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I’ve had mixed feelings about some engineering curricula designed for the under-12 set. There are an awful lot of lesson plans available on-line that have big ideas (space exploration, zero-gravity adaptation) and big words (ecliptic, aphelion) but when you get right down to it, the students aren’t building space suits or improving solar panels; they’re measuring evaporation in a tin pan (I made this example up to protect the hard-working institutions that also sometimes turn out great materials). Besides the feeling of “bait and switch,” this is also disappointing because it fails to help students or teachers make sense of what engineering is, and why it’s not the same as science.
So I was intrigued to find a link to Engineering is Elementary recommended by Mark Guzdial in response to the post “Teaching Engineering Thinking” at Gas Station Without Pumps. The contexts are smaller (design an alarm circuit, design a bridge) but in those lessons, students are going to design and build and alarm circuit or a bridge. They’re also going to assess their creations and improve them based on the assessment. The language is simple and every lesson’s title start with “Designing a …”, except the ones that start with “Making a …” or “Improving a …”. There’s a table-top mag-lev system in there. I don’t know anything about these products — cost or effectiveness or ease of use. But when some projects for elementary school students make me think “Oh, I want to do that one,” it makes me curious.
If you’ve used them, what are they like? Could I use them with a Brownie troop (6-8 year olds)? Could I use them for my adult students when we need something light as a break? If you try them out, please let me know how it goes.
I just received a notice from the American Society for Engineering Education about a free online PD project for faculty who teach introductory engineering science. It’s called Advancing Engineering Education Through Virtual Communities of Practice, and they’ve just extended the application deadline to Feb. 8. Participants can choose from these topics:
- Electric circuits
- Mass & energy balance
I can’t tell if you have to be a member of an engineering department, or if it’s enough to teach one of these topics; I can’t even tell if you have to be American. In any case, I applied. From what I can tell, accepted applicants participate in once-weekly online meetings with facilitators who have experience with “research-based instructional approaches” (though they don’t tell you which ones, except for references to “Outcome-Based Education” — which I think of as an assessment approach, not exactly an instructional approach).
I suppose I should be concerned about the lack of details on the website (even the application deadline on the front page hasn’t been changed to reflect the extension), but I’m chalking it up to this being the prototype run, and anyway, the price is right. The informed consent form makes it clear that this is a research project to explore the viability of the model, which is fine by me. It’ll be worth it if it leads to any of these things:
- Working on instructional changes in a systematic way (rather than the somewhat haphazard and occasionally accidental way I’ve been doing it so far)
- Focusing on the specific ways particular instructional approaches play out in circuits courses, not to mention deepening my content knowledge
- Having a consistent group to work with over the course of 6 months (and two different academic years).
It seems to bring together the advantages of something like the Global Physics Department, with the bonus that every meeting will be about exactly what I teach, and the meeting time will be a part of my scheduled workday.
The email I received from the ASEE contains details that are not available on the website, so I’m including it below.
NSF-funded project to develop engineering faculty virtual communities of practice
Engineering education research has shown that many research-based instructional approaches improve student learning but these have not diffused widely because faculty members find it difficult to acquire the required knowledge and skills by themselves and then sustain the on-going implementation efforts without continued encouragement and support.
ASEE with a grant from NSF is organizing several web-based faculty communities that will work to develop the group’s understanding of research-based instructional approaches and then support individual members as they implement self-selected new approaches in their classes. Participants should be open to this new technology-based approach and see themselves as innovators in a new approach to professional development and continuous improvement.
The material below and the project website provide more information about these communities and the application process. Questions should be addressed to Rocio Chavela at firstname.lastname@example.org.
If you are interested in learning about effective teaching approaches and working with experienced mentors and collaborating colleagues as you begin using these in your classroom, you are encouraged to apply to this program. If you know of others that may be interested, please share this message with them.
Please consider applying for this program and encouraging potentially interested colleagues to apply. Applications are due by February 8, 2013.
Additional Details About the Program
Faculty groups, which will effectively become virtual communities of practice (VCP) with 20 to 30 members, will meet weekly at a scheduled time using virtual meeting software during the second half of the Spring 2013 Semester and during the entire Fall 2013 Semester. Each group will be led by two individuals that have implemented research-based approaches for improving student learning, have acquired a reputation for innovation and leadership in their course area, and have completed a series of training sessions to prepare them to lead the virtual communities. Since participants will be expected to begin utilizing some of the new approaches with the help and encouragement of the virtual group, they should be committed to teaching a course in the targeted area during the Fall 2013 Semester.
VCP Topics and Meeting Times
This year’s efforts are focusing on the introductory engineering science courses and the list below shows the course areas along with the co-leaders and the scheduled times for each virtual community:
Co-leaders are Lisa Huettel and Kenneth Connor
Meeting time is Thursday at 1:30 – 3:00 p.m. EST starting March 21, 2013 and running until May 16, 2013
Co-leaders are Brian Self and Edward Berger
Meeting time is Thursday at 1:30 – 3:00 p.m. EST starting April 3, 2013 and running until May 16, 2013
Co-leaders are John Chen and Milo Koretsky
Meeting time is Wednesday at 2:00 – 3:30 p.m. EST starting April 3, 2013 and running until May 23, 2013
Mass and Energy Balance
Co-leaders are Lisa Bullard and Richard Zollars
Meeting time is Thursday at 12:30 – 2:00 p.m. EST starting March 21, 2013 and running until May 16, 2013
Interested individuals should complete the on-line application at https://www.research.net/s/asee-vcp_application_form. The application form asks individuals to describe their experience with introductory engineering science courses, to indicate their involvement in education research and development activities, to summarize any classroom experiences where they have tried something different in their classes, and to discuss their reasons for wanting to participate in the VCP.
The applicant’s Department Head or Dean needs to complete an on-line recommendation form to indicate plans for having the applicant teach the selected courses in the Fall 2013 Semester and to briefly discuss why participating in the VCP will be important to the applicant.
Since demonstrating that the VCP approach will benefit relatively inexperienced faculty, applicants do not need a substantial record of involvement in education research and development. For this reason, the applicant’s and the Department Head’s or Dean’s statements about the reasons for participating will be particularly important in selecting participants.
Applications are due by February 8, 2013. The project team will review all applications and select a set of participants that are diverse in their experience, institutional setting, gender, and ethnicity.
I’ve just agreed to be the head judge for a LEGO robot competition for high school students. In light of my workload this year, that probably means I have lost my marbles. However, I couldn’t resist. I judged last year and found it extremely interesting. I’m looking forward to meeting others in the province who love the combination of kids and robots, working with the judges to develop a consistent way to score teams’ performance, and just getting off campus more. Of course, if I ended up recruiting kids into my program, that wouldn’t be so bad either).
Acadia University hosts the local FIRST LEGO League competition for 9-14 year olds, which is co-ordinated internationally. Four years ago, they decided to run an independent high-school competition so that kids who had aged out of FIRST could continue to compete. To see the details, go to the competition page and click on High School Robotics.
My responsibilities are
- defining the challenges (this needs to happen ASAP)
- getting the word out about the competition, which is in February
- answering questions from school teams about the competition and the challenges
- helping with orientation for the judging team
The teams borrow or buy a robot kit and get three challenges to complete — things like moving pop cans, dropping balls into containers, detecting and navigating around obstacles, etc. The teams get two runs through the course, with time in between the runs to make changes to their robots.
How Teams Are Evaluated
- An interview with two judges before their robot runs the course. They have to explain their code, demonstrate their robot, and answer questions about their process
- An interview between the two runs. They have to explain what went well, what didn’t go well, and how they are going to improve.
Things I Noticed Last Year
- The teams tended to be well balanced — either the students were all able to explain each aspect of the robot, or each student was able to explain one aspect in detail. There was the occasional student who didn’t seem to be as involved, but not many.
- The coaches varied widely in their degree of involvement. There were some programs that I was pretty sure the teams wouldn’t have come up with on their own, but they seemed able to explain the logic.
- Almost all the robots performed poorly on the competition field, with many of the planned features not working. This surprised me, since organizers publish the exact dimensions and features of the competition field months in advance. Surely if the design was not meeting the requirements, the students knew that in advance…
- Some teams were able to articulate what exactly was not working after their first run (for example, the robot ran into the wall and then couldn’t turn around), and some teams were not.
- Regardless of their ability to diagnose the problem, most teams were not able to troubleshoot in a logical way. The changes they proposed to improve for their second run often addressed an unrelated component — for example, if their robot had incorrectly identified the difference between white and black cans, they might propose to change the motor speed.
For those of you who’ve participated in robotics or similar competition, any suggestions? I’m especially interested in these questions:
- What helps new teams get involved?
- What features of the challenges can help kids think independently and algorithmically?
- What practices in the design or judging can promote more causal thinking?
The author of Gas Station Without Pumps has posted this thought-provoking list of technician-level skills every engineer should have:
- Reading voltage, current, and resistance with a multimeter.
- Using an oscilloscope to view time-varying signals:
- Matching scope probe to input of scope.
- Adjusting time-base.
- Adjusting voltage scale.
- Using triggering.
- Reading approximate frequency from display.
- Measuring time (either pulse width or time between edges on different channels)
- Using a bench power supply.
- Using a signal generator to generate sine waves and square waves. Hmm, only the salinity conductance meter uses an AC signal so far—I may have to think of some other project-like labs that need the signal generator. Perhaps we should have them do some capacitance measurements with a bridge circuit before building a capacitance touch sensor.
- Using a microprocessor with A/D conversion to record data from sensors.
- Handling ICs without frying them through static electricity.
- Using a breadboard to prototype circuits.
- Soldering through-hole components to a PC board. (I think that surface-mount components are beyond the scope of the class, and freeform soldering without a board is too “arty” for an engineering class.)
I really like this course-design approach, and I think it will yield a very interesting, engaging course.
I started thinking out loud about the kinds of conceptual difficulties I’ve noticed and assessments I use. When I realized it was turning into yet anther one of my marathon comments, I thought I’d open up the conversation over here.
1. Using a Multimeter
When teaching students how to use meters, I’ve found it interesting and conceptually useful for them to use their meters to measure other meters. For example, use the ohmmeter to measure the input resistance of the voltmeter, or use the ammeter to measure the output current of the diode checking function. It gets students thinking about what the meters do, helps them get a sense for the differences between meters (especially if you have a number of makes and models available), and can help them build their judgement about when, for example, a current-sense resistor’s contribution to a series circuit can no longer be ignored.
It makes for useful test questions as well: draw a meter measuring another meter, and have students justify their predictions of what each meter will read.
2. Using an Oscilloscope
The trigger function is difficult for a lot of my students to make sense of. This becomes evident when they make a measurement on channel 1, then make another measurement on channel 1, then infer the phase relationship between two signals that were not measured simultaneously. This also makes a useful test question — describe this scenatio, and ask students to explain specifically why the conclusion is not valid.
I’ll also be curious to know if the students are able to relate the techniques for vector addition to the reality of phase shift in the time domain, including the apparently illogical concept that in a series RC circuit, the resistor’s voltage can lead the supply’s. (Where did the resistor get that voltage before the supply turned on? would be the type of frustrated question my students would be upset about.) Although introducing the concept of start-up transients seems like it should increase cognitive load, I find that my students welcome it as a way to resolve this apparent contradiction. This is easier, of course, if you have storage scopes or (better yet) simulation software.
In case it’s useful to anyone to have an electronic copy of an “oscilloscope grid” (for including in test questions, etc.), here’s one I made. (Whoops, upload problems. Will add it here as soon as the upload succeeds).
When we start making a lot of use of the oscilloscope, that’s when the headaches start to flare up about “what ground is exactly, anyway.” Lots of fruitful discussions are possible; what does the scope’s ground clip mean if the the scope is plugged into an isolation transformer? (Note, some isolation transformers isolate the grounding conductor, others don’t.) What happens when two probes have their ground clips in different places? (This is another favourite test question of mine: what is the voltage across component X, where X is shorted out by scope ground clips).
What does AC coupling do, exactly? Why would you use it — why not just adjust the volts per division? Asking them to measure the magnitude of the ripple on a DC supply can help them make sense of this. My students also often have trouble being confident of the difference between moving the display level on the scope and adding DC offset on the signal generator.
3. Using a Bench Power Supply
This is fairly straightforward, except for current limiting (especially on a supply where the current limit knob is not graduated, or maybe even labelled in any way). I find it useful for students to be able to choose a replacement fuse (and shop for it on a supplier’s website). This apparently simple procedure can help students grapple with the meaning of the distinction between voltage and current. For beginners, it is counter-intuitive to imagine that there is voltage across an open fuse, even though there is no current.
4. Using a Signal Generator
Measuring things in a bridge circuit is another conceptually useful experience; I use it to motivate Thevenin’s theorem, since a bridge circuit has no components in series nor in parallel, making it resistant to simple circuit-solving strategies.
Other uses of a signal generator: if applicable, you could have your students perform a frequency sweep of something. This can yield interesting insights, like noticing that, due to stray capacitance, high-pass filters are actually band-pass filters.
Soldering well, and accurately inspecting soldering, are great skills to have. Surface-mount components might not be out of the question; if you want to introduce them, it’s not much harder to solder a 1206 chip resistor than a through-hole component, and can reasonably be done with a regular iron. Knowing the difference between lead and lead-free solder might be useful too, especially as it relates to reliability and disposability.
I go back and forth about using perf-board. On one hand it’s great for cheap soldering practice. On the other hand, the lack of solder mask makes it very difficult for beginners to make tidy joints, with solder running down the lengths of the traces.
I’ll probably keep using this post as a catalogue of common difficulties. If anyone can think of others (or has suggestions of other technician-level skills that engineers should have), I’d be curious to hear them.
[Update, June 6, 2012: Want to try making play-doh circuits at home? Read the Squishy Circuits official site first!]
I don’t remember who pointed me to this TED talk about making working circuits with play-dough, but I found the idea compelling. When a local Brownie troop called my school and asked if the girls could visit the campus to learn about one of our trades programs, it seemed like a good fit for this activity. I figured I had found an opportunity to do something fun and expose some kids to what’s available at a trades/tech school. I didn’t anticipate that by the end of the evening, 20 kids would be jumping up and down with excitement, proclaiming the incredible coolness of building electronics, refusing to be torn from their creations until they could be demonstrated to volunteers and parents, and vowing to go home and take apart their vacuum cleaners.
Last Tuesday evening, twenty or so girls between 5 and 8 years old arrived at the campus. The “squishy circuits,” as developers from University of St. Thomas call them, were a huge hit. Compared to other electronic projects such as soldering kits or robot-building, this was by comparison inexpensive, easy to set up, and required relatively little technical expertise from the volunteers. Here’s what we did.
Two weeks ahead
Recruited some volunteers. We had one adult for every four kids: some were students in my program, others were Brownie leaders who may or may not have had any background with electricity. Volunteers did things like encourage kids, take pictures, fetch extra supplies, make sure no one got hurt, and occasionally make suggestions of things to try when someone got stuck. We probably could have gotten away with half the number of adults. But I found that the kids really wanted to show us their triumphs — it helped to have a surfeit of “witnesses,” as well as several cameras.
Assembled supplies. For electronic supplies, we ordered from Digikey — they have reasonable prices and they ship overnight. For craft supplies, we hit the dollar store.
The trickiest thing was to find safety glasses that won’t fall off the kids’ faces. An LED can explode into tiny bits of plastic shrapnel if connected directly to a 9V battery, so safety glasses are definitely necessary. I visited a local industrial-supply store and bought a model designed for women. They sold them to me in boxes of 10, and they fit the kids fine. UST has suggestions about what to buy and where to find it, including inexpensive mail-order safety glasses in kids’ sizes.
One week ahead
Made the dough. Recipes are here. I planned one batch of conductive dough and half a batch of insulating dough for every three kids, which was a generous amount. I used a teaspoon of grocery-store-grade food colouring for every batch. The recipe can be multiplied, but it’s very stiff to stir at the end. I was stirring by hand, and a double batch was the most I was physically able to work with. The dough keeps well for over a week if kept at room temperature in a sealed plastic bag.
Gave the volunteers a chance to experiment with the dough, and briefed them about how the workshop would go.
Crimped terminal lugs onto the ends of anything with wires. The helpful folks at UST say that it’s recommended, not required. We didn’t have time to add lugs onto everything, and circuits work without them. But we found that kids who had terminal lugs were able to bring their imagined creations to life, such as Earl the caterpillar, above; kids who didn’t have terminal lugs were able to make lights and buzzers turn on, but got frustrated trying to make it look like the butterfly, elephant, or “spider-cat” they imagined, because the wires kept slipping out of the dough. UST also recommends soldering the lugs; I’m not sure that’s a big advantage, and it significantly increases the skill needed to prepare. I used fork lugs (sometimes called spade lugs or Sta-kons); if you can find the type with a hooked end, it’ll work even better for grabbing on to the dough. The lugs and the tool for attaching (aka crimping) them are available from the automotive section of a hardware store.
Figured out seating and logistics. We had tables of four: three kids and an adult. I didn’t want the supplies on the table when we started, because I needed the undivided attention of the kids while I talked about safety, so I made a bag of supplies for each table but left them at the side of the room: one motor, two batteries, one buzzer, a handful of popsicle sticks, one batch of conductive dough, half a batch of insulating dough, etc.
As people were arriving, they took a seat at a table that had pencils, markers, nametags, and blank paper. We encouraged them to draw the animal (real or imagined) that they would like to make tonight.
15 min: When everyone was seated, I introduced myself and introduced the play-dough. I asked everyone to put on their safety glasses. I demo’ed three circuits: an LED circuit in conductive dough (which I showed with the LED in forward and reverse bias), an LED circuit in non-conductive dough, and a short circuit with an LED. We had a brief conversation about the idea that “electricity has to go through things” in order to make them work.
Safety briefing: there are two rules.
- Batteries must always be connected to dough, not directly to other components.
- Wear your safety glasses.
15 min: First mission: figure out how the components work. I showed them the buzzer, button, and motor, and asked them to hook them up to test them.
45 min: Once kids were getting confident about making lights light up and buzzers buzz, I got their attention and asked them what they wanted to build. Was it an animal whose eyes lit up, or a monster that made noise when you pressed a button? I solicited ideas from each table, mostly so that any kids who were at a loss about what was possible could hear a few different ideas. Then I let them go at it, and circulated with the volunteers.
15 min: When the evening was almost over, we brought the kids together and walked to the electronics shop, where we demonstrated some considerably larger lights and motors, and talked a bit about what it means to do this for a living. Many of them had questions about motors (like in ceiling fans and vacuum cleaners) as well as sensors (like in the drinking fountains we had passed or in auto-flushing toilets), so we talked about that for a bit.
I didn’t really have a good way to end the workshop. I would have liked to spend a little time having them think about what they noticed, or what they might like to build next, but couldn’t really clear up in my head what I was aiming for. So, I thanked them and told them they could take their creations home (except for batteries and motors). We headed back to the activity room, where many of the kids would have happily gone back to making stuff if the arrival of their parents hadn’t interfered.
Total workshop time: 1h 30 min.
The room was, predictably, a wreck. We spent an hour wiping dough off of tables, sweeping it off the floor, etc. Any component that had been in the salt dough had its leads corroded beyond use. The instructions from UST suggest wiping down the component leads with fresh water, which might have been worth it if we had any components that weren’t hideously disfigured. Instead, we just clipped all the terminal lugs off. We’ll crimp new ones on next time.
The other thing I would do next time is get cheap picnic tablecloths from the dollar store, to help contain the mess.
How kids were thinking about electricity
Many kids figured out that any place you connected one LED, you could connect a second one (a parallel circuit). But most had trouble imagining a circuit with more than 2 nodes (a series circuit), and consequently had trouble making their designs a reality. It made me wonder if I should demonstrate both ideas at the beginning.
Consequently, we had a number of kids using the pushbuttons to short out a light. This worked fine and is not dangerous, as long as the battery terminals are connected to dough: the conductive dough has about 10KOhms of resistance in a finger-sized piece.
Many kids had trouble distinguishing the pushbutton from the devices it was supposed to control. For example, one girl wanted her circuit to make noise, and was frustrated that it wasn’t working. She had wired a button into the circuit — apparently visualizing the button itself as the buzzer. It made me wonder if next time, I might not hand out the buttons until the kids had explored the other components.
One student discovered that even the non-conductive dough would allow an LED to light up, if you didn’t use very much of it. She was very excited about this and came over to let me know that I had been mistaken… which naturally I was also very excited about.
Notes for next time
Many of the kids were talking about wanting to continue to experiment at home. I wish I had had some kind of handout or recipe card with more information about electronics for kids, and links like the ones below.
I had two batteries for each table of 3-4 kids. Some kids clearly preferred working together, but others didn’t. In retrospect, it would have been better to have a battery for each child.
Where to Buy
UST has lists of parts available from Radio Shack / The Source / Circuit City (name varies by location, it’s all the same store).
Finally, there’s the Squishy Circuits Store. They sell a kit of components appropriate for one child. More expensive than ordering in bulk from a distributor, but more convenient too — especially if you’re not familiar enough with the components to know what to buy.
- Batteries and holders (such as 9V batteries and terminal snaps, or AA batteries and holders if you want to be able to easily recharge them)
- Small motors: ideally, rated for 3V, less than 30 mA, and the lowest rpm you can find (motors that spin too fast are hard to see). We used a 7V motor rated for 7000 rpm. It didn’t start reliably, and when it did, it was often too fast to see, or would throw off the piece of dough stuck to the shaft.
- Buzzers: buzzers are rated by volume and pitch. Choose lower-pitched buzzers to prevent insanity. We used these 400 Hz buzzers.
- Pushbuttons and/or potentiometers, if desired
- Several colours of conductive dough
- Non-conductive dough
- Extra flour (the dough gets sticky over time)
- Terminal lugs and crimp tool
- Decorating supplies (straws, popsicle sticks, etc. No pipecleaners — the metal rod in the center could short out the battery)
- Lots of LEDs: I had standard 5mm LEDs, but I love the visibility and ease of handling of the giant 10mm LEDs that UST recommends from Evil Mad Science.
- Pencils, markers
- Name tags
- Zip lock bags
- Bucket of soapy water, dishcloths, dishtowels (for cleanup afterwards)
- Table cloths (and floor covering?)
- Info to send them home with participants (i.e. where to get supplies, how to make dough)
If you’re thinking of trying this activity either at home or with a group, and you have any questions at all about choosing components, tools, etc., please don’t hesitate to let me know. It’s quite appropriate for the electronics novice, and I’m happy to help out.
Looking for more kid-friendly science and engineering projects? Try these:
If you teach math or science and are interested in application problems or project-based learning, read on. If you teach other subjects but are interested in what engineering can offer your students, read on too. There are some great organizations and publications in the engineering world that might be of use to K-12 teachers, but sometimes the lack of an “engineering” course in high schools makes it harder to see the link than, say, between high school physics and university physics.
I’m always on the lookout for ways to bridge the gap between those worlds, as well as ways to strengthen understanding of how science and engineering are separate but complementary. In light of that, here’s a bit of info about the American Society for Engineering Education (ASEE), for those who might like to check it out. You don’t have to be an engineer to join, and most of their publications are written for a broad audience (reading level similar to Scientific American, not Nature).
K-12 Working Group and Annual Conference
The ASEE maintains a working group of K-12 educators and higher-ed faculty who develop resource materials and school programs. The group puts on a workshop at the annual conference every year (I haven’t attended, but I hope to check it out). The benefit I’ve found here is mostly meeting the people, not using the lesson plans (I found them a bit simpler than I was looking for) but your mileage may vary.
The ASEE’s monthly magazine, Prism, is a highly readable blend of technology news and educational practice. The current issue’s topics include innovative course designs (Motorsports, Game Development, Engineering Disasters), snake-like robots, assistive technology for disabled athletes, and an article called “Scientist as Mad Artist: An engineering educator merges dissent and avant-garde design.” My students and I regularly use this for project inspiration.
Journal of Engineering Education
This is the ASEE’s peer-reviewed international research journal. I started writing this post today because an article in the latest edition caught my eye: “Problem-based Learning: Influence on Students’ Learning in an Electrical Engineering Course.” Their results included that “participants’ learning gains from PBL were twice their gains from traditional lecture. Even though students learned more from PBL, students thought they learned more from traditional lecture. We discuss these findings and offer implications for faculty interested in implementing PBL.” I was able to access the full text without logging in (let me know if the link doesn’t work). Another interesting title in the table of contents is “Elementary School Students’ Conceptions of Engineering.” Lots of food for thought.
If you check these out, let me know whether they’re useful. I’m interested in your thoughts about what would encourage collaboration between K-12 and higher ed in engineering and technology fields.