Gas station without pumps

2015 April 27

Ideas for improving hysteresis lab

Filed under: Circuits course — gasstationwithoutpumps @ 08:38
Tags: , , , , ,

The hysteresis lab was the least successful one so far this year.  Students got the designs done and built, but they learned less than they could have from the lab (too much copying of “answers” without understanding) and the lab took too long for the time allotted.

I’m considering going back to a 2-day hysteresis lab, but expanding the lab slightly to include using an nFET to control a loudspeaker (probably with a series resistor to limit current to 500mA). Adding the nFET as a low-side switch would be a useful thing for them to know about (it is a standard arrangement for controlling heating elements, solenoids, and other devices in lab equipment), and would prepare them better for the class-D power-amp lab.

The problem here is that a good oscillation frequency for a touch sensor uses a small capacitor (hence a high frequency), while a good oscillation frequency for the loudspeaker is much lower (200Hz–4kHz).  I can have them add an external capacitor (resulting in little or no touch sensitivity) when driving the loudspeaker, or I can have them build two oscillators: a high-frequency one and a low-frequency one.

I’d want to redesign the board they solder the hysteresis oscillator on to make room for the nFET and loudspeaker connections,  plus giving them more holes for connecting up unused pins on the 74HC14N chip.  This will probably make the board bigger than 2.5cm×5cm, raising the price by 50¢.  They’d need an extra nFET in their kits (another 40¢) and perhaps another screw terminal (80¢).  An extra buck or two for the parts is no big deal, as the lab fee is already larger than what the students are getting, though the extra cost for having to use UC-approved vendors may be eating up most of the “excess” fees.

The lab could be split between the breadboard and the soldering phases, with students who are behind still completing the breadboarding in the second lab.

One question I’ve not resolved is how to reschedule the labs so that there is room for a 2-day hysteresis lab.  Is there any lab that currently takes 2 days that can be squished to 1 day (with less damage than squishing the hysteresis lab)?  How do I keep the reports on schedule so that I can grade over the weekend?

2015 April 24

Email exchanges with the electronics class

Filed under: Circuits course — gasstationwithoutpumps @ 08:35
Tags: , , ,
On Thu, Apr 23, 2015 at 11:07 PM, a student wrote:

The lab report being due Friday, the day after lab, makes it hard to write a good lab report to which I feel I understand the material well, and I know many other students that feel the same way.  The labs this week were confusing and the material was hard to grasp, especially with the last minute changes to the textbook and late lecture material.Most of the students were in lab an hour and half after the lab period, trying to grasp the key points of the material we learned this week. I think writing a report due the next day will cause us to brush over key concepts of the labs and write only on the material we were comfortable with. I know every week,  my classmates and I stay up all night to complete reports without truly understanding the material. As much as you would like us to write the majority of the report before the lab, the concepts start “clicking” when we are in the lab, we can reflect on why we did each part of the lab and how it relates to the theory of the course material. Please consider extending the due date of the final reports to the next Monday with pre-labs.  
​My e-mail response to the class:
The due date of the lab reports is something I spent a lot of time thinking about.  The two reasonable due dates are Friday and Monday after the Thursday lab.  (I also considered a Friday due date for Thursday-Tuesday lab pair.)
In previous years I used the Monday due date, with the expectation that this would give students lots of time to do the writing.  The results were not as good as I would have hoped.  The writing did not show that much a lot of time had been taken over the weekend, and students didn’t start reading the next lab until Monday night, coming into the Tuesday labs completely unprepared.  Lab steps that should have taken 20 minutes were taking 2 hours, because students were trying to to the reading and preparation in lab.
This year I decided to try the Friday deadline, expecting some drop in the quality of the writing, but an improvement in the efficiency of lab time.
The results (so far) have been that the lab time has been used much more efficiently (I still need to work on the design of the hysteresis oscillator lab, which was reduced from about 8 hours last year to about 4–5 hours this year, but needs to get down to 3 hours).  And the reports are not noticeably worse than previous years.  In short, the Friday deadline seems to be working better than the Monday deadline did, so I’m reluctant to change something that is working to something that had not worked.
The only suggestion I have for reducing the amount of time spent Thursday night is to take more time on the weekend creating schematics and writing the structure of the report (what you expect to do, with placeholders for the data).  This advance preparation will increase lab efficiency, reveal difficulties which you can ask about in class before lab, and make the writing not be a last-minute effort.  It is also a good general practice for writing journal papers, design reports, and other documents—do as much of the writing as possible near the beginning of a project, rather than leaving it as a “cleanup” activity at the end.
On Fri, Apr 24, 2015 at 12:14 AM, a student wrote:

I was wondering what you meant with this question for Lab Day 1:

What is the largest peak-to-peak square wave that you can apply to your loudspeaker without exceeding the RMS power limit? 
I feel like we need to have values from an oscilloscope to find the peak-to-peak square wave or am I thinking of this wrong?
​My e-mail response to the class:
The RMS power limit is a specification on the spec sheet (either 10W for the old oval speakers or 15W for the new round speakers).  The question is at what voltage you will dissipate that much power in the loudspeaker.
Some key concepts that we did not have time for yet in class:

  • RMS power is root-mean-square power.  Take the power as a function of time, square it​ (or, more correctly, square its magnitude), average that over time, and then take the square root of the mean.
  • Instantaneous power is voltage times current.
  • For this exercise, I meant for you to use only the approximation that the loudspeaker is a resistor (which is ok if you are at a frequency that puts you near the baseline of your plot).
I just realized that the section at the end of the loudspeaker chapter about power was not completed.

Because neither the book nor the lecture has covered RMS power yet, don’t worry about those questions—I don’t expect you to pick up those concepts with neither textbook nor lecture support.
I think part of the problem was that the loudspeaker lab was later in the quarter last year (week 5), so we’d had a little more time before it, and I’d covered RMS and power by then.  Also we’ve been spending more time on gnuplot and fitting—the class is doing much better on that aspect of the course this year.  I apologize for the mismatch between the material presented and the questions, and have made a note to try to fix the book over the summer to address the problem.

Every class is an experiment in pedagogy—some things work and some things don’t.  I try to learn from each mistake (and each success), so that courses get better each time. I think that this year’s applied electronics class is working better than previous ones, but there are still rough spots to smooth out.  This week is one of those rough spots—packing the loudspeaker lab and the hysteresis lab into the same week is tight (though it worked out better than last year’s schedule, where there was more time for the hysteresis lab, but students took far longer to complete it).

2015 January 6

New quarter, lots of work

Filed under: Uncategorized — gasstationwithoutpumps @ 21:21
Tags: , , , ,

The Winter quarter started yesterday, and my schedule is going to be even fuller than I thought.

I only have two classes this quarter, both 2-unit courses. One course is the freshman design seminar, the other is the senior thesis writing course, so I’m getting students at both the beginning and the end of their undergraduate experience. Two 2-unit courses sounds like a pretty light load, but the courses are more work for me than most 2-unit courses.

For the freshman design seminar, I’m having to create content as I go—we have some lab access this year that we didn’t have last year, and I want to get the students building stuff as soon as I can. But that means my having to build the stuff, to make sure it is feasible, and to figure out how to digest it down to the point where students can have success in the design and construction. I’ll probably be spending more time on the course than any of the students—they’re supposed to have 3.5 hours a week in class or lab and 2.5 hours a week on their homework—I’m expecting to spend more than that prepping for class, and even more on grading.

At the end of last quarter, I filled out a form on the library web site asking for an information session for the course, and I filled it out again yesterday.  Usually the librarians are pretty good about responding to the requests, and I was wondering why I hadn’t heard from them, so I sent e-mail to a couple of the librarians I’d worked with in the past—it seems that the forms on their web page weren’t entering the data into the request system (reason still not known), and they’d never gotten my requests to schedule the information session.  They forwarded my request on to other librarians (a different team handles lower-division information sessions, which worries me a bit, because I don’t want the sort of pablum they usually give freshmen—the ones I’m used to working with know that I want solid training on search techniques), but I’ve not heard back from that team yet. It’s a good thing that I haven’t figured out my schedule for the quarter yet, as I’ve no idea when they’ll be available.

I’m also still waiting to hear back from the engineering lab staff about what training the students need to be able to use the tools in the fab lab, and how I can get access.  I probably need to go and talk with them in person—I’ve gotten no responses to my e-mail requests.

Today I asked the bioengineering undergrads (by e-mail) for volunteers to lead lab tours of the labs they work in, and to explain to the freshmen how they managed to join the lab. My explanation of how to join labs never seems as convincing to the freshmen as hearing directly from juniors and seniors that are in labs. The lab tours are always rather cool, because there is a lot of interesting research going on by bioengineering undergrads here. So far, I’ve had one faculty member tell me he’s assigned some students to do the tour of his lab, but they haven’t contacted me to schedule it yet. Tomorrow, I may ask the seniors doing thesis research if any of them have time to help out.

The senior writing class meets for 3.5 hours this week, but for the rest of the quarter we’ll be meeting only 1.75 hours a week (Wednesdays 5–6:45) as a group, mainly to go over common problems and for them to practice presentations with an audience. I was expecting about 12 students in the class, but I have 19, six of whom had not taken the prerequisite tech-writing course. This pisses me off a bit, since I don’t have time in a 2-unit course to teach everything that should be covered in the 5-unit writing course. But the fault is not entirely theirs—the tech-writing class has been full with students not able to get in every quarter for the past few years.

I had to do some last-minute restructuring of the thesis-writing class because of the size.  The last time I’d taught the class (2 years ago), I read each student’s draft thesis 5 times, providing four rounds of detailed feedback before the final draft was evaluated. I won’t be able to do that this year. Instead, I’ve broken the class into three groups, who turn in their papers out of phase (6 this week, 7 next week, 6 the week after, then repeat).  This plan results in only 3 rounds of feedback before the final version, not 4, but still has me reading a thesis (50-to-100 pages) every day.

I will be meeting with each thesis writer individually for 20 minutes a week, for them to practice their elevator talk, to discuss their research with me, and to discuss their writing.  In some cases in the past, I could not understand their projects from their writing, and it took several rounds of discussion before I realized what they were trying to do, so that I could help them word it comprehensibly.  (In at least one case, the student had misunderstood the statistics so badly that what they were claiming as exciting results were all indistinguishable from chance.) Nineteen students at 20 minutes each is another 6.3 contact hours.

Another difference from the last time I taught the course is that most of the students are in the second quarter of the three-quarter thesis project, rather than in the last quarter. This was a deliberate rescheduling on my part, because I was appalled at how many students had been working for over 20 weeks and written absolutely nothing.  In some cases they hadn’t even properly done their background research, and found that they’d wasted most of the 20 weeks on rather useless stuff that didn’t address their real research questions.  (I did send some politely worded e-mail messages to the faculty who had been “supervising” them, though I wanted to scream at them for their incompetence as advisers.)  Since then, I’ve also gotten much more careful when signing the independent study forms as the undergraduate director and program chair (the forms call for both signatures, but for the bioengineering program, both signatures are mine) to make sure that the students are writing something every quarter.

In any case, the student will not have finished theses at the end of the writing course, but almost-finished ones, with just a few results to fill in next quarter and a little discussion.

So for the two small classes this quarter, I have 11.6 contact hours, 12 hours of grading, and probably 4–5 hours of prep work each week.  I also have 2 hours a week scheduled for office hours, 1.5 for meetings with the department manager, and 2 hours for the department research seminar. So I’m up to 17 hours a week of scheduled meetings and 12 hours of grading—and that doesn’t count the 2–3 hours a week I’ll need to spend with grad students and 1–2 with the nanopore research group, nor the extra advising load that will happen this quarter as all the sophomores try to declare their majors.. So figure at least 22 hours scheduled and 12 hours grading, before we get to my administrative duties.

Today was spent almost entirely on administrative duties—both the department and the bioengineering program are having to do self studies this year for WASC accreditation next year, and I’m stuck writing the whole self study for the bioengineering program and the undergrad portion for the department. I had written a draft of the bioengineering self study over the two-week break while campus was closed, but I only found the form with the prompts for the self study today.  None of what I wrote was wasted, but they wanted a whole lot more bureaucratic bullshit about “Program Learning Outcomes”, a top-down management approach that ensures that every faculty member will run screaming when asked to do anything about the curriculum.  (Actually, our faculty are much more subtle than that—they just nod their heads and disappear.)

I was particularly annoyed by the loaded question in one prompt:

Overall, how has program assessment (including all steps: defining the program learning outcomes, developing the curriculum matrix or rubrics, interpreting the findings) been used to guide improvement of the program? Provide at least one example since the last review of an improvement made to some aspect of the program’s curriculum or course effectiveness.

My current draft answer (which I’m afraid will have to be toned down a bit) is

This prompt assumes that the Program Learning Outcome process has some beneficial effect on improving the program, for which there is no empirical evidence in the bioengineering program.  The improvements in the program have come despite the time wasted on the PLO process, not because of it. The extensive curricular changes described in Section 2 considered data from senior exit interviews, careful thought about what concentrations were uniquely offerable at UCSC, what made pedagogic sense, and what courses and resources were available.  The overly bureaucratic PLO process, particular the curriculum matrix and “rubrics”, took time away from thinking about and discussing the curriculum and pedagogy, diverting it to satisfying arbitrary bureaucratic requirements.

As you might gather, I’m pretty pissed about the PLO process, which calls for an annual report on assessment of one of the Program Learning Outcomes.  I had to make up the outcomes myself last year (none of the faculty were interested), and I’ll have to do all the “assessment” and writing of the report this year for two programs (none of the other faculty are interested). If the process served to trigger discussion about curriculum or pedagogy among the faculty, it might be worthwhile, but it has had the opposite effect, making faculty even less willing than usual to engage in discussions of the curriculum. So I’m stuck writing bullshit reports for administrators who’ll probably never read them, when I’d much rather be teaching, advising students, or fixing problems in the curriculum with other faculty.  (Or even, gasp, doing some research!)

Note: there have been some substantial improvements to the curriculum since the last review—I spent countless hours last year meeting with other faculty (one-on-one or in small groups) to completely overhaul the bioengineering curriculum.  I’m pretty pleased with the result (and students who’ve compared the old and the new curriculum wish that I’d overhauled it a couple years earlier, so that they could have done the new curriculum). But it really was the case that the “Program Learning Outcomes” was a distraction and a sideshow that cut into the time I had to think about and fix the curriculum.

Anyway, after meeting with the BME chair and department manager this morning, to set the agenda for this Friday’s monthly BME faculty meeting, I spent most of the rest of the day trying to wrestle the draft of the bioengineering self-study into shape so that I could share it with the bioengineering faculty, while answering the loaded questions of the administrators. (I’d shared the first draft and gotten feedback from only two faculty out of the thirty—both of them instructors, not tenure-track faculty—two of the best teachers in the School of Engineering.)  I’m unlikely to get much out of the rest of the faculty—I have no carrot or stick to encourage compliance (the program chair of the bioengineering program comes with 0 resources, not even a course buyout for hundreds of hours of work on the curriculum and the self-study).

I had been planning to spend the afternoon doing a first draft of the undergraduate self-study for the bioinformatics program, but the amount of extra work needed on the bioengineering one took up my whole afternoon. I spent a lot of it asking staff for the data that the administrators wanted—much of the data they asked for was not available and will take the staff several days to try to compile. Some of the prompts were particularly irksome:

Provide a brief description of the learning outcomes assessment process, including a multiyear assessment plan, references to assessment instruments provided in Appendix III (e.g., a capstone rubric), and a summary of the annual assessment findings regarding each of the program learning outcomes (as many as have been
assessed to date). Comment on what the indirect evidence from the undergraduate major (UCUES) survey, such as students’ self-reported competency levels and satisfaction with educational experience, indicates in terms of the strengths and weaknesses of  the program. How do measures of direct evidence of student learning agree with indirect measures?                           

What is the UCUES survey data I’m supposed to analyze?  Well, after trawling through my e-mail I found a promise that I’d get the data in December. I never did, so I asked. Oh, they might have that by next week, maybe.  So much for trying to get the self-study written before the thesis-a-day grading starts tomorrow!  The “assessment instruments in Appendix III?” There aren’t any—I only wrote the bloody outcomes last year under duress, and there haven’t been any “assessment instruments” (by which they probably mean bullshit surveys and meaningless statistical analysis of portfolios using made-up “rubrics”). So, summary of annual assessment findings: “there haven’t been any and they wouldn’t mean squat even if there were some”.

I do have several years’ worth of portfolios from graduating seniors as well as notes from exit interviews (both portfolios and exit interviews are requirements for graduation), and I’ve actually read a lot of the student theses in depth. That’s useful to do, and a lot of the ideas for the curriculum overhaul came from discussing the curriculum with graduating seniors at the exit interviews, but turning the portfolios and interviews into an “assessment instrument” using their 50-page guide to the process?—pure, unadulterated educrap.

 

2014 June 12

Starting on book for circuits lab—scheduling labs

Filed under: Circuits course — gasstationwithoutpumps @ 23:59
Tags: , , , , ,

In Revised plan for circuits labs I provided a tentative schedule for the applied circuits course and lab, which I ended up not really following (dropping the FET measurements, moving the sampling lab after the loudspeaker lab, and swapping the order of the pressure sensor and the class-D amplifier).

I’m now trying to turn the course lab handouts into a book (which means adding everything that was previously just in lectures), and I’m trying to rearrange the lab schedule to fit better into the 10-week quarter and to flow a little better pedagogically.

In this post, I’ll ignore the lecture component, but just look at a possible reordering of the labs.  Squeezing the KL25Z soldering and both halves of the thermistor lab was too much, and the sampling and aliasing lab did not work well late in the quarter, so I’ll strip the filter design out of the sampling lab and simplify it a bit to get it in the first week, and move the thermistor lab fully to the second week.  I’ll have to squeeze somewhere else, and I think that the best bet is the hysteresis lab, which took far longer than it should have.  I still want to have data-analysis Wednesdays, and reports due on Fridays.

Tuesday week 1 Unpacking parts, labeling capacitor bags, using wire strippers, making clip leads, Soldering headers onto KL25Z boards, downloading data logger to KL25Z.See soldering instructions at Soldering headers on a Freedom board and Jameco soldering tips
Thursday week 1 Sampling and aliasing lab (no filter design)
Tuesday week 2 Measuring input resistance of multimeter, and of oscilloscope.
measuring thermistor resistance at many temperatures.
Thursday week 2 Measuring voltage of thermistor voltage divider, recording voltage vs. time.
Tuesday week 3 Measure I-vs-V DC characteristic of resistor and of electret mic, both with multimeter and with KL25Z board.
Thursday week 3 Look at mic with resistor load on oscilloscope (AC & DC coupling).  Filter design for AC coupling. Loudspeaker on function generator?
Tuesday week 4 Characterizing impedance of loudspeaker vs. frequency
Thursday week 4 Characterize hysteresis in Schmitt trigger chip using data logger. Breadboard hysteresis oscillator with various R and C values, measuring frequency or period (oscilloscope or frequency meter?).
Make and test touch sensor with breadboard oscillator. Solder hysteresis oscillator. Estimate capacitance of touch from change in period of hysteresis oscillator.
Tuesday week 5 Impedance of stainless steel (polarizing) electrodes in different NaCl concentrations (at several frequencies).
Thursday week 5 Impedance of Ag/AgCl (non-polarizing) electrodes in different NaCl concentrations (at several frequencies)
Tuesday week 6 Low-power single-stage audio amplifier with op amp
Thursday week 6 catchup day? characterizing photodiode or phototransistor?
Tuesday week 7 Pressure sensor day 1: design and soldering instrumentation amp prototype board
Thursday week 7 Pressure sensor day 2: further debugging.
Recording pressure pulses from blood-pressure cuff.
Tuesday week 8 Photodiode or phototransistor with single-stage simple transimpedance amplifier.
Freeform soldering to attach leads for fingertip transmission sensor.
Cut-and-try design for transimpedance gain needed to see reasonable signal without saturating amplifier. (Determine AC and DC components of current)
Thursday week 8 Fingertip pulse sensor with 2-stage amplifier and bandpass filtering.
Tuesday week 9 class D audio amplifier day 1(preamp and comparators) (problem with Memorial Day on Monday?)
Thursday week 9 class D audio amplifier day 2 (output stage)
Tuesday week 10 EKG day 1:  breadboard and debugging (confident students could go directly to soldering)
Thursday week 10 EKG day 2: soldering, debugging, and demo.  Last day for any catchup labs.

I’m not really comfortable with the class-D amplifier in the week with Memorial Day. I’ll have to double check when Memorial Day comes next year.

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.

Next Page »

%d bloggers like this: