for the material, clear examples, and clear, helpful feedback.  Since these were the parts of teaching that I was trying hardest to do well in, I was pleased to see them come out in the student comments.  I would have been shocked to see praise for my lecture notes (I don’t have any), my organization (I tend to follow whatever concepts come up in class), my board work (despite 30 years of effort and improvement, my handwriting on the board is still often awful), or my exams (I don’t give exams any more). It was good to see that the things I thought I was doing well were being appreciated by the students.  I was also pleased that the students responded favorably to the detailed feedback on their work, even though the feedback was often not as positive as modern educational culture favors.


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