Our expert advice remains unheeded


Once in a while, tropical biologists get bot flies. We sometimes find this out while were are in the field. But on five occasions, my students have returned to the US, and then discovered that they are hosting a bot. They all contacted me for advice. I told them a few things, but the most important one was:

Whatever you do, don’t go see a doctor. That could be disastrous.

Nonetheless, three of these students went to the doctor.

The bot fly Dermatobia hominis, that came out of my student's arm while he was sleeping. Photo: T. McGlynn

A mature bot fly larva, Dermatobia hominis, that emerged from my student’s arm while he was sleeping. He intentionally reared this one out and allowed it to pupate. Pencil is for scale. Photo: T. McGlynn

This has always troubled me. Without any additional context, it looks like the students just didn’t trust me, and thought that I’m stupid. At the very least, it shows that they trusted their own intuition over my recommendation based on a long history of experience. It shows that they followed the misinformed advice of family and friends over the judgment of the person who was responsible for the trip to the rainforest.

It shows that when it really really really counts, my guidance ain’t worth much at all to my own students.

I don’t give students this instruction without an explanation. I tell them that nearly every doctor in the US will want to cut the creature out. History shows that bot fly larvae are smarter than doctors. If you present yourself to a US doctor with a bot inside you, the predictable result is that you leave the doctor with your bot inside you. You will also leave without a large chunk of flesh that the doctor removed in a futile attempt to get the bot. Sometimes the bot is killed in the surgery, but not excised, which leads to a rotting carcass and infection, and the need for serious antibiotics. I tell them that, if they can’t get it out using the variety of techniques we’ve discussed, and they feel compelled to go to a medical professional, they must go to a vet and not to a doctor. (The students who did the opposite of my recommendation came to regret their choice, if you’re wondering.)

These bot fly incidents are convergent with a recurring incident in a non-majors laboratory that I have taught. The week before an exam, I hand out a review sheet that specifies the scope of the exam. I then tell the class:

Check out item number three on the review sheet. This is a straightforward question about osmosis. The answer is that the volume of water in the tubing will “increase.” The correct answer to this question is “increase.” Just circle the word “increase” and do not circle the word “decrease.” I’m letting you know the answer to this question now and I guarantee — the odds of this question being on the exam next week are 100%. I promise to you, with all of my heart, that this question will be on the exam word for word, and this one question will be worth 20% of your grade on this exam. You don’t want to get this question wrong, and I’m telling you about it right now. So, be sure to write down in your notes that this question will be on the exam and be sure to remember the correct answer when you see it.

The reason that I’m being really obvious about telling you about this question its that in the past, half of the class has gotten the answer to this question wrong. It’s a simple question, and it addresses the main point of the lab we conducted for more than two hours last week, but still, lot of people got it wrong last semester.

You should know that those students also were told in advance what would be on the exam. Just like I’m telling you right now. They knew that 20% of their exam hinged on remembering one word, “increase,” and still the majority of them got it wrong. I’m telling you this now because I don’t want you to suffer the same fate of those other students. DON’T BE LIKE THE STUDENTS FROM LAST SEMESTER WHO WERE FED THE ANSWER AND THEN GOT IT WRONG THE FOLLOWING WEEK. Just remember that “increase” is correct and the other word is not correct. I’d like you to remember the physical mechanism that explains this osmosis, but more than anything else I’d like you to demonstrate that you can be prepared for the exam and remember this small fact which I am hand-feeding to you right now. I promise to you this exact question will be on the exam Learn from your predecessors, don’t make their mistake. I’m giving you 20% of the exam for free right now, so write this down.

As I give this slightly overwrought speech, the students are paying attention. There is eye contact. They might be note-taking activity. Nobody’s on their phone, and nobody’s chitchatting.

When I administer the exam, more than half of the class circles “decrease” instead of “increase.” This has happened four times, and each time it happens a little piece of my heart dies.

As you can imagine, many of the students in our non-majors class are as disengaged as humanly possible. By no means is this a difficult course, even with low standards, but the fail rate for the corresponding lecture course is about 50%. The students who fail are clearly doing so because they aren’t even making the slightest effort. The reason that I keep giving students that same question over and over, and give them the correct answer over and over, is to give me some reassurance that the wretched performance by so many of the students is not my fault. I do this to grant myself absolution.

In these labs, each week is designed to give students the opportunity to develop their own experiments, find new information on their own, and work together to solve problems. This happens to some degree. But half of the students do not exert the tiniest amount of thought about doing what it takes to pass the exam. Why don’t they even try even the slightest, despite my best efforts to both inspire and feed them the right answers?

The students who fail these exams trust their own intuition, or some other model of behavior, instead of my own advice. If anybody is the person to tell you how to pass the exam, it should be the professor who is telling you the answers to the exam. But in this case, the students weren’t even bothering to look at their notes for five seconds before stepping into the exam. They’ve presumably heard from other people that work is not required for this class whatsoever, or perhaps they don’t care for some other reason. All I know is that no matter what I do, I can’t get these students to care about their grade on the exam. Some are excited about the labs, but not necessarily in passing.

So, what do the bot fly story and the osmosis story have in common? No matter how hard we try, sometimes our students won’t follow our recommendations. At least, not mine.

We are fancy-pants PhD professors, with highly specialized training. We’re paid to be the experts and to know better. That doesn’t mean that our words are prioritized over other words. Anything we might say just ends up in a stream of ideas, most of these ideas just flow out as easily as they flow in. It’s no accident that my teaching philosophy is “you don’t truly learn something unless you discover it on your own.” This is why I focus on creating opportunities for self-discovery in teaching. This is the only way in which people truly learn.

No matter what we professors might say or do about bot flies, or studying for exams, or anything else, other people will rely on their own judgment over our own. Even when the experts are overtly correct on the facts, even smart people often use misguided intuition when making important decisions, even when they are obviously wrong on the facts and the experts are overtly correct.

It’s easier to listen to other people than it is to heed their words. As a professor and research mentor, I’ve given up on the expectation of being heeded. I just work to speed up the process of self-discovery of important ideas. But, for the most part, I still don’t know how to do that. I think it’s an acquired skill, and a craft, and I think I still have a ways to go.

21 thoughts on “Our expert advice remains unheeded

  1. More likely: the student’s mom didn’t trust your advice.

  2. Regarding the osmosis problem- there’s likely to be some fundamental misconception that hasn’t been properly challenged at work. No matter what you tell them, the misconception will win. My personal version of your osmosis question is “what is yeast.” With U of A students, we could have 2 days of lectures with pictures, all about yeast as an organism, followed by a lab where yeast was used to demonstrate glycolysis, and 50% of them would still answer that yeast is a mineral on the test. This happened 3 years in a row.
    I recently took a teaching workshop by Dr. Ed Prather where we learned how to work backwards, breaking problems into the smallest pieces to find out exactly where students were being hindered by misconceptions. Once we did that, we could directly work on the misconception with them. I usually hate pedagogy courses and find them worse than useless, but this was fantastic. In the case of the yeast, I think the idea that it is a powder that comes in a jar or bag like baking powder simply overrode anything I told them and the evidence we saw in lab. Taking it from the jar and watching it physically grow on a plate might be the solution I needed. Unfortunately this strategy works better for smaller classes. Ed’s strategy for lectures of 300+ was to have previously worked out most of the major sticking points through years of experience, then design problems to be worked on together by everyone in the room with small steps that revealed the misconceptions. It helps that he has a flock of TAs and undergrad helpers working the room.

  3. Well…My 2 cents: expert advice is overrated, based on people’s everyday experiences. I have been given stupid advice and erroneous diagnoses by a variety of professionals (including medical doctors). In the few cases where the expert was right and I did not follow the advice, I learned my lesson. Looking at it from the bright side, those students are exercising independent judgement :)
    Re lab classes, one approach that has worked for me is to have a review session where students develop questions themselves. I make a list of stations (this is for a practicum exam): osmosis, different microscope slides etc. and assign them to students in pairs. I review the questions and then students quiz themselves. If the questions are good, I incorporate them in the actual exam. Somehow the questions sin in much better, because they are doing it themselves.

  4. The osmosis situation has two separate problems, or at least, mysteries of human nature that I have yet to understand.

    The first one is that the bulk of students in this class are not focused on studying at all. I mean, whatsoever. The fact that they did a whole inquiry-based exercise on osmosis and that they still get it wrong is only the tip of the so-called iceberg. (Before they ran their experiment, though, even more developed the hypothesis that osmosis would work in the opposite direction, then they developed and ran an experiment to find out the way it works, and wrote up a report explaining their findings. Then, many forgot about it all within a week.)

    The second mystery is that the students simply don’t even listen or care to what I have to say about free points on the test. Which is, allegedly, what students are craving for, according to the unfair nasty stereotypes of undergraduates. The only explanation, which I think might have some root in truth, is that these students are not in the class to pass it or to learn, but there’s physically in the classroom for another reason that doesn’t have to do with earning a passing grade or learning the material.

  5. In my youth I worked a lot at a bird observatory, and part of the work was to give guided tours to tourists and school classes. Really a great thing – you show them the bird, ring it, measure it and talk about all the wonders of bird migration. I must have done it some 300+ times and was pretty good at it. Still, even after a great show, you would get questions that made it pretty sure they hadn’t paid attention. My favorite question of all times is: “Do you kill the bird before or after you ring it?”

    And that was after a half hour demonstration where I had ringed and released at least three birds in front of them…

  6. “Bot flies?” Dear goodness gracious. I’m not going to sleep tonight.

    Makes me glad I examine irradiated fuels out of the reactor, instead — you have to respect them, but they don’t suck your blood!

  7. I studied in Costa Rica as an undergrad and worked in Panama after graduating and I wanted, both times, to come home with a bot fly. I never have. I need to go back.

    This story…I don’t know whether to laugh or cry, honestly. I read that aloud to a colleague today and he just shook his head and said, “I’m not surprised” which also made me want to cry.

    While not on the same level, every exam I write, I always write more questions than students have to answer. Before they start, I read the directions, which clearly are written on the papers in front of them, that they can only answer 4 of 5 (or whatever the case may be) and that, if they answer more, I will only grade the first 4. I get at least 10 out of 40 who write all of them, in each of the 5 sections. The final I gave on Monday took about 10 people an extra 20-30 minutes and sure enough, they’d all ignored the directions and answered every question.

  8. Telling someone “not do something”, without additional information, is a good way to ensure that some people will do it. Telling me to circle “increase”, without understanding, will help me to remember that the answer is important, but it is unlikely to help me remember the answer.

    It is also important to know that a student infected with a bot fly larva is not a diagnostician. They simply know they have a medical problem and need a dianosis. Doctors diagnose. The fact that doctors can diagnose, but not be aware of the best treatment is a problem of the medical profession, not the problem with your student. It is a common problem, not limited to bot flys. In many cases, it is even difficult, sometimes impossible, for the doctor to know the best treatment for many illnesses that they are equipped to diagnose. What is the best treatment for a bot fly larva? Is there a best treatment, or simply some that are better than others?

    • “I told them a few things…”

      “I tell them that, if they can’t get it out using the variety of techniques we’ve discussed, and they feel compelled to go to a medical professional, they must go to a vet.”

      Before you comment, I recommend might want to read more carefully. Feel free to check with a doctor if you disagree with this recommendation.

      • Is there a way to communicate with you outside of this public forum? I would love to respond, but I don’t want to reply in public. I don’t see your email anywhere… you have mine.

  9. So I’m curious now–why doesn’t it work to cut the bot flies out? Do the larvae burrow deeper or have other defense mechanisms?

    • They are mighty sneaky and can wiggle around and hide. There is, apparently, more space in there than you might think. For whatever reason, when doctors try, they inevitably fail. I’ve heard that cutting them out is also the fashion in San Jose as well. They deal with them on occasion and might get them, but it’s a mighty big operation. Meanwhile, there are easy ways to get them out without surgery that will work well. Those are well documented and you can talk to anybody who’s worked for a good long while in the Neotropics about those. That’s a whole ‘mother blog post, I imagine.

  10. Dealing with botflies is surprisingly simple. I got rid of them in South America with a simple piece of non-breathable tape (duct-tape works well, as does athletic tape). Of course, a hat and long-sleeves go a long way in preventing them in the first place.

    As for the not listening either to the test question preparation or to the advice about doctors… I’m not sure that even duct-tape will help with that.

  11. I teach too, Biology of Insects and Spider, and Gen Bio, Bio 101. About half in each class drop or don’t pass with a C or better. Perhaps we should stop referring to those who show up but don’t participate one way or another, as students but rather as attendees.

  12. My Alma Mater was known as a strong pre-med school. On the first day of school, seemingly every freshman was declared pre-med. Then they met Dr. Shew. The first biology class was the “weed out class.” We had 4 exams. Second week of class, a week prior to the first exam, he took about 20 minutes to write the formula for cellular respiration in 6″ tall characters on the board. He told us we would see this on the test. More than once. He told us to write it down. As he finished each part of it, he repeated that advise. Half the class got it wrong on the exam. Almost every one of those became some other major the very next day. I’ll bet you 30% of those who got it correct are doctors today. I know several of them are.

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