Welcome to My Blog!

This blog highlights the work that I did during my graduate studies as part of a partnership between the University of Michigan College of Engineering and the Ypsilanti Public School District from January 2008 through April 2011.  During the first two and a half years (Jan 2008 - May 2010) I assisted high school math classes by introducing engineering concepts and applications to the students, which involved weekly interactions with students in four separate classes.  In the final year (September 2010 - April 2011) I was involved in middle school science classes, planning and facilitating laboratory activities on earth science topics.

I hope you enjoy my reflections from my time at Ypsilanti High School and Ypsilanti Middle School, which you'll find in the earlier entries of this blog.  If you have any comments or questions for me, please don't hesitate to contact me!  You can find more information about me as well as contact information at my personal website: www.stevenhoffenson.com.

Water Filters

During the last two weeks, we did a lab where the students designed and built water filters. To me, this lab seemed much more successful than the earthquake lab, and I usually left the school at the end of the day feeling good about what we did. This lab was designed to take less time than the previous one, and the students' tasks were simpler than in the earthquake lab (thanks to experience and some tips from Lucie Howell). I also completely cut out the powerpoint, which I think was a good move with this age group. This was again a two-day lab, and I spend Monday and Tuesday of last week with Mrs. Buckwalter's classes and Monday of Tuesday of this week with Mrs. Karalash's classes.

Day 1 began with me starting a discussion with the class about drinking water. I asked "who drinks water?" and usually everyone raised their hands, so I followed it up with "where does that water come from?" I got a variety of answers to this question (which was what I was hoping), with answers ranging from "the ocean", "the lake", "wells", "rain", "the faucet", and "the Ypsilanti Community Utilities Authority." Regardless of this, I tried to get it all back to the fact that our water in Michigan typically comes from the Great Lakes, which are the largest source of fresh water in the world. I then transitioned the conversation toward the water cycle (precipitation, evaporation, condensation), which I drew on the board. We talked about how nature cleans water through evaporation and how the dirtiest part of the water cycle (runoff and rivers/lakes) is where we get our water, which means we need a good way to clean water.

Usually around this point I would pass out the Day 1 worksheets, which had 3 questions on them that we answered together and space for two drawings of filter designs. We then passed out the materials, which were a two-liter bottle with the bottom cut off, gravel, sand, cotton balls, rubber bands, cheesecloth, coffee filters, and masking tape. In Mrs. Buckwalter's classes we didn't have the sand, and in Mrs. Karalash's classes we didn't have rubber bands. The students were asked to draw and label two different ideas for filter designs, and then as a team of 3-4 students pick one and build it. I passed out some dirty water (manufactured with water and potting soil) for the students to experiment with for the rest of the hour (usually around 15-20 minutes), and at the end of the hour they packed up their materials and put them away for Day 2.

Day 2 started out with the students retrieving their materials and having about 15 minutes to rebuild their best design and make a detailed drawing of that design. Once the students were ready, we tested the filters, and one at a time the teams came up, explained their designs, and I poured dirty water in and we watched the cleaner water come out. At the end, all of the cups of "clean" water were lined up, and we decided who had the cleanest water. If there was a tie, we went with the team that had the most water won (since they all had thirty seconds with the exact same amount of water). We congratulated the winning team, and we talked a little bit about what seemed to work about their filter. Mrs. Buckwalter asked her classes to vote on which material they thought was the best filtering device, which I thought was a nice idea, but must've forgotten for Mrs. Karalash's classes. We then had the students clean up their filters, throwing everything away except for the bottles, which they cleaned up for me for later use. When there was time at the end, we showed the students some videos. Mrs. Buckwalter had found a video about the Central African Republic that highlighted some of the problems with water shortages and their health impacts in that country. In Mrs. Karalash's classes, I brought in a couple of videos about engineering solutions to help regions with water shortages, one of which was from U of M (the Wheelo) and the other from a competition called "Innovate or Die" (the Aquaduct). The students were surprisingly engaged in watching these, and I was really happy with that.

Overall, I think this was a successful activity for the seventh grade students. It was simple, we didn't bore them too much, and they got a chance to build and experiment on their own. The competition didn't really have any real prize (we gave the winners a certificate), but the students still wanted to win. Naturally, there were always a few students who didn't seem to care or who disagreed with their teams, and there were several students who would wander around the room and see what other teams were doing; surprisingly, most of these side conversations were still about the project, which I thought was great. I would recommend this lab activity for this age group in the future.

Earthquake!

For the last two weeks, I got to do my first lab in the seventh grade science classes. Last week I went in on Wednesday and Thursday for Mrs. Karalash's classes, and this week I was in Mrs. Buckwalter's classes on Tuesday and Thursday (Wednesday was a field trip day). The lab was about designing and building earthquake-proof buildings, which is an activity that has many different versions all over the internet. None of these versions seemed to fit our purpose well, so I created my own version of a two-day lab, where Day 1 was about brainstorming and designing and Day 2 was about building and testing.

I started Day 1 with a three-part powerpoint-based discussion that was only supposed to take up 15-20 minutes before leaving the students with 25-30 minutes for brainstorming, designing, and selection of a final design. The first part of the discussion was about engineering design, which began as 12 slides in Mrs. Karalash's first class and ended as 3 slides in Mrs. Buckwalter's classes. The point of this was to introduce the students to the engineering design process, using a lot of the slides that I presented to some high-schoolers a few weeks ago on campus. This seemed to be way too much, as the students' attention waned very quickly (prompting the gradual removal of 75% of the slides). The second part of the discussion was on earthquakes in general, and I showed a news clip video that talked about a company that retrofits buildings for earthquake-resistance. I followed this up by discussing some ways (from their textbooks) that buildings can be designed to minimize earthquake damage. We also used this time to answer the pre-lab questions that were on their worksheets: What happens during an earthquake? Can we predict where and when they will occur? What dangers do earthquakes pose to people? How can we as designers and engineers prevent some of these dangers? In Mrs. Karalash's class, we answered all of these questions together as a class, and we basically told the students exactly what to write on their worksheets (though some still neglected it); in Mrs. Buckwalter's class, we let the students come up with their own answers (and gave them some time to do so).

The third and final part of the powerpoint introduced the design activity - to redesign the Port-au-Prince (Haiti's capital) City Hall, which was destroyed during the earthquake back in January. In Mrs. Karalash's classes, I explained that the student teams were design firms competing for the contract against the other "firms" in the class, and we listed 4 or 5 design criteria that they will be evaluated on (earthquake-resistance, appearance, functionality, cost/environmental friendliness). This seemed to go over their heads, so in Mrs. Buckwalter's classes I simplified it and just said that their job was to design the new City Hall. From here, I explained that their assignment for the rest of the class was to brainstorm and draw at least 5 different building ideas, and then as a team to agree on one final design to start building the following day. Depending on the class, the students typically had between 10 to 20 minutes for this part, which didn't seem like enough time. We also had to continually remind the students of what they were tasked to do, as they seemed to have a lot of listening problems. The goal was for them to have detailed drawings of what they planned to build so that they could come in the next day and immediately start building. Unfortunately, this didn't happen for the majority of the teams.

Day 2 was all about building and testing, which had varying degrees of success in each class. Before we gave the students materials, we made them finalize their designs on paper ("measure twice, cut once"), and depending on when they did that, they had 10-25 minutes for building. After they finished building, we weighed, measured, presented, and tested the buildings. This went very differently in Mrs. Karalash's classroom than in Mrs. Buckwalter's classes, partly because of the classes themselves and partly because we had a chance to learn from the earlier classes to improve the later class experiences. In Mrs. Karalash's classes, we typically needed 15 minutes or so for the students to finalize their designs before they could get the materials, and then we gave the students 10-20 minutes to build. The students didn't know how to use the scales, so we set up a "height-measuring station" where Mrs. Karalash used a meter-stick to see how high the buildings were. Then they came over to the "weight-measuring station" where I weighed them using the balance scale. After that, the students had a chance to present (and many of them got very shy or had nothing to say) and then we shook it. Unfortunately, about 4 buildings into the first class, the shaker fell apart. There were several problems with it, and I tried to fix it before realizing that I didn't have the materials, which frustrated me through the end of the hour. For the rest of the day, I settled on just holding the motor down by hand and adjusting the rotating arm between each test. Because of this three-stage process of testing, we were always rushing to finish on time, and we never had time for the reflection questions, which was unfortunate. In Mrs. Buckwalater's classes, we let the students weigh and measure their own buildings during the "build" phase. This meant that when we started testing, all we had to do was present (and the students had fewer problems speaking in front of the class) and test it with the shaker. It helped that the shaker had fewer problems, though I still had to find something heavy to weigh down the top of the shaker table and adjust the rotating arm between tests. Still, we were able to get through this stage much more quickly, and we actually had time to let the students answer the reflection questions and turn in their lab worksheets.

There are some more major differences that I noticed between these 7th grade classes and my high school algebra and geometry classes that I worked with for the previous two and a half years. One of them is that the teachers tend to step up and take charge a lot more than in the high school. I was expecting to lead the entire two days by myself, but in both classes the teachers tended to take over and help lead the activity. This was somewhat a relief to me, because I'm not sure if I'd be able to settle down some of these classes by myself. In the high school (at least with the teachers I worked with), the teachers were all too happy to hand over the floor to me, and often took the opportunity to catch up on work, leaving me relatively alone to deal with any distractions and keep the students' attention. The other thing is just the maturity levels of the students, which is much lower than what I saw in my high-school students that were typically 2 years older.

Welcome to Middle School

My first days in the middle school gave me a chance to introduce myself to the students and to get to know them a bit better. Over the course of three days, I visited 8 seventh-grade classes (4 of Mrs. Buckwalter's and 4 of Mrs. Karalash's) and used up between 25 and 40 minutes to discuss myself and the general concepts of engineering. I started out by telling the students a little bit about where I'm from and discussed what I'm doing in their classroom, and then I went into trying to define engineering. After I discussed what engineers do and what kinds of jobs engineers have, we played a little game called "Stump the Engineer." This involved me challenging the students to come up with a product that did not involve an engineer. Some of them came up with good examples (fruits, vegetables, and pets were the best in my opinion), but I was always able to come up with a way that engineers helped us get those products (harvesting, transportation, storage, etc.). I think this was good in showing the students that engineers touch our daily lives in ways that we don't typically think about. We concluded by talking a bit about my research on vehicle safety, and in some classes I was able to talk about the MShoe, which was a project I did to design a shoe that would generate electricity to charge an iPod.

For the most part I thought the talks went well, but I didn't quite anticipate the number of questions that middle school students would ask, and I ended up taking up more time than I had hoped. Both teachers were very supportive of me and were surprisingly okay with me taking up most of the class periods. Similarly to high school, typically 10-20% of the class is active in asking and answering questions, and the other portion of the class only speaks up when I happen upon a special interest of theirs. So, my goal for when we start doing labs should be to take special care to engage those students who don't speak up as much. As I experienced in the high school over the last two and a half years, each class sort of has its own personality, and some are very quiet (making it difficult to ask questions and have interesting conversations) while others are very energetic (making it difficult to settle the students down when an exciting topic comes up).

The biggest difference from high school that I noticed was in the maturity level of the students. When I told the students that it was okay to ask questions throughout the talk, I ended up getting a lot of comments and questions that were totally off topic. I liked the enthusiasm and the way the students were willing to be open with me, but I'd like to see that energy in a more directed manner.

Final days at Ypsi High

I'm not good with goodbyes, so I'll just spit it out: this is my last post of the year. This academic year has had its ups and downs, but I certainly continue to learn a lot about teaching, about high school students, and about engaging non-technical audiences in interesting topics related to technical things. In my last two days I had the opportunity to do a design activity, which was bridge building out of candy (the same activity that I did with the students at the Expo in December), and I had a while to talk about my research on vehicle design optimization. These both went really well, and it was a great way to close out the year in these classes.

Last week I did the bridge building activity in the second and third hour classes. Since it was a short day, fourth and sixth hours didn't exist, so I suppose they missed out. I started with a brief slideshow talking about bridges with examples of good design and bad design, and showing them what a truss (triangular structure) is and why they are stronger than square structures. From here I gave them their task: to design and build a bridge (in teams of 3) using only gum drops and toothpicks which would span 11 inches. Ms. Tran helped them out by telling them that their participation would be graded, and winning any of the four awards would give them extra credit on their progress reports coming out the next day. The class was shorter than the activity was designed for, so we only had about 25-30 minutes to design, build, and test. I gave the students 5 minutes to just plan their designs and sketch them out before I even gave them the materials, and then they had about 15 minutes to build. Particularly in the first class, we were extremely pressed on time, and with less than 5 minutes left it was clear that they wouldn't finish, so I changed it from 11 to 6 inches. It turned out that 6 inches was way too easy! The students' bridges withstood all the pennies (weights) that I brought and even went through most of Ms. Tran's change. They did a nice job though, even though we ran out of time during testing. In third hour we were able to get through everything, this time with 8 inch bridges. For the most part, the students got very into this activity, and the group sizes of 3 were good to make sure everyone was able to contribute. I'd do this again.

Today I wanted to finally talk about my research, since I haven't directly shared it with the students yet. I started out by telling them that when I'm not in their classroom, I'm at U of M working on computers running simulations and analyzing data for my research. I used this opportunity to remind them that as a graduate student I'm getting paid to do this research, so it's sort of like a real job. I started out with some videos of the crash and blast simulations that I've been running, just to give them something interesting to look at and grab their attention. I then introduced the phrase "design optimization" and asked them to define it. I'm still surprised at how few students know the term "optimal" or "optimize", but there was always some student that could give us the gist. I then asked what the "optimal" or "best" car would be? Is it the safest car? most fuel efficient? best looking? least costly? fastest? The students often replied that it should be all five, but I suggested that this isn't the case and cited examples of vehicles that are among the best in certain categories, but seriously lacking in others. Next I explained that in order to evaluate cars on these criteria, we have to be able to quantify each of the objectives, and I gave the example that we quantify fuel efficiency using miles-per-gallon (mpg), but in other places they use gallons per mile or liters per kilometer. Next I actually gave them some time to think about how to quantify the other four objectives, and asked them to talk in pairs about them. Most students seemed to actually spend the minute or two that I gave them to discuss this (which I considered a huge success), and in the end they were able to give some good ideas on how to quantify these things. I explained in the end that this is the most important and perhaps hardest part: formulating problems mathematically with numbers. I then continued to talk broadly about some of my research in both the commercial vehicle sector and military vehicle design, discussing the problems as well as some of the things that I've found in my studies. I closed out and asked if they had any final questions for me.

One of my challenges with this talk was in keeping it simple enough for the students to understand and follow, yet still showing something meaningful. In the end I showed less meaningful things, but brought up some interesting discussion topics that the students were able to participate in. I think the think-pair-share activity was useful in that it gave those who were interested an opportunity to think about the questions I posed, and we got more participation this way than normally. Second hour was very receptive in general, and one of the students asked what he should do if he wants to get into vehicle design for a career - I think he was already interested in this area, but my presence might have strengthened that interest, which I consider a success. Third and fourth hours were slightly less engaged in the latter part of the presentation where I discussed my research, but they were still polite and receptive to me. Sixth hour, as usual, was rowdy but respectful, and many of the students contributed to the discussion and asked questions. All in all, I think this was a great way to close out the year, which lets me leave with a fairly positive attitude toward my students and my contributions at YHS. Thank you to everyone who made this experience possible!

Reduce, Reuse, Recycle

No, this post isn't about environmental friendliness. In the last two weeks I gave presentations that I "recycled" from last year, both of which went pretty well once again. Since I used them both last year and they both went well, I allowed myself to be lazy and only made a few minor changes from the old slides. As a result, I can say that they both went well, though not exceptionally so. As is often the case, many of the students checked out early and quietly ignored me for both talks, but I did feel like there were a good number of students who stayed with me and as a result learned a few things.

Last week's talk was about the angles that are important when steering a car. I started out by showing a video that had a Corvette driving along a curvy road before spinning out because of driving too fast and taking the curve too hard. So I posed the question: why do cars spin out? Most of the answers revolved around poor driving or poor car maintenance, so I pushed them to continue brainstorming and come up with the more specific cause: the tires of the car slip against the surface of the road. So then I asked the students whether the wheels of the car turn at the same angle as the steering wheel, and usually got a resounding "no", which is good. Power steering makes it so that we can turn the steering wheel almost a full turn while the wheels only rotate 20 or 30 degrees. Next I asked whether both front wheels turn at the same angle, and most people thought the answer was yes. I spent the next couple of slides showing them why the tires should turn at different angles - the inside wheel (with respect to the turn) needs to turn a little bit steeper because it's revolving around a tighter turning radius than the outside wheel. We then talked briefly about handling and how at high speeds, the tires of a car slip on the road, and if there is too much weight in the back of the car, that might cause spinning out to occur more easily. This was a fairly quick talk (less than 15 minutes), and I did get the impression that the students were engaged and many of them learned a few things or at least will think a bit differently next time they are in a car.

This week I talked about flight. I started out with a cool, somewhat funny video that showed some early attempts at flying and mostly how some elaborate machines broke down after they started moving. We then talked about some of the reasons that we fly (we can go really fast, avoid obstacles, it's safe, it gives the military more options), and then we went through the three main types of aircraft that we see: blimps, airplanes, and helicopters. With blimps, we fill it with a gas that is lighter than air (I showed a periodic table to illustrate what gases are lighter than air), and heat it up or cool it down to make it lift or lower the weight in the cabin. With airplanes, there are a lot of complex forces going on, but the important force is lift, which is controlled by the speed of the aircraft along with the angle that the wings hit the air. I spent a little bit of time discussing those angles, but tried not to talk too long for fear of losing students. I ended by briefly discussing how helicopters work, and how the speed and the angles of the main rotor affect the lift of the vehicle. I think on the whole it was valuable and I think that some of the students gained some higher understanding of the challenges and current methods in flying work.

Explosives & Scaling

Two weeks ago, I came in with an updated version of my talk on explosives, and I was very pleased with the response I got in all of the classes. I start out with a short video clip that shows two military vehicles driving on a dirt road, and a land mine detonating between the vehicles, which does a great job in grabbing the students' attention. I then pose the question: what if the humvee had been directly above the explosion? What would happen to the vehicle? What would happen to the occupants? The students are actually very good at coming up with responses - usually at first someone says, "the vehicle will explode," but when I push them harder to be more specific they'll say something about the vehicle being thrown into the air and possibly deform. I then pose a question regarding how we would learn about the effects of explosives on vehicles so that we can design safer vehicles, and get them to say something about physical or virtual testing. Everyone agrees that physical tests are expensive, so we talk about scaled-down testing, which is something that I did as an undergrad while at the University of Maryland. This is also something that ties in directly to their current classwork, which is on proportions and ratios. So, I show them how I scaled down my tests, and what the relevant proportions are, and hopefully everyone is able to see how scaling can be useful in real life. At the end, I ask a question about what other professions might use scaling/proportions, and the students were able to respond really well with examples about architects, rollercoaster designers, maps, etc. Second hour (accelerated) went fairly well, though the morning classes are less responsive since it's so early. Third hour (non-accelerated) was also very attentive and respectful, and we went all the way until the bell rang. Fourth hour (non-accelerated and usually my toughest crowd) actually seemed to really like it. The students actually sat through the dismissal bell while I continued talking, which both Ms. Tran and I were extremely impressed with - that may be my most successful moment so far with this group of students.

Today is the day before the students' Chapter 8 test, and so I came in to help the students with their in-class practice tests. I don't have anything eventful to talk about, but I did get a feeling that many of the students are more comfortable with me than they have been, and asking questions of me wasn't so bad. It seemed like there were enough questions to occupy me throughout the three class periods that I was there for, so I consider that a meaningful three-hours' work.