Event Supervisor Review: Circuit Lab
First off, I would like to say that I had a great time meeting many of you competing yesterday. The test and labs were very challenging and Asher and I were very happy to see competitors successfully solve some of the harder problems on the test. I hope that all that competed and those of you that will take the exam in the future will use it as a study resource and a tool to help you discover some important engineering skills as well as some interesting circuit-related concepts and applications!
Over the course of the past several months, Asher, Megan, and I have been working together to write several circuit lab exams for different competitions. Often times, we would find that we wrote a problem or two that we felt were too hard to be appropriate for most competitions. We saved those problems and put them on the MIT exam. The exam that you all took was definitely one of the most challenging exams in terms of time constraint and problem difficulty that I would expect to see this season. There were 1-2 pages too many on that exam and in most cases, I would have stopped earlier: but this exam was for MIT, and we wanted our exam to live up to the reputation. That said, I don't think that any of the problems were a huge stretch from the rules and probably represent the most difficult problems that could be written for each of the topics on the rules.
As always, here is the test and key: MIT 2020 Circuit Lab Test and Key
We spent a lot of time thinking about what an interesting, yet feasible lab would look like. The classic battery and resistor labs with "black box" measurements seemed too boring, as did the "draw a circuit diagram of the battery-resistor circuit". We wanted our labs to be more interesting and representative of what you might see taking a university electrical engineering course. The labs ended up being a "see, then do" type of format with competitors first analyzing a circuit that contains the fundamental aspects on a breadboard (op-amp circuit and logic circuit), drawing the given circuit (simply looking at what was built on a breadboard and drawing a schematic), and then building (or adding on) an additional circuit representing a slightly more advanced concept (Lab 1: Adding a non-inverting op-amp to increase voltage output, Lab 2: OR gate observation, building a 3-input NOR gate). We also wanted to minimize the movement of students without sacrificing the quality of the lab experience. We decided the best option would be to make the labs portable and purchased DC breadboard supplies with 9V battery inputs for circuits to be built on individual breadboards. I was very happy with the way the lab setup worked logistically, and if we had had more volunteers, the resetup time of 10 minutes would have been perfect. In the future, I think I would try to decrease the amount of activities in the lab section while maintaining the weighting. I think it is important for students to have more of an ability to work with real components and not just solve theoretical problems on paper.
Asher and I have worried that teams would excel easily at many components of our exam since we have written and released our past exams. This didnt seem to be the case and despite seeing teams with UT Austin and Boca/NT tryout exams in their binders (which is totally legal btw), we didnt see any teams feeling the need to "refer" to them to help solve problems on the MIT test, which we have striven for and have done our best to avoid repetition (other than in format). A handful of teams found a loophole through Lab 2 that didnt require transistors to build the circuit using transistors as we had intended.
While I was slightly disappointed to not see any teams breaking 200 pts, I wasn't very surprised given the difficulty of the exam and time in the season. While the scores werent as high as I had hoped, the distribution was still pretty good and I think teams were separated fairly well. Stats:
High: 153, Mean: 62, St. Dev: 39