Signals & Systems
Without Control
Signals & Systems Without Control
by Joe Tranquillo, Bucknell University, September 2018.
This article originally appeared in ASEE PRISM, Sept 2018. Reprinted with permission.
Imagine that you are standing at the edge of a massive scrapyard with a group of your friends. You are met by a kind woman who offers to give you a tour. A few meters in, she points at a twisted bit of metal and says, "That's pretty interesting. You might need that later." One of your friends dutifully picks it up. This continues as every so often. She stops, points at a beat-up scrap of wood, paper, or plastic, and someone in your group picks it up.
After about an hour, everyone's arms are loaded with a random collection of stuff. The woman smiles and shows you to an exit. On your way out, you meet an older gentleman who offers to take you on another tour. You shrug, drop everything you were carrying, and follow him back into the scrapyard.
This is what many of our engineering students experience as they move from one class to another, day after day, in their tour of higher education. Professors (me included) often point to old stuff that is valuable to us and ask our students to mentally pick it up and carry it with them. But do we really know what will be valuable in their 40+ year careers?
About a decade ago, I realized that my junior-level biomedical signals and systems class was more or less a tour of the scrapyard. Students would play with an equation, write a bit of computer code, or tinker with a device that they probably would never need again. Did this stuff that I loved look like junk to them? I suspected it did, so I tried an experiment.
I brought the Bucknell Improvisation Intensive Ensemble, a performance art group composed of musicians, dancers, poets, and visual artists into my class. I challenged the performers and engineers to co-create biomusical instruments.
- The engineers would need to record biological signals and transform them into music in real-time.
- The performers would need to learn how to play the instruments.
- The engineers got a good dose of music theory.
- The musicians had a first-hand encounter with the engineering design process.
The two groups found that their disciplines were not as different as they thought - both were the application of the theories underlying their respective fields.
"A mantra of the group was to have the brain of an engineer, the heart of a humanist, and the soul of an artist."
Early on it became apparent that I would need to adjust the course schedule to answer questions that were arising in the project. Rather than introduce the Fourier Transform and signal processing later in the semester as I had planned, I introduced these topics much earlier. This reorganization was driven by the curiosity of the students and needs of the project instead of the usual order of topics in signals and systems textbooks. I still covered all of my learning objectives. I simply waited until they became relevant to the project.
As a result, there was a natural push and pull between the theory and project.
About halfway through the semester, the students asked if our class could host a performance. We went all out - we performed in the basement of the student center on Trustee weekend. What was even more striking was that the week before the performance, my engineering students asked if they could be performers. I couldn't have been prouder than to watch my students blend right into the performance.
Afterward one student commented, “This is one of the strangest things I have ever done. I will never forget it. I learned a ton. It became the subject of my medical school interview." (By the way, the Trustees loved it!)
I made a promise to that first group of students that I would never repeat that particular project again. I was worried about the promise at first. But my signals and systems class has gone on to explore interactive fashion (a combination of wearables, fashion, and smart clothing), military technologies, kids' toys and games, and pet technologies. This past year, the challenge was to imagine college classroom technology 30-40 years from now. This year the topic will be travel.
Over time, my expectations have risen, especially in my students' ability to direct their own learning. Educational technology has certainly changed - Arduinos and Raspberry Pies, printed circuit boards, custom 3D printed boxes, and fancy touchscreen user interfaces. But many things have remained the same including the discovery by students that they can create real value, concrete examples of how theory can in fact be useful, and powerful stories students can tell to friends, parents, and interviewers.
Over the years, I have collected a wide range of stories that have touched my heart.
One student asked how an 'a' on a Mac and PC keyboard could be mapped the same way in a program. I had never encountered a student who was curious about a standard before. We looked it up together (ISO/IEC 995) and he presented the idea and standard to the class. In my third year, I noticed that archetypes were forming on the teams, the architect, the builder, the coder, and so on. A group of coders on separate teams started to meet weekly to share insights. Other groups followed suit, and in following years, I hinted that such expert groups might be helpful, and students responded.
You are likely thinking that this can't all be rosy. And you would be right. Some of my colleagues worried that students wouldn't be prepared for the next class, industry, or graduate school. There is no doubt that my students will struggle to compute a Fast Fourier Transform by hand.
However, they will know when the FFT will be helpful in a real situation and can find the code when they need it. How many industry engineers actually use the FFT butterfly method?
Most students enjoy the class, but there are a few every year who do not. Usually those focused on acing tests will complain that my class is unfair. To the majority, however, this approach is an inclusive pedagogy in that it levels the playing field. A few students every year approach me quietly toward the end of the semester. They say that this is the first time they really felt like an engineer.
"One student in particular came to my office smiling and crying. For two years she thought she made a mistake majoring in engineering, but now realized that her inner engineer had been unleashed."
From my perspective, things seemed to be going well, which made me suspicious. Was this approach really working?
I hadn't abandoned all elements of those early days. I would still lecture, give quizzes, and tests. So I was able to compare data from three years before and after I switched to a project:
- The test scores had gone up.
- The ABET assessment had stayed the same.
Faculty agreed that students were more confident in their abilities to navigate the open ended and client/customer-driven senior capstone. They were a bit less risk-averse and more action-oriented. They were also able to translate their hands-on experiences to a more formal design process. Experience really is the best instructor.
I am not a sage on the stage or a guide on the side.
In changing the project every year, I become a co-learner and co-author with my students. That I know the core material doesn't mean that I can answer all of their questions. Students can tell the difference between a professor who is not answering questions "for your own good" and one who genuinely doesn't know the answer but is curious to find out more with them.
Over the years, I read plenty of research-based best practices and pedagogical articles. This was my own scrapyard - picking up pedagogical concepts that might be helpful, while ignoring others. Just like my students, I form my own opinions and teaching voice. I found that what I'm doing isn't all that strange in the humanities and social sciences. They have experimented with democratic classrooms where students take ownership over almost all aspects of the class from topics, timing, and evaluation metrics. I have not gone quite this far, but I found that I have been unleashed as a teacher.
Now on the first day of class, I meet my students at the entrance to the scrapyard. I promise that they can pick up their own parts and determine for themselves what might be interesting. I do my best to help them make some sense of what they find. I may claim something is important and I expect that they will ask why. I should have a good answer.
The class will have a theme, but that is less important than learning how to walk into a scrapyard as a curious observer. I expect students to actively look for connections within engineering and across other disciplines. And that they can be empowered with an entrepreneurial mindset to use their superpowers as engineers to seize opportunities, maximize impact, and create value for others.
We should all leave the scrapyard with stories that are uniquely our own.
Associated Content
Product Archaeology Canvas for Intrapreneurs
Guided Reflection In & Out of the Classroom
Bucknell University - Empowering Students with Authentic Projects
Meet the Author
Joe Tranquillo, Professor of Biomedical Engineering, Director of Teaching and Learning Center, Bucknell University
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