Thursday, March 03, 2011

Doing Something "Original" As A Physics Lab TA

Recently, I read a feedback e-mail from a math instructor about a student posting a question in a public forum that was something that he (the math instructor) had formulated himself. He described how it really isn't that easy and it was time consuming to come up with a set of "original" questions to ask the students, so that they don't have the chance to simply copy off some other sources and submit as answers.

That triggers some distant memories for me on when I was a physics lab TA during my graduate school years. Most of us physics graduate students, at some point, have to TA either a discussion class, or a lab, or both. Now, unlike a lot of graduate students, I actually enjoyed doing TA work ... most of the time. I of course, hated the grading work and correcting homework assignments, but the actual TA work with the students, those I enjoyed tremendously. I think I empathized with the students and I recall how difficult it was for me when I went through similar undergraduate program. So I instinctively tried to do my best with such responsibility.

During the first semester of my Lab TA work, it was a challenge, very enjoyable, but also a rather rude awakening. The biggest challenge was trying to make sure that the lab reports that were written were actually the work of the students, and not just a copy of someone else's report, or from some "database". I learned from other students that one can find a complete set of pre-made lab reports kept at some fraternity or somewhere else. These lab reports corresponded exactly to the lab assignments being given each semester for the various undergraduate courses, and that includes the physics courses.

The thing was that, a few of the students didn't even bother changing a word of what they copied, so I ended up with lab reports with practically identical wordings. When I queried, the most common excuse was that they "worked together" and so simply produced one lab report for both. Of course, I didn't buy that, and emphasized to the students that the actual writing must be done individually, regardless on whether they worked together in the lab itself, or outside.

Well, you can guess what comes next. I then get practically identical lab reports (same numbers, same types of errors, same type of analysis, same number of significant figures, etc.), but the words have been changed a bit here and there to no longer make them carbon copies. Oy vey!

At that point, I could have easily threw my hands up in the air and stop caring. If they don't care that they're not learning how to do these things, why should I? But then, I saw the other side of this issue. What about the students who actually put in an honest effort, spent time actually doing the analysis and writing a report, but because they didn't copy off some "perfect" lab reports already in some database, they are getting penalized for a less-than-stellar lab report? I just couldn't live with the fact that honest students are getting the short end of the stick, while students who simply copied were not only getting away with it, but also getting higher grades!

{Now, you could have wondered why I didn't take more serious actions if I suspected students were cheating. You need to remember that it was my very first TA job, I was new, and frankly, I didn't want to get into such a big deal when I myself was still trying to get a feel on how to do the job. So as much as I hated it, I let it go, while the "offending" students continued to make just enough modification to their lab reports to not make them too obvious that they were copies.}

After that first semester of TA work, I became wiser for the next semester, and I was determined that those who wish to simply take the easy way out will not get away with it that easily. Being more familiar with the content of the experiments, I decided to go through the entire semester's worth of lab work to see if I can introduce something unique to each one of them. My observation was that most of the laboratory experiments that the students had to do were just too long, with too many tasks. Instead of learning a few things very well, the students ended up rushing to complete a lot of the measurements without learning much on what they did and why. Luckily, as a lab TA, I was given some flexibility in how I conducted each of the lab session. So I decided to do two things: (i) cut down on the number of tasks in each experiment, so that the students have a lot more time to do what's left, and (ii) introduce something new that isn't covered in the written lab manual. This last part wasn't as dramatic as one would imagine. The "new" stuff could be an extra measurement, or measurement done in a slightly different way, etc. For example, in the experiment where the students used a spectroscope to look at the various discrete line spectrum from various light sources from discharge tubes, instead of having them look at all 3 or 4 different light sources, I gave all the students one known source (hydrogen), and then gave each group an "unknown" source. The unknown source is not identical for all the groups, and I asked each group to see if they can identify the element they were looking at (they were given a chart consisting of the spectrum of various elemental gas). So the task they had to do wasn't too far off what the original instruction in the lab manual, but it did introduce a new element (no pun intended) to it.

So when the new semester started, I gave a briefing on what I would do for each of the experiments that semester, so that the students know fully that there will be new stuff not covered in the lab manual, and that I will be handing out instructions on changes for each lab session. In other words, there would be no surprises by the time they show up for each lab on what needed to be done. What transpired was rather .... er ... fascinating.

During the second experiment, the students were told (verbally and in the extra instructions that were handed out the week before) that whole sections of the lab will be taken out and something they won't have to do. In fact, the equipment to do those sections were not even on the benches. Strangely enough, when I received the lab reports the following weeks, there are groups of students with results from that part of the lab! Of course, I did a double take when I saw this, and not only that, we have the same "identical lab reports" all over again.

I didn't grade those reports. All I wrote on them were "Please See Me". So the following week, when all the students got their graded lab reports back, the group of students that received my note (I think there 5 or 6 of them) came up to me and asked why I wanted to see them. So I asked them how they did this experiment, pointing to their report. One of them started to explain how he did it. I then tell them that that's impossible, because the equipment for them to do that experiment wasn't around. In fact, that part of the experiment wasn't even set up. Well, I remember that you can hear a pin drop in the lab, because other students also suddenly realized what's going on. Still, one of the "guilty" students had the audacity on asking me if I was sure that it wasn't set up and the experiment couldn't have been done. I then turned to the other students in the lab and asked them if any of them saw that part of the set up. They all said "No". Essentially, I let their contemporaries reveal their guilt.

Having left no doubt of the fact that they've been caught cheating, I gave them the option of either getting a "Zero" for that lab report, or the ability to come back at the end of the semester, and redoing the lab. All of them opted for the latter, which of course, is more work on my part, but what the hey....

Several things happened after this incident. (i) all the students in that lab session now knew the deal, that I will look very closely at their report, and that there will be new stuff that they can't simply copy off something (ii) all the students that were caught cheating left my lab session - a few I think dropped the course, while others changed to another lab session conducted by other TAs (iii) I also gained other students who transferred into my session (I later found out that, not surprisingly, that the news traveled pretty fast among the students in the same lecture session).

There were minor issues of "copying" the rest of the semester, but I think everyone in the lab class rather knew that they have to write the report themselves and not copy off some previous reports. It created quite a bit more work for me, because I have to keep inventing something new and unique for each experiment. But my whole principle was not to prevent students from cheating, but rather I wanted to make sure those that did their work honestly were sufficiently rewarded. And I think, to some extent, that was accomplished because at the end of the semester, a student came up to me and told me that she appreciated that students who simply copied off previous lab reports can't get away with it in my lab class. She told me of this copying practice in other classes, and that's when I was told that the various fraternities do keep copies of lab reports, homework, etc.

In the end, I don't know if what I did made a difference in the overall scheme of things. I can't change people's behavior too much. All I know is that I simply couldn't just do nothing and let them get away with it that easily. I also knew that I had to be fair to those students who put in an honest work, or else there was just no incentive to be honest.

After that semester, I TA'ed only for one more semester before I received a research assistantship and didn't have to do any more teaching work. Still, I think I learned quite a bit in executing that responsibility. I certainly sharpened my skill as an instructor quite a bit, and learned what worked and what didn't. But most importantly, I realized that students will try to get away with as much as they can if you let them! I can only imagine how it is now, with all the portable electronic devices that they now carry. How do you know that they are using the calculator function on their mobile phone, and not text messaging someone for the answer, or surfing the web looking for the answer?


1 comment:

hps said...

Interesting post. I am physics student myself, but I never copied a lab report and, as far as I can tell, neither did one of my colleagues. A physics study is a lot of work, everyone knows that. If one is not up to that, he/she should study something else. I really want to know, how these students get through theoretical physics exercises, which are, at least at our institute, much more work than experimental labs.