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CU astronomy »

Courses taught since 2010 (click on semester to see summary/feedback from students):

Fall 2021: Astronomy UN2001: Introduction to Astrophysics I

I decided to go with my now-usual two-part exams. Here the class is taking the midterm individually.

And this is a short video when they switched over to taking the exam in pairs.

I managed to insert one my favorite activities, using one's hands to measure angular sizes, even in this class.

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Spring 2021: Astronomy UN1836: Stars and Atoms

At least I learned from my mistakes: despite having taught this class four times already, including in the first COVID semester (so I already had a bunch of lectures + materials ready for a virtual class), I asked for as much help as possible. We are lucky enough to have a glut of potential TAs, so I got two, a first. I also got two graders. And I'd say that more than anything else I did that made the biggest difference, as having all that help meant I never felt I was at risk of falling behind the way I did in the fall. I think the lesson here is that an all-virtual format doesn't require fewer resources--to work well it probably requires more: more TAs to monitor the discussions in the Zoom breakout rooms, to organize one-on-one meetings with students (so you don't wake up the week before finals and realize they're all struggling), to provide more options for office hours; more graders to make sure homeworks, lecture tutorials, and exams are being turned around quickly even if they are in part or even primarily auto-graded via Canvas.

Other notes: the acceleration that always seems to happen when we get to the final third of the class happened again, and I had to fall back on pre-recorded supplemental lectures on star formation and the evolution of high-mass stars to more or less cover the course material. I was glad to have those from last spring, and ultimately the two totaled just about one lecture, but it's still a bit troubling that I can't quite fit everything in (especially since this semester I had 25 class periods, which seems like more than usual). On the other hand, I was able to fit in, for the first time ever, a lecture tutorial on stellar evolution (on the Sun). It would just be nice to have the time for at least one or maybe two more of those, but that would definitely require cutting out things earlier (maybe it's time to say goodbye to more of the asides, e.g., on the age of the Earth).

Stars and Atoms students taking the group final in a Zoom breakout room, April 2021.

There were any number of technical issues, of course. It took me a while to figure out how to get the polls working in Zoom, and I didn't always set them up properly. (I also almost never had the students breakout to discuss their answers to the polls--just took too long.) At least once I clicked on "leave meeting" when I meant to leave a breakout room; fortunately I don't think the students noticed, and I made sure to assign the TAs as co-hosts in case I did something like that again. I had frequent issues with either Zoom or Chrome freezing, which was always irritating, especially since I was teaching from my office computer.

I also managed to have a Canvas SNAFU for each exam. After the first midterm, I went to make a copy of the exam to set it up for students who were taking it a day or two later--and somehow in the process proceeded to erase the group version of the exam, complete with all the answers the students had submitted. There was no recovering those exams, sadly (it took CUIT several weeks to confirm what the internet told me in 30 seconds); I don't think that in 20 years of teaching I've done anything quite like that. Then, for the second midterm, in response to the feedback we got after the first, I let the students see immediately whether they got the right answers to the multiple choice questions. The result was that when they got together to do the group version, there was no real discussion about those questions--instead, one would say "I got that one right" and that was the end of it. Finally, for the final, I forgot to click "scramble answers" (why isn't that the default...?) and the answer to every multiple choice question (75-80% of the exam) was therefore A. Fortunately, only a couple of students noticed, and if anything it made them doubt their answers, but still.

Having the two TAs meant we were able to set up those one-on-one meetings I mentioned above after each midterm, although it has to be said that only the first set seem to have been useful (it didn't help that the grad student strike also took the TAs out of the equation for a bit). I assigned the students the three-question post-exam wrapper and the TAs used that as the basis for a conversation about their performance in the class/on the midterm. Definitely something to keep if possible. The second set might be made to be useful if it can be done well before we get into end-of-semester scramble and perhaps is more explicitly focused on preparation for the final. As for having two graders, that meant I didn't have to get graduate students to grade the exams (a net win, in my opinion, as I didn't have to do any training to bring them up to speed) and I was able to squeeze in seven homeworks (granted, one was the eggs-on-the-equinox classic, but still). It seems like it might be possible to get to a homework a week, although I don't really know if that's desirable.

Random thoughts: I think having an office hour on Zoom is something I'll do going forward. And the precipitous decline of the exit poll continues--I eventually gave up on giving the students a minute or two at the end of class to fill one out. Maybe it's time to retire that one.

The class evaluations didn't give me much insight. 75% of the students filled it out, which is good, but very few provided comments, which I generally find more useful that the numerical scores (for the record, 60% of respondents rated the class excellent/very good, 76% rated my teaching effectiveness as excellent/very good, and 80% would definitely/probably recommend the class while 20% would probably/definitely not recommend it--I'm polarizing!). But there was an interesting contrast between two answers to the question asking for an evaluation of my teaching:
"I particularly appreciated the in-class aspect of lecture tutorials. Not only did they make zoom more personable, but they allowed me to retain, understand, and learn the material much much better than if it had been just straight lecture."

"I feel like he could have used class time in the virtual format a bit more efficiently (sometimes we spent too much time in breakout rooms/discussion when lecture would be more optimal)."

Sorry, student number 2.

As always, the final included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"This class surprisingly has helped me reshape how I think about approaching science. It has not only taught me how to correctly apply the scientific method, but it has made me comfortable with the idea of science (being a non-stem major) and engaging in discussions of space, planetary evolution, and even atomic scales."

"This class has caused me to think about the underlying causes of everyday phenomena like static on my hair brush or the change in temperature of my coffee. It also has made me think about the profound vastness of the world we inhabit in comparison to our relatively short lives."

"It has made me appreciate the importance of being open to new explanations, and being conscious that there may be evidence we have yet to see because we don't yet have the technology to collect it. It's therefore important not to dismiss new theories only because they are different from majority consensus about how the universe works, and not to insist on clinging onto old theories."

"It has made me realize that science is kind of crazy with all the small probabilities that events leading to the formation of the Earth had but yet we are still here somehow."

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Fall 2020: Astronomy UN3101: Modern Stellar Astrophysics

My first time teaching this class in four years, and it was definitely challenging. Setting things up to teach virtually was not all that hard, just time-consuming: I had to reformat the slides so that they weren't overwhelming (e.g., by breaking up the steps in a derivation) and to add all my notes to the Google slides to have them available in Presenter View.

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Spring 2020: Astronomy UN1836: Stars and Atoms

I am grateful to my students for sticking with this class as they, I, and everyone else underwent mass upheaval midway through the semester. I did not find the technical part of the transition to online teaching particularly challenging (although there were plenty of technical hiccups along the way), but it was often hard to see the point of putting together my biweekly lectures when the world seemed to be collapsing.

There were no official course evaluations this semester, a university decision that I do not fully understand. But we were allowed to conduct our own surveys if we so wished, and a number of questions were suggested. Twenty-one of my 44 post-pandemic students filled out my anonymous 13 question survey. The main takeaway was that the vast majority did not feel that the transition to online teaching disrupted what one might call the class fundamentals: whether I used textbooks and/or course materials effectively, whether the instructions for completing activities, assignments, and/or readings were clearly stated, and whether they knew how their learning was being assessed. The percentage of students who agreed with these statements went from 81%, 95%, and 95% pre-transition to 81%, 90%, and 86% post.

There were also questions about which technological tools we used were effective for remote learning. The respondents largely found the live Zoom classes to be effective (86%), and also appreciated having the class recordings available (81% found them effective). The answers were much more mixed when it came to using breakout rooms, the Zoom feature I used to try and recreate the paired work that is so central to my classes. Roughly the same number of respondents found the breakouts effective and somewhat effective (24% and 29%), but 38% found them ineffective. While I like the feature, it is time-consuming to set up, and the students often were slow to join their breakout rooms. The bottom line is that it worked OK for doing lecture tutorials, but for think-pair-share questions it was way too clunky, and I found myself using the rooms less and less.

Still not sure about giving exams to students to complete in pairs? Check out the two videos above. The left one is my Stars and Atoms students taking their first midterm on their own. The right one is them taking that same exam in pairs after completing it on their own. Which classroom would you rather be in?

The second midterm and the final exam were both given as CourseWorks quizzes. I toyed with the idea of preserving what I have done in years past (and indeed for the first midterm), namely having the students take these exams individually and then with a partner. But ultimately the logistics were too daunting (I had students in Asia, all over North America, and in Europe) and it seemed unfair to require this. The quizzes feature is neat, in that grading is automated and straightforward for multiple choice questions. But I realized that there are some drawbacks to this feature for certain kinds of questions: for example, the automated grading of fill-in-the-blank questions requires that you list all the possible writings of the correct answer. I did not list "blackhole" or "Type 2," only variants of "black hole" and "Type II," for example... a word to the wise.

The final once again included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"Yes, completely. I learned how science is a way of structuring our minds to gain perspective, especially when thinking about the infinitely small and infinitely big. This class really opened my mind to the process of science as a constant research process, where nothing should be taken for granted."

"The asides about astronomers' unique, textured lives and the historical contexts they lived in reminded me that science isn't produced in a void. The think-pair-shares taught me that science is a much more collaborative venture than I thought it was."

"There is more of an artistry, and a creative outlook demanded by science than is evident at the surface level. While scientific facts are indisputable in an inarguable way, the contextualization and the creative outlook that sparks the process of exploring for answers requires an imaginative perspective and a sense of vision that is not obvious from the outside."

"[O]ne does not need to be brilliant to pursue the essence of the Universe, just patient and curious."

"Definitely. What it has definitely made me appreciate more is just how much cooperation goes in to making scientific discoveries. I didn't know many of the scientists who were mentioned in the class, and that says a lot about how we tend to view science - there's this one genius like Einstein who figures everything out on his own. But Einstein built on centuries of work before him, without which he could not have made the discoveries he did. [...] Beyond science, it has also changed the way I think about life, and I'll definitely be thinking about this class for years to come."

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Spring 2019: Astronomy UN3998: Independent Research

My first time teaching this course, which is generally designed for undergraduates who are writing a senior thesis. There was no pre-existing format for the class, so I decided to have it meet once a week for an hour and to focus on helping the students with things that support their research. In practice, this meant more-or-less brief discussions of how to develop a mentoring network, how to get the most out of your mentoring relationships, what is and isn't ethical research behavior in astronomy, and what research and life tools they might want to start using (I'm out of touch on this, of course, so surveyed our grad students to find out what tools they use most. I did set up a Slack channel for the class, so I can't be accused of being 100% dinosaur.). In addition, the students gave two talks: a public one as part of our Friday-night lecture series, and one to the department as part of a special end-of-year pizza lunch (for which they submitted their abstracts).

I think the course worked well, and I enjoyed it. My only regret is not appreciating how stressful for the four seniors the denouement of the graduate-school application process would be, and it makes me think we (as a department) should be thinking more about how to support our students during that process.

The Fab Five after giving their pizza lunch talks on Tuesday, May 7, 2019. From left to right: Andy Tzanidakis (GS'19), Miguel Martinez (CC'19), Betty Hu (SEAS'19), Marlee Smith (CC'21), and Harrison Cook (GS'19).

The feedback was very positive, although not everyone filled out an evaluation (even though I thought I required it! I don't understand). Sample comments:
"I wasn't sure what to expect from an independent research course that required me to [meet] in-person every week. But I really liked this! The most useful part of the course was definitely receiving multiple rounds of feedback on my presentations and learning what does/doesn't work from the other students' presentation, but I also liked the weeks where we talked about research ethics, communication in research, etc. I preferred classes we learned very hands-on skills as opposed to more abstract classes (example: "what does your research support network look like?")."

"A great course. I really loved that Marcel tried to prepare us for after the class and had us give several presentations. This is something really important in astronomy that I had no experience with yet. It was hard for me, but rewarding."

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Fall 2018: Astronomy UN1836: Stars and Atoms

No major changes to the course structure: we did 12 lecture tutorials (LTs) in class, there were six homework assignments (two of which were only worth 50 points), several of which included an LT, and I gave two midterms (both of which included an LT) and a final (which did not). I had students take the exams first on their own, and then again while paired up with a partner, with both exams graded and students getting to keep the highest score (if it came on the group exam, it was the average of the solo and group score). The pace of the course felt right to me, although I did not get a chance to talk about the instability strip at all, and the Big Bang nucleosynthesis piece did get squeezed in right at the end. Cutting a bit more material early on would probably be a good idea, as some students clearly were frustrated by the time it took to work through the fundamental physics before we got to the astronomy (it really should be called Atoms and Stars!). One small wrinkle: toward the end of the semester, when I was out of LTs and running out of think-pair-vote-share questions, I inserted a couple of breaks into the lectures: a couple of minutes for the students to get up and stretch, etc. Too many of them just went straight to their phones, in my opinion, but whatever...!

Overall the course evaluations were excellent. Close to 80% of the respondents said they would recommend the class to another student, which I take to be a good sign since, as one person said of the class, it is "Mid range but not an easy A for science requirement..." Maybe that should be on the syllabus.

Once again, I added two questions to the course evaluation: whether the LTs, which were graded for completion and collectively contributed about 10% of the students' grade, should be graded more like traditional homework (i.e., with points taken off for incorrect answers), and whether students wanted to keep the group exam or go back to individual exams only. Almost no one wanted the LTs to be graded as homework, which is good, because there is enough grading to be done already. A few people mentioned wanting answer keys, however. That is something that I have generally resisted, but I will think about that more. As an aside, I think I need to be stricter with the LTs; I allowed students to complete them even if they missed class, and that became a problem as the semester wore on and backlogs of LTs appeared on my desk. It was frustrating for me, and I think for the students too, because I couldn't keep up with late submissions (and therefore handled an inordinate number of "I have a 0 on CourseWorks but handed in that LT last week" emails).

As for the exam question: the vast majority preferred the current system to only taking the exam on their own. Quite a few of the people who did not like this system (and some who did) complained about the relative amount of time given to the two exams (currently 2/3rds + 1/3rd), which meant that for the midterms in particular the group exam was rushed (25 min). This is a fair point, and one that had already been made to me in Fall 2017 (but I had apparently forgotten that!). Next time I promise to move toward more of a 50/50 split between the two. The challenge, as always, is figuring out what the right number/difficulty of questions is for a given amount of time...!

Oh, and one real mystery this semester: as per usual, I ended each lecture by asking for exit polls, but the number of responses steadily declined week by week, and by the end of the semester it felt like a pointless exercise! It was baffling. My best guess: it might have been because I consciously cut down on the number of digressions at the beginning of lectures, and so the exit polls may not have seemed as relevant as they did to past students.

Stars and Atoms students learn to use their hands to measure angular sizes, October 2018. The object whose size they are measuring is the Eiffel Tower.

Stars and Atoms students working in pairs on their final after having first completed it on their own, December 2018. One of my favorite aspects of giving group exams is the amount of noise in the room when the students get a chance to talk over questions. I find that really energizing. (Oh, and if you're paying close attention: you're right, it's not the same classroom! They made us move for the final, which was mildly irritating. In fact I almost missed this change, which would've been awkward...)

The final exam once again included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"Yes, it certainly has. Obviously I understood that there is a lot we know and even more we don't know, but I never knew the extent to which we understood stars and their processes. For some reason I always assumed the inner mechanisms of stars were a mystery and that we were only guessing, but the processes by which we understand them now are incredible. [...] I also realized how much we were wrong about in the past, and how important it is in science to continue testing and theorizing to find what could be a correct answer, even if the answer of the past seems correct in some ways. Everything can be improved upon."

"I'm very used to being taught large amounts of information in different scientific disciplines but not being shown that they connect or how they overlap. As I was reviewing for this exam, it became clear to me how "interdisciplinary" everything is, in a way. When we started the course I never would have expected learning about nuclear forces and magnetic fields would help me understand how stars generate energy, but after finishing the class it is obvious that all of it ties together."

"I used to view myself as outside the scientific realm. I did not really engage either because I thought it was too complicated or uninteresting. Now however, I think science is something that is for everyone, at least to some extent. I will certainly be more attentive to scientific discoveries and science in general in the future."

"I really enjoyed how you almost told the course like it was a story. With constant asides and little facts/history about the scientist who developed whatever we talked about."

And best of all, the answer that made me feel (finally!) that my corny jokes are not in vain:
"Thank you for teaching this class with your humor and sorry for not understanding your physics jokes sometimes. As I was reviewing, though, I finally understood them."

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Spring 2018: Astronomy GR9002: Graduate Seminar: Stellar Ages: Promises and Challenges

This seminar took as a starting point David Soderblom's 2010 review, The Ages of Stars. After a very quick review of the basic of stellar structure (three lectures!), the class was split up into three groups, and each was responsible for two presentations. The first set of presentations was on what I think are the most currently discussed approaches to age determinations, namely isochrone-fitting, gyrochronology, and asteroseismology. The second set was on more boutique or novel approaches: lithium (both depletion and the depletion boundary), nucleocosmochronometry, and kinematics. The goal was to use the review to provide the necessary background and then to fill in what developments there have been over the past decade or so... which in the case of asteroseismology and kinematics, for example, are significant!

Coupled with these presentations, the graduate students also designed in-class exercises (e.g., we used abundance measurements to estimate the ages of several stars). We also had a couple of combined seminars/workshops with Phill Cargile and Stephanie Douglas that allowed us to get our hands dirty with MINESweeper (a Bayesian isochrone fitting code that uses the MIST models) and with measuring rotation periods in K2 data. In both cases the students' work was contributing to real research, and I was very happy with that aspect of the seminar.

My thanks to Rose Gibson for creating this D&D-inspired stellar ages alignment chart...

The feedback was very positive, although the class was small (seven students) and not everyone filled out an evaluation. Sample responses below.
"This was a FANTASTIC seminar! I found the learning goals for the semester were super clear: we set out to look at a specific problem in stellar astrophysics of determining the ages of stars. Marcel gave a brief series of really good lectures to give everyone a good foundation in the basic ideas, and then the rest of the seminar was structured around building off of one review paper, with student presentations about 6 key topics. The overall structuring, combined with the student presentation aspect and some really interesting and fun hands-on activities throughout the semester made for a really good overall learning experience in my mind!"

"I thought the course was excellent. It was engaging and I felt like the out of class assignments were relevant to the course material. I particularly liked the activities and workshops that gave us some insight on how the various techniques worked."

"Marcel's structure for the class really resonated with me. His initial lectures were really good, as was his guidance and feedback for our presentation. He was also really good about giving us time during our presentations to try and answer questions that arose in the class before jumping in and providing his answer."

The only negatives mentioned in the evaluations had to do with the scheduling and the timeliness of my feedback. The former was erratic, which meant that we crammed quite a few classes into the final weeks, and the latter was slow... it's true!

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Fall 2017: Astronomy UN1836: Stars and Atoms

For some reason I didn't immediately reflect on this course, and now (summer 2019!) of course I have no recollection of any essential lessons learned...! I think in part this was because I was feeling a bit burned out after teaching two intro courses back-to-back...

Anyway, looking at the course evaluations now, they were very positive, with 28/30 respondents saying that they would probably/definitely recommend the course, which is what I always think of as my bottom-line evaluation question. One thing that I find slightly strange (and I don't think this is the first time this has happened) is that my students generally rate my class as having a lighter workload relative to other Columbia courses with a similar structure (fully 2/3rds of the respondents said that this time) and yet they complain about the homeworks being too hard or there not being enough clarity about what material is important to know for the tests. Those criticisms may be fair, but I wonder if the expectation is somehow that things are going to be easier than they wind up being simply because they're not being over-worked.

Meanwhile, I did have the good idea of asking two extra questions on the evaluation. The first was about the group exams: "What did you think of the group exam concept? Would you have preferred to take the exams only on your own? Why?"

From a basic "yes/no" perspective, the responses were overwhelmingly positive, with only one of 26 respondents flat out saying they would rather do the exams on their own. Below are some quotes, which also provide some nuance to that landslide:
"I like the group exam concept because it definitely helped my grade on both occasions. While working with my partner, I was able to better understand the questions I might have gotten wrong on my individual exam, and do the same for the other person. It is often helpful to be able to talk out a problem with another person, so I found this component useful."

"I really enjoy the group exam concept. I think it allows for an opportunity to perform better on the exam when you may not have understood something perfectly the first time around but understand it better when you are working with a partner. The only suggestion I would have for partners is assigning partners to people. I think this would make it easier and less awkward to find somebody to work with, while also getting more people in the class to interact with one another."

"I was a fan. I might give the group exam slightly more time though, just because even with two minds working, there's a limit to how fast one can write an answer, so leaving time to collaborate before writing sometimes makes the timing on the group part very tight. It was nice to know I had someone to fall back on if I was really really confused by a problem, and it made studying for exams not as harrowing as it is in my other classes."

That first response is exactly why I went to this sort of exam, of course, so it was very gratifying to see several students express some version of that idea. But the two other ones highlight the main issues people identified: how people are partnered, and how much time was allocated to the partnered version of the exam. Currently I have students pair up with neighbors early on in the course, without imposing much in the way of requirements (I say something about not partnering with someone you know well, but I don't really enforce that). I then force students to pick a new partner after the first and again after the second midterm. I think this is fairer, in that bad pairs are not stuck together for the duration of the class, but the students pretty clearly do not like it (or at least some fraction of them do not).

As for the second issue, I think it's clear that my idea of doing the solo exam with 2/3rds of the time you have and the group one with the remaining 1/3rd is not the best (this was also a big part of the feedback I got in Fall 2018). So next time around I will aim for a 50/50 split.

The second question was about the lecture tutorials: "Would you have preferred to have the in-class lecture tutorials graded more like traditional homework? Why? (As a reminder, they collectively counted for 5-10% of your final grade, so that there was only a small penalty for missing even a few.)" Here again, the answer trended strongly in one direction, with the vast majority of students liking the current way they were handled.

Sample quotes for context below:
"It was good that the lecture tutorials were not graded like homework, because as a result, I felt more willing to engage without the fear of being penalized if I was wrong. They were helpful certainly to anyone's grade, but honestly they were most helpful later in the class and in tests as thoughtful aspects to reference back to, and remember class discussions. I found them to be engaging distinctly because they were NOT like homework."

"No. I appreciated the low-pressure yet high-reward system of the lecture tutorials (high reward because of the added comprehension of the material that resulted form being present in class to complete them). It may have been considered burdensome to treat it like traditional homework."

"No, I really liked the way lecture tutorials were graded. It allowed me not to worry about getting every single thing perfectly right but rather focus on understanding the larger concepts. Additionally, I think it provided an incentive to attend lectures on a regular basis."

The main concerns expressed were about the lack of a key, which is something I have been told before, and about the lack of detailed feedback on answers (which in a sense is the same concern). I have been resisting the pressure to hand out keys, but I suppose I could request that the graders give more detailed feedback...

Stars and Atoms students learn to use their hands to measure angular sizes, October 2017. The object whose size they are measuring is the Eiffel Tower.

Stars and Atoms students working in pairs on their midterm after having first completed it on their own, November 2017 (I definitely need a tripod!).

The final exam once again included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"Yes! The biggest way its [sic] changed my thinking is that I've realized how much science doesn't know. Also, I've realized how impressive it is that science does know what it does! When someone says that a star is blue and hot and far away, you might think "OK... cool." But when someone explains that a star is blue and hot and far away... and here is the way we found that out, then you realize how amazing it is that we have all the knowledge we do. Now I see science, and astronomy especially, as being one giant collaboration between different men and women* throughout all time, with each little discovery having so many implications for what else it can help us discover.
*Also, I've never taken a science class that had so much info that women had discovered until this class. It's awesome how many women astronomers there have been!"

"It [...] bridged together the experimental and theoretical parts of science, which I've not experienced before. The universe is so vast that there are huge limitations to what can be observed, and we have to work with that information to find out most other facts. That in itself is mind-boggling to me."

"Before taking this class, I had no background in astronomy and was not a big fan of science in general. Although this course was not overly challenging for someone with a non-STEM background, I definitely had to work harder than some people to understand the concepts. But I think because of that I have ground more interested in the topics we discussed and I feel like my grasp on the aspects of science we covered has becomes considerably less tenuous. So, I am not as afraid of science anymore 🙂"

"[...] I think the biggest way that this class has changed my perception of science is by informing me of the background of the scientists. I was surprised that these scientists failed (and sometimes a lot before finding a solution). These scientists suffered from bad mentors, and struggled greatly to create these scientific contributions. Above all, this class taught me that like the long & arduous process that is stellar evolution, both science & thus success take time. Not only did this class change my perception of what I originally thought was an instantaneous process, it changed my perception on the definition of success."

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Spring 2017: Astronomy UN1403: Earth, Moon, and Planets

I'm going to stop counting how often I've taught this class. Two changes relative to years past, one small and one large. The small one was the addition of lecture tutorials; building on my experience in Stars and Atoms, I tried hard to do about one LT a week (I failed). Unlike the first time I used them, I did have the students hand the LTs in and (lightly) graded them--altogether the LTs contributed 5% to the final grade. I also was more careful to include follow-up think-pair-share questions after the LTs and at the start of lectures to reinforce material covered in the LTs... and finally, because I didn't do as many in class as I would've liked, I wound up assigning a handful as part of homeworks, which I know goes against the way they are intended to be used but felt better than not doing them at all.

The larger change involved exams. I added a second midterm, which allowed me to move the first one up. The idea there was to give students earlier exposure to exam material--and feedback on their exam performance--than in past semesters. The more exciting change, from my perspective, was to modify the exam format so that students did it first on their own (in the case of the midterm, for 50 min), handed in that version, and then did it again with a partner (for 30 min). If they scored higher on the solo exam they kept that score; if they scored higher on the joint exam (which is what one would hope!), the scores from the two exams were averaged to determine their midterm score. I was very nervous about trying this, among other reasons because of the need to have an even number of students(!). But I'm glad I did: it is a great way of reinforcing the idea that the group work exemplified by the think-pair-shares and the LTs is something I really value. (Like most of my teaching-related ideas, I stole this one from the Center for Astronomy Education's discussion group, astrolrner.) One practical note: next time I'll stick a sign on the door during the final--students kept wandering in thinking the exam was over, presumably because they could hear people talking...!

Earth, Moon, and Planets students visiting the Rare Book and Manuscript Library, April 2017. In the foreground to the right is a first edition of De revolutionibus orbium coelestium. To the left is one of Giovanni Schiaparelli's maps of Mars, showing the famous canals.

The final exam once again included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"This course has taught me the difference between a hypothesis, a model, and a theory. I'm able to understand that theories are not just ideas or personal opinions, but are rigorously tested and supported with evidence. I've also learned how much science changes as we gather more evidence. Often I think we look at science as absolute truth, but this course has taught me that as we gather new evidence, our understanding grows."

"Perhaps the most important thing this class taught me is this: Having the right answer is not nearly as important as asking the right questions. Because there is just so much mystery surrounding the galaxy, it also means there are so many unanswered questions."

"Yes--before this class, I thought of science as separate from my life. It was something that affected the world as I knew it, but not me specifically. Now, I feel like I have a better understanding of how science and the way the world has developed scientifically affect me personally (from greenhouse gases to the tides to the discoveries of Tycho Brahe). I didn't used to ever think about science unless I was in class. Now, I'll look at the night sky and know what phase the moon is in or why a planet is in retrograde."

"There was a poignant moment toward the end of the first half of the semester when a peer asked a "can you prove it wasn't aliens" question in which you replied "why can't we accept the possibility of human excellence?" For me, the optimism that science represents in the face of ignorance/unknown/lack of understanding is a deeply beautiful thing--something I had not been so keenly aware of in recent memory."

"Yes. Before this class, I saw the world as one giant mystery--it's [sic] formation, processes, relationship to the solar system and universe. Now, I have a basic understanding of how and why things happened in history and the present (pertaining to astronomy, of course). It's awesome to be able to look up and tell time with the moon, or know why the tides occur, or know how small we are, and so much more. I now see the importance and intrigue of science, as a very non-sciency person."

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Fall 2016: Astronomy UN3101: Modern Stellar Astrophysics

My third time teaching this class. I tried to incorporate things that had worked the last time (including having the students present on Annual Review articles and giving an oral final) but also included a traditional midterm, gave five problem sets rather than four, and did more in-class group exercises to assess learning and clarify difficult points.

The feedback was very positive, with some grousing about the midterm being too difficult and the homeworks not necessarily mirroring the lecture material (both fair points). Sample responses to the course evaluation question below--the second one is very long, but its a nice summary of all the things I tried to do...!
"Most of all, I learned critical thinking and problem solving. This class helped me better learn how to solve problems by using assumptions and estimations and learn when those are appropriate."

"I really liked the presentations that we had to do (and it definitely beat having another written midterm!). The presentations were engaging and I think they definitely enriched my understanding of related material that wasn't your run of the mill coursework. The problem sets were tough and time-consuming, so I'm glad they were only every other week (roughly). The midterm exam was fairly difficult and a formula sheet would have been useful, but I think it was definitely beneficial when we redid the questions that caused the most trouble from the exam in class. I also think the idea of an oral final was very good and in all honesty, quite fun. Like with the presentations, I enjoyed being able to read about a topic not necessarily contained within the bounds of the course (although definitely related). I think the presentations were beneficial not only because they were a sort of breath of fresh air in the monotonous cycle of problem sets and midterms that defines the life of astronomy and physics majors, but I also believe that it helps develop certain skills that are necessary for a career in science. Skills such as presentation in front of your peers and being able to explain scientific concepts concisely and effectively is critical for any aspiring physicist or astronomer and I'm very glad that assignments meant to develop those skills were included in the course."

In terms of my teaching style, the responses were again very positive, with one complaint about my lack of fixed office hours (I've never found those to work especially well anyway, but they seemed particularly unnecessary with a class this size) and one about the pressure that coming up with questions for the exit polls creates. Not too sure what to do about the latter point, particularly since many students pointed to the exit polls as one of the best things about the class:
"He is very easy to talk to and is very committed to giving students as much information as possible on the topics that interest them. I think this is best evidenced through the "exit polls" that he requires at the end of every class where students submit questions to him that they struck them during the lecture but wouldn't necessarily be on-topic enough to ask during class time. He always provides very thorough responses and is genuinely invested in explaining the answer to the student."

"Great instructor. He's friendly, always available, and obviously cares about what he teaches. He's also a good lecturer, and works through the examples and equations from his powerpoint slides. He helped us work through problems from graded work a couple times to make sure that we understood what was going on. Professor Agueros wants to make sure we understood what we were doing. Also, he had us submit questions to him after every lecture. I've never had a professor that was so engaged with the class. I hope I can take a class with him again."

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Spring 2016: Astronomy W1836: Stars and Atoms

My first time teaching this class, which I structured to include more physics and less history-of-ideas than my Earth, Moon, and Planets class. This was also my first time trying to include lecture tutorials in class, which I think worked really well. I need to work on incorporating follow-up to the tutorials (they don't come with answer keys, which some students find frustrating), but I really liked how they engaged the students, reinforced concepts, and broke up the lectures. Halfway through the class, I also experimented with voting on think-pair-share questions, which worked relatively well. The one mystery is what happened to my attendance--a quarter to a third of the class routinely missed lectures, which as far as I can recall was far more than in my more traditional lecture-format Earth, Moon, and Planets classes. Go figure.

Stars and Atoms students practice using their hands to measure angular sizes, February 2016. In the front row is my TA for the class, Alex Teachey.

The final exam once again included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"[...] this class has made me more inclined to think of the more collaborative, data driven, and to some extent mundane aspects of science. There is little glamor [sic] in making hundreds of parallax measures late at night for years in a row. Similarly, rarely do we sing the praises of someone who fruitlessly scanned hundreds of galaxies looking for the faint brightening of a distant supernova. Now however I am much more inclined to give thanks to such figures for our understanding of our place in the universe."

"This class reminded me that 1. I am quite insignificant and 2. Statistically, the odds of me being able to exist at this moment is so incredibly slim, so I am grateful for the opportunity I have to live (even if part of it was spent toiling over an intro level astronomy course). Thank you."

This was my first taste of the new course evaluations, which generally seem like an improvement (fewer Likert scale questions, more short answer ones). Overall the reviews were very good, with a few notable dissenting voices:
"I thought the course was a good intro to astronomy. I'd never taken an astronomy course before, and the course started off simple enough to understand for someone with nearly no astronomy background, and now I feel I can participate in a conversation about the topics that were taught."

"Marcel was incredible. His casual nature made a potentially intimidating topic interesting. His willingness to discuss other topics that pertained to astronomy but not necessarily the class made it special. Also, his ability to make a lecture feel like a small class was really nice."

"I absolutely loved Professor Agueros. His teaching style was incredible and very open. I never felt like I didn't understand what was going on. In addition, he made the class very interactive which was great in order to get out of powerpoint. If the class he is teaching next semester didn't have pre-reqs I would've easily took it."

Now, the dissenters (of which there were only a couple):
"Dud of a class. [...] The lecture tutorials especially were not helpful. We were given way too much time to work on them and they felt more like something that should have been assigned for outside class. That way I could have worked on them when I needed more practice on a topic and skipped the ones for the topics I understood."

"Not a good professor. He is not very approachable or good at lecturing. His lectures (including slides) could be much more concise. He seems bored teaching this class which in turn makes me feel bored attending class. He also could balance the time alloted [sic] to each topic better. Easy stuff (pretty much the whole first half of the semester) should have only taken 3 or 4 weeks and everything else could have been given more time."

I won't comment on whether I'm approachable or good at lecturing, but I think the criticism of the Lecture Tutorials is worth considering, as is the balance between the first half of the class (which is mainly introductory physics) and the second half (stellar evolution).

The other big complaint was about the in-class quizzes: I gave two, each of which was worth a quarter of a homework, so that together they accounted for 4% of the overall grade. The lesson here: never say that attendance is not mandatory, because apparently that's interpreted to mean "I don't need to come at all."

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Spring 2015: Astronomy W1403: Earth, Moon, and Planets

My third time teaching this class. Forty students, which I liked; more homeworks than in the past, which I think helped with exam preparation. Failed to get to the gas giants, yet again, never mind exoplanets...

The final exam once again included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers:
"It has enormously changed my perspective of the history of science, and subsequently improved my esteem for the human race. It makes a big difference to be told how our predecessors arrived at these conclusions that we take so much for granted now, rather than simply to hear that they did. We have produced many clever, commendable, eccentric, and above all enthusiastic people. I will remember that."

"[...] I was lying down on the lawn a few nights ago with some of my friends and started to explain how small we are and how the universe is structured. It was (at least from what I can remember) the first time I'd ever incorporated science into my conversation with confidence."

"[...] I now try to think of a cause for most natural things I encounter. Science has peaked my curiosity in how things work and this course has been a guiding force in increasing my curiosity and interest in the inner workings of our natural and man-made surroundings."

Sample comments from the class evaluations, in response to "What were the best aspects of this course?":
"Professor Agueros puts in a lot of effort and that is clear to the students. By doing so he sets the tone for a serious course that is not typical of science for non-science major courses."

"I liked a lot of the quirky little asides. Also the exit polls are a nice way to get a sense of what we were thinking about the material and I liked that you always addressed them."

"Provides an environment for students to think through a topic. The information is not simply handed to us and memorized. Prof. Agueros' enthusiasm inspires interest for science."

And in response to "Would you recommend this class to a friend?" (no one answered "no"):
"I would. It would help make him more mindful of misconceptions about astronomy, and would be surprisingly helpful for developing hobby interests in stargazing (when not in New York, at least). It also gives one an appreciation for - well - how precarious our existence is in the grand scheme of things."

"Yes, I'd recommend. Lectures were delivered clearly and I felt like there was a great effort at getting feedback/questions from students."

The most negative comment was probably that the exams were "gruesome," which I loved as a description, if not as an experience for the student in question!

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Fall 2014: Astronomy C3101: Modern Stellar Astrophysics

My second time teaching this class. I had eight students, which freed me to try a few different things: for one, there was no midterm; instead, each student had to prepare a 20-25 min presentation on an Annual Review of Astronomy and Astrophysics article related to stellar astrophysics (topics ranged from solar neutrinos to stellar multiplicity to short-duration gamma-ray bursts). For another, the final was a half-hour oral exam during which each student answered my questions about another Annual Review article, on the impact of mass-loss on the evolution of high-mass stars. I still think the course content could be better structured, and I definitely did not use the textbook (which was supposed to be Carroll & Ostlie), but overall it went pretty well. Only four students filled out the evaluation, so take the following with a grain of salt.

Sample comments from the evaluations for this class:
"Professor Agueros was phenomenal. He was a great lecturer and really helped us understand the course material to his fullest extent. Additionally, he really paid attention to student input with the exit polls and incorporated answers into the start of the next class, which I thought was really neat and something none of my other professors would ever do."

"The assignments were very reasonable in that I felt I could tackle them while still being challenged. Sometimes phrasing could be a little unclear as to where the solution of the problem should go, but this was minor. I really liked the presentation format of the midterm. Making the presentation helped me organize and therefore better understand my annual review, much more than I think a written exam that I studied a lot for would have."

"It was so damn interesting. I learned so much and I felt like every lecture I walked away understanding something I didn't know about before class. That feeling is irreplaceable and quite honestly something I don't think I've gotten out of any other class at Columbia."

"Best astronomy or physics professor I've had! It was sometimes stressful to have the daily exit polls and to come up with questions every time, but it was a great way to structure the class and for us to actually get to ask questions we're curious about. And the exit polls would be answered very well each time, and was a way for us to structure lecture on what we wanted to learn more about."

Maybe the most surprising evaluation ever:
"I actually would have liked more homework. The six we were supposed to have instead of the four we did would have been nice. I always got a good diagnostic of what I didn't have a good understanding of and was able to then learn a lot doing the homework."

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Spring 2014: Astronomy G9004: Research Seminar

The biggest change relative to other times I have taught this class was that I required that everyone write and submit a MDM proposal, and that we then went through the exercise of convening a mock time-allocation committee (which included Jules Halpern, who does the actual time allocation for MDM) to assess these proposals. I didn't get that many comments in the evaluations, but here are a couple:
"Compared to other semesters, where the professor talked most of the time or one or two students did big presentations, I liked that we all got to participate in discussion/workshopping every week, and learned about topics (like review boards and conflicts of interest) that we may not have come across until the post-doc stage."

"I would characterize this semester as being focused on the professional development side of research, since we talked about ethics, how to write proposals, how to give good talks, etc. In comparison to last semester, I am walking away with much more concrete / readily applicable skills. And as much as we bemoaned having to do the observational proposal, it did end up being a positive experience. [...] The only thing I would change about the course is to reduce the amount of time spent on the ethics discussion. Though it was useful and interesting, I felt we spent too long (5 weeks I think?). Maybe 2-3 classes discussing ethics at most. With the extra time, maybe spend time discussing the process of writing grant proposals, code sharing (which I know was planned, but fell through), or how to properly network."

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Spring 2013: Astronomy C3101: Modern Stellar Astrophysics

My first time teaching a class for majors. I thought that the class pitched at too high a level, and I was somewhat surprised that the course reviews were uniformly positive (on the other hand, only a third of the class filled them out). One thing that did work well was to bring in various guests to discuss current research related to topics we touched on in class. After I talked about the solar neutrino problem, for example, I got enough interest that I decided to invite a graduate student from physics to discuss current neutrino detection experiments. Another thing I did was to not only collect but also answer the exit polls (the one-minute essays I have students fill out at the end of each lecture). I was able to be responsive to concerns and also identify areas (such as neutrino research!) that students were interested in learning more about.

Sample comments from the evaluations for this class:
"I enjoyed whenever we saw cutting edge research and stuff in class. It really brings out the emerging nature of astrophysics knowledge."

"The exit polls were great--both for getting answers to questions, and stimulating deeper thought about the subject."

"I found most course materials interesting. This was my first astro course, so I was always being introduced to new concepts taught and discussed in class. The best part was that I got a decent sense of what astrophysicists know and don't know today."

"Prof. Agueros was one of the best teachers I've had at Columbia over the last four years. It was great that his slides were detailed and thorough, because it made reviewing much easier. Some students were complaining that the slides had too many details and were hard to read during class, but in my opinion, difficult course materials are learned mostly during review anyway, so lots of details were helpful."

The negatives:
"I wish the grading process was explained at the beginning of the semester. It was definitely harder than in previous courses in the department, and as this differs professor to professor it would be helpful to know what the professor is looking for in exams and homework. Also more direction on what to focus on for exams would have been helpful, even just a list of what we are expected to know by the end of the course."

"I was not a huge fan of the exit polls, although they do allow for greater teacher-student interaction."

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Fall 2012: Astronomy C1403: Earth, Moon, and Planets

My second time around teaching this class and it was, if nothing else, more coherent than the first time (phew!). The final exam included the bonus question "Has this class changed the way you think about science?" Any answer was worth a few points, an idea I stole from Doug Duncan.

Some of my favorite answers (hard to choose; there were lots of great ones):
"[...] I generally derived my sense of how difficult a science was by how much math was involved. What I've garnered from this course is that science doesn't always have to involve numbers; the concepts, theories, principles and over all ideas in much of what I've learned about astronomy are just as, if not more complex and scientific as any lengthy mathematical equation."

"[...] I'm used to being given formulas and plugging and chugging numbers. I've never really liked science because I never understand the concepts behind what we're doing. I enjoyed this class though because it was different and because I can use what I learned in other classes. I learned that science can help you develop your ability to analyze, if it is taught well."

"[...] I will never again let someone win the argument by saying, "It's just a theory.""

"This class changed the way I think about science by putting the facts and theories in the context of a long-running historical dialog among many great thinkers and observers. I wish other science classes would do the same, as it really humanizes the subject matter, makes it more accessible, and inspires me to learn more independently."

"Science isn't about reducing the beauty of the universe into cold, hard facts and figures. It's about exploring and celebrating the magic behind the workings of the world. Science isn't about knowledge. It's about continuing to be filled with wonder and awe at the natural phenomena we observe every day. Science is poetry."

Sample comments from the class evaluations, in response to "What were the best aspects of this course?":
"Hands-down the "trip" to the rare manuscript library to see (AND HOLD!) 1st edition Galileo, Newton and Copernicus books! What an amazing (once in a lifetime) experience."

"I really enjoyed the historical discussions, including the lecture about the space race and the discussion of the specific Mars rover missions and what each one individually accomplished."

A couple of comments highlighted an issue that I was pretty sure would come up when I decided to get rid of the quizzes (which the 2010 group despised):
"When it comes to preparing for the exams, be more clear about what is important for us to understand."

"I felt unprepared for the midterm. We had covered a great deal of material, and I felt that we weren't made aware of what in particular we needed to know and practice in depth."

So that's something I'll need to revisit next time around (Spring 2014??)...

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Spring 2012: Astronomy G9002: Graduate Seminar
High-Impact Papers in Astronomy & Astrophysics

Zoltán Haiman and I co-taught this class, which had two goals: to read, discuss, and understand high-impact papers in astronomy across a range of sub-fields, and to examine how and why particular papers have high impact. It was also intended to develop presentation and classroom-discussion skills. We struggled a bit to get the right balance between presentation and discussion, and some papers proved to be more motivating than others. But overall I thought it went pretty well.

Sample comments from the evaluations for this class:
"I wish we had focused more on classic papers. About half-way through the semester the class veered more towards reviewing large topics in astronomy. ("Putting it in context" turned into "reviewing the related astronomy".) I preferred discussing the physics of 1-2 seminal papers each week."

"I enjoyed and benefited from the first half of the semester much more than the second half of the semester, both as a presenter and an attendee. In the first half it seemed that very interesting and relevant papers were suggested and thus the discussion was always pertinent to those papers. In the second half it felt like we were just trying to touch on various topics (e.g. jets, asteroseismology, exoplanets)."

Definitely fair criticisms and something we will have to work on for the next time around...

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Fall 2011: Astronomy G9003: Research Seminar

I decided to have this class focus on the Astro2010 Decadal Survey. It was yet another experiment and I think it was semi-successful. I certainly learned a lot, but it was not always easy to generate good discussions, and sometimes the class felt rushed.

Sample comments from the evaluations for this class:
"I thought the class was really helpful in presenting an aspect of the profession that you only learn about from people who have been around longer. I'm finding that there are many things you learn in grad school by having the information passed down from older students and advisors. Picking a major topic (decadal survey; submitting a paper; research proposals, etc) like this for each semester might be a good format for the research seminar in the future."

on the other hand:

"The annual [sic] report was fun to dissect, but I wonder if it was the very best use of everyone's time."

So some mixed feelings about the usefulness of this class. Throw in some very different opinions about what the best use of research seminar is (both in this set of evaluations and in those from Spring 2011), and it's clear that the debate about this class is nowhere near over!

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Spring 2011: Astronomy G9004: Research Seminar

A few articles of interest, possibly, for discussions of graduate student professional development:

Sample comments:
"I really appreciate that you made the class less about the research that we're specifically doing (I think our advisors are best to discuss this with) and more about research skills in general."

"I really liked how the course focused on how to present your research to others. It helped us become better researchers without us just going around and talking about what we did that week. Perhaps a way to enforce this next semester would be to make a few people each meeting give a pizza-lunch type presentation just so we keep practicing giving presentations."

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Fall 2010: Astronomy C1403: Earth, Moon, and Planets

Thanks to Mahmoud Samori for pointing out the following review of my class from CULPA, which I'd never heard of (and which no longer exists, as we have gone through a number of changes to the way student evaluations are collected and shared...!):
"Marcel is a great professor, his lectures are super funny and are always enjoyable to go to, I highly recommend him if you actually want to learn about astronomy. He seems very interested in 2012 and the end of the world. There are only 4 homework assignments which are pretty easy. His quizzes are pretty tough if you don't go to lectures or study. You need to read everything from the book. The midterm and final were quite easy as long you put the work in to study. He is a really nice guy and he is always available to answer questions, and his sense of humor is great. This class isn't easy, but at the end of the course you actually feel like you learned something useful."

One telling quote from another CULPA review:
"In terms of the class itself, the topics covered are just enough to give you a good understanding of the universe, physics, and ratios/scales. Anyone can understand it if you pay attention. Yes, the quizes [sic] can sometimes throw you for a loop because he expects you not only to know the material from the text and lectures but also how to apply them in other ways--taking the formulas and laws and using them to explain astronomical happenings in your own words, essentially."

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