The Scent of Information

I’d been thinking about open educational resources (OER) and how students might “learn” from the World Wide Web. In my non-majors chemistry course this semester, I chose not to assign a textbook as part of an OER initiative. Instead I assign reading from a couple of online texts plus a few other resources here and there. But do the students read these resources? My quizzes suggest that many of them do not, or they don’t understand what they’re reading even though I’ve picked what seems to me relatively straightforward information.

My very knowledgeable wife sent me an interesting article about how folks browse the Internet for information. It’s an old article (from 2003), but well-written and insightful. The title is “Information Foraging: Why Google Makes People Leave Your Site Faster”. The main concept is information scent. Here’s how the authors describe it: “Users estimate a given hunt’s likely success from the spoor: assessing whether their path exhibits cues related to the desired outcome. Informavores will keep clicking as long as they sense (to mix metaphors) that they're "getting warmer" – the scent must keep getting stronger and stronger, or people give up. Progress must seem rapid enough to be worth the predicted effort required to reach the destination.”

In the early years, when search algorithms were still in their infancy, the vast majority of websites you might come across were not of the highest quality. So once you found one, the best strategy was to stick with it; moving on would likely yield less desirable results. Thus, the rationale behind designing a website to attract readers was to make the sites “sticky” by having the initial scent of good content lead to more good content. Hungry users follow the scent!

However thanks to powerful search engines like Google and its contemporary cousins, the ease of finding “good” websites has increased significantly. The downside is that it leads to information snacking, brief visits where the scent leads a tasty morsel, and then departing to find a different morsel elsewhere. Instead of the all-in-one banquet, the modern “informavore” prefers the progressive tapas dinner across multiple locations. In this case, traveling between locations is at the speed of lightning. This leads to different strategies in website design.

What does this have to do with OER? I’ve been mulling over what a good strategy might be for self-paced learning via OER. Not just superficial learning of a factoid here and there, but deep learning that is coherent and indeed leverages the connectivity of the Internet of today and tomorrow. Does one go immersive in a web-based World-of-Warcraft type system? Or is there some other way to curate from the best but somehow have the user/learner directed in such a way that maximum learning, perhaps even mastery learning, takes place. It needs to be attractive enough so that someone who catches the scent is motivated to keep going. But it’s unclear what indeed is the best scent to incentivize learning.

Thinking about this reminds me that I really need to take some time to ponder the deep structure of chemistry in the context of curriculum design. One thing I’m enjoying with my OER approach is a large degree of freedom in re-organizing the material in a way that I hope promotes the scaffolding of deep structure. While few of the students in my non-majors class will go on to take other chemistry classes at least as college students, but if I can instill enough of a scent, maybe they will pursue learning some more on their own later in life. Maybe that’s wishful thinking, but the small dose of idealism helps keep me going. So far I haven’t made large-scale changes, perhaps from too many years of hewing to a standard curricular approach. But Spring Break is coming up, and I’m motivated to think about this issue more carefully!

(I’ve also been tweaking my science-majors chemistry course, and perhaps that is where it is even more important to implant deep structure.)

Teaching, Research and Scholarship, Part 5

Four weeks ago, a Brookings report caught my eye while I was websurfing. “Are great teachers poor scholars?” by David Figlio and Morton Schapiro focuses this question on their own campus, Northwestern University. Here’s a link to the report. Since the release of the report coincided with my early semester busyness, I didn’t get around to blogging about it. So a month later, here are a summary of the results and my subsequent thoughts.

The authors used two proxies to measure teaching quality: (1) The percentage of students that declared a major in an area after taking a first-quarter course in that same field is the “conversion” rate. The authors refer to this an indicator of inspiration due to the first-quarter instructor. (2) The effect of students’ future grades in subsequent classes in the same major field reflects the longer-term value provided by the first-quarter instructor. The authors refer to this as an indicator of deep learning. The data was crunched for eight cohorts of first-year undergraduates.

Research was measured in two ways: (1) Northwestern annually recognizes and honors a subset of its faculty for “research excellence”. Criteria include being elected into prestigious academic organizations, receiving prestigious fellowships, winning major research awards, and more. (2) The h-index was computed for faculty members scaled to departments since there is a large variation in citation norms across different disciplines.

Perhaps not surprisingly, the two research measures correlated. On the other hand, there is essentially no correlation between the two teaching measures, i.e., an instructor who had inspired many students choose to major in that field may or may not have provided them with deep learning. And those who seem to have provided deeper learning, may or may not show much in the way of inspiration. Without more details and the raw data, the lack of correlation is unclear. Furthermore, whether the teaching proxies are reasonable indicators of inspiration, deep learning, or even teaching effectiveness is questionable. The authors do suggest the possibility that their proxies are ineffective measures, but clearly they think there is something to their results, otherwise it likely would not have been published.

Are these results unique to Northwestern? The participants are only tenured faculty, thereby narrowing the pool to those who are at least successful enough on both fronts to earn tenure. As an R1 institution, the teaching loads at Northwestern are also lower on average. With a heavier teaching load, the time constraints may start to impact quality. If you’re at a liberal arts college, with no graduate students, the time factor is even more acute. You don’t have teaching assistants to help with the grading, although this is balanced by having smaller sections. If you’re a lab scientist, your group’s productivity isn’t going to be as high unless you as the principal investigator put in a substantial amount of time training and working with your undergraduate research students. This is balanced by lower productivity research requirements compared to R1 institutions, at least in terms of quantity, not quality.

The report questions the motivation of the University of California system’s move to security-of-employment lecturers, effectively a tenure-line teaching track. The authors think that “protecting the time of the research faculty” may not be an adequate argument. Perhaps Northwestern has more resources, but from a resource point of view, especially with burgeoning numbers of students flocking to the sciences (at least at the introductory level), adjunctification of faculty is simply going to increase. Providing security-of-employment and retaining top-notch teachers who choose to devote their career to full-time teaching excellence seems to me a good thing.

The authors state that “the reason why most of the top-rated universities in the world are located in the United States is not what goes on in its classrooms; it is the research power of its faculties.” And furthermore, “faculty salaries at research universities are determined primarily by research performance and the reputation that comes with it.” I appreciate the fact that having a diversity of educational institutions in the United States allows serving a diverse population with diverse needs. I chose being at a liberal arts college because while I think research and advancing knowledge for its own sake it is important, research is an excellent activity contributing to the education of college undergraduates. But productivity isn’t the main goal, education is! I think it sad that the marketplace places the R1 star researcher at the top of an academic hierarchy, often allowing such people to negotiate lower teaching loads or avoid introductory undergraduate courses. Not all institutions do these, and perhaps Northwestern falls into that category, but as competition continues to heat up, human beings have only 24 hours per day, some of which needs to be spent sleeping or recuperating. It’s hard to achieve excellence in multiple areas without putting in the time and having the appropriate supporting resources. Something will have to give.

(Links to previous posts on this series: part 4, part 3, part 2, part 1)

No Magical Index?

This month's guest blog post, from a chemist and librarian. Enjoy!

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While on vacation last summer, on a whim, I started re-reading the Harry Potter books. All the Harry Potter books. In 10 days (I think). I know there are other things I could have been doing, but this was certainly very enjoyable.

While reading Book 1, my reflex response to Harry, Ron, and Hermione poring over books in the library to find Nicholas Flamel, was, why don't they just Google him? Okay, yes, I should know better. Electronics don't work in the magical world. But old habits die hard.

Further consideration of this problem made me think about why there is no mention of index system for spells and potions. In Book 2, when the trio wants to make Polyjuice potion, they only know about its existence and where to find it because Snape tells them what book it's in.

This got me to thinking about the days before SciFinder, when we used the never-ending volumes of Chemical Abstracts in print. In our current era of structure and keyword searching, the method seems very archaic. Although time consuming, it was very practical and straightforward. You calculate the chemical formula for the compound of interest. Then you check each 10-year index, looking for any references to your compound of interest. Nomenclature has always been my weak point, so I often had trouble identifying the IUPAC names. It was a slow and laborious process. But it worked!

(Photo source: https://flic.kr/p/8bLry1)

So why is there no similar system of indexing in the magical world? The Half-blood Prince and Luna's mother present evidence that there was experimentation among witches and wizards. Professor Umbridge was adamant about "Ministry-approved methods", all of which imply that there were more magical spells and potions available than what students were taught in school.

I wondered if perhaps there was just a culture of secrecy, and the wizarding world didn't want to share new discoveries. But the Harry Potter wiki lists three scholarly journals mentioned in the HP books: Transfiguration Today, The Practical Potioneer, and Challenges in Charming. Their existence suggests that at least some witches and wizards wanted the world to know what they had accomplished.

Would it be too difficult to create and maintain this kind of an index? Seems unlikely, I mean, even Muggles can do it.

This led me to consider that the creative process involved in discovering new spells and potions is not well developed in the books. Professor Slughorn mentions it briefly in Book 6. On the day that most of Harry's potions class is taking their Apparition tests, Slughorn, speaking of Harry's Euphoria potion: "… you've added just a sprig of peppermint, haven't you? Unorthodox, but what a stroke of inspiration…" In the same class, "[Ernie] had most rashly invented his own potion, which had curdled and formed a kind of purple dumpling at the bottom of his cauldron."

There are many examples of spells and potions gone awry due to poor technique; far fewer instances of improvisation and creating new magic, with the exception of dark magic. Perhaps because of Tom Riddle's foray into new magic was incredibly disastrous for the wizarding community, it seemed safer to stick with what is known and "Ministry-approved".

I still don't have a good answer to why there is no magical index in the wizarding world. Perhaps they didn't want to make it too easy for those inexperienced in magic to inadvertently hurt themselves and others, lest it lead to another "Magic is Might" movement. As Dumbledore says: “Dark times lie ahead of us and there will be a time when we must choose between what is easy and what is right.”

Robots and the Liberal Arts

Last week, I read an article in the Chronicle of Higher Education with the provocative title “How Robots Will Save Liberal Education”. The author, Eboo Patel, is a Rhodes scholar, trained in sociology, and he served on Obama’s advisory council on faith-based neighborhood partnerships. The essay begins with a vignette of the author’s mother trying to persuade him as an undergraduate to major in business for job security reasons. She viewed his intended sociology major as being a luxury, but perhaps not very useful. Twenty years later, it’s clear that Patel has put his training to good use, in an entrepreneurial way no less.

Patel argues that the “hallmarks of a liberal education – building an ethical foundation that values the well-being of others, strengthening the mental muscles that allow you to acquire new knowledge quickly, and developing the skills to apply it effectively in rapidly shifting contexts – are not luxuries but necessities for preparing professionals for the coming transformation of knowledge work to relationship work.” Certainly these are all good outcomes of higher education, but it isn’t clear that they are provided only by a liberal education, and that business and engineering majors, would lack these skills without the appropriate classes, or in particular pedagogical method.

He speculates “that the 15-student seminar discussing Plato’s relevance to contemporary situations [could turn out] to be better preparation for the jobs of the future than working through problem sets alone for a science or engineering class.” He posits that the seminar requires attentiveness to diverse viewpoints, working on a synthesis of multiple viewpoints, constructing and communicating an argument, and iterate through this process to make stronger arguments. “All of the above happens in the space of a few minutes in an actual room with actual people. The problem set can be done in a split second by a computer.”

But careful thinking, iterative processing, and synthesizing information from multiple sources isn’t limited to the philosophy seminar (or other liberal arts courses in the humanities and social sciences). This is what scientists and engineers are trained to do in their education; they might even get more rigorous training. Now as a scientist in a liberal arts setting, I think our science majors potentially get the best of both worlds – while the paucity of science requirements for non-science majors does them a major disservice. While I understand that Patel may highlight a stereotypical distinction to make a point, his pedagogic argument is confused, perhaps because he has less teaching experience in the college classroom. Yes, having students discuss and make supporting arguments is good, but only if they have done the reading and thought about it on their own to some extent and wrestled with it. Only then is the dialectic in the classroom enhancing. And the purpose of a problem set isn’t to solve the problem with a known answer. It requires the students to wrestle with, think about, and provides them with the foundation to then do something else more complicated. It’s a crucial part of the learning process. My students also work in groups and we do have class-wide discussions, but part of the “alone” time working on the problem is key to learning – I’m sure this is true broadly across disciplines and not just in the sciences.

Where I do agree with Patel is that teaching and learning is best in a relational context. They should not be divorced to learning in a disembodied content. This is true not just for human learning, but also from observations of animal learning. (I recently finished Frank De Waal’s Are We Smart Enough to Know How Smart Animals are?) The social aspects may be even more important in the ape culture where technology is more limited, and the relationships are nuanced and complex. Technology allows us to rely less on human relationships to some extent, although it can also enhance relationships across space and time that would have been more difficult to do without writing, movable type, the computer and the internet.

Patel concludes that “robots may well perform medical operations and process our financial transactions in the not-too-distant future, but they are unlikely to replace pastors in pulpits, teachers in classrooms, nurses in hospitals, or coaches on the basketball court.” I’m not so sure, particularly with regard to the notion of place. I think there will still be pastors, teachers, nurses and coaches. But they may not exist in physical or localized pulpits, classrooms, hospitals or gyms. I agree with Patel that “people need interaction with other people to become better people”, and that liberal education, broadly construed, helps. But what if that’s not the goal of the people? The ideal society envisioned by Plato’s philosopher kings may not be shared by its democratic populace. Robots, part of the technological advance, raise particular questions about relationship and identity. Are we increasingly choosing to be Alone Together? And if so, perhaps liberal education is truly in jeopardy.

Potions and Poisons

In my non-majors class this semester, students will design a magical potion of their choice using chemical principles. This is a “theoretical” design because my class does not have a lab component, and I’m not sure I want them extracting and mixing a bunch of chemicals that vary in their hazard-ness. The students will write this up as part of a textbook chapter and work in small groups. The assignment makes up 20% of the course grade. For quality control purposes, and also to ease student anxiety about “out-of-the-box” assignments, my goal is to provide an example of what I’m looking for.

Over winter break, I mulled over the idea of choosing something whimsical that the students would not have thought of, and therefore unlikely to choose as their “potion of interest”. (I was planning to poll the students sometime in week 4 or 5 to gather a list of their potions of interest.) The first idea was a joke potion that would make your voice change at parties if someone slipped it into your drink. The active ingredient would be nitrous oxide (N₂O) but it would have to be appropriately “packaged” so that the chemical delivery happens at the right time – when the intended “victim” takes a beverage sip. A tiny capsule would be too obvious in a clear drink. But if you had a solid package or powder that dissolved too quickly, the N₂O would just bubble out of the beverage before the drink was consumed. I had a few ideas of some fancy liquid-soluble cavitands, but I would be making some complicated chemical leaps that may be rather challenging for the students.

So this weekend I started reading The Poisoner’s Handbook by Deborah Blum. Each chapter discusses a particular chemical substance used as a poison during the Jazz Age in New York. While there is some chemistry in the book, it is more interesting as a history and sign of the times. I learned many interesting factoids about how one sets up a toxicology lab and the types of analyses one could do a century ago, when we did not know as much chemistry as we do today. (There’s lots of trial and error. Not to mention court trials and errors in judgment!) A couple of days ago I read the chapter on wood alcohol, CH₃OH, sometimes called methyl alcohol (from the Greek words meaning wine and wood) or methanol (following IUPAC convention). With the backdrop of prohibition, wood alcohol was a popular cheap moonshine – even though it caused blindness, nausea, dizziness and death.

Grain alcohol, C₂H₅OH (ethanol), or ethyl alcohol is safer to consume because the biochemical pathways result in different chemical substances produced. In the case of methanol however, two of the problem-causing products in particular are formaldehyde (featured in my previous post!) and formic acid. I also read the chapter just in time for my General Chemistry class yesterday when we talked about fuels. After calculating the energy efficiency of hydrocarbons, we looked at compounds containing oxygen and nitrogen; methanol was one of the main examples used to illustrate the challenges in thinking about alternative fuels. (I worked on direct methanol fuel cells and partial methane oxidation many moons ago.) And I was able to appropriately warn my students not to consume methanol! (There was nervous laughter in class.)

Yesterday night I read the chapter on cyanides. Upon reading the symptoms of cyanide poisoning, I was immediately reminded of Harry Potter and the Half-Blood Prince where Ron gets temporarily poisoned when consuming a fine alcoholic beverage, ironically just after he has been given an antidote for a love potion gone awry. (I admit to having immediately cracking open Book 6 and reading the appropriate section to confirm the similarity in Ron’s symptoms.) Unlike a love potion that targets a specific individual, presumably through an ingredient that is pheromone-related, no “magic” ingredient was needed for the poison. One wonders if the poisoner knew something about chemistry to extract the appropriate cyanide compounds (there are many sources) and spike the drink. Professor Slughorn is too shocked to mix up an antidote, but quick-thinking Harry manages to save Ron with a bezoar. Given how fast cyanide acts, mixing up an antidote might have taken too long anyway.

Could one design a potion as an antidote for cyanide poisoning? Cyanide essentially acts by replacing oxygen in hemoglobin (the carrier of oxygen). So essentially you can’t “breathe”, your cells get deprived of oxygen, and then all sorts of nasty things happen metabolically. Hence, there are two general approaches to an antidote: (1) One could flush someone with a high dose of oxygen in an attempt to swamp out the cyanide. (2) One could add a substance that scavenges the cyanide away from hemoglobin, i.e., trapping the cyanide. Anything that you add must not cause more problems than it solves. A high dosage of oxygen can be potentially dangerous if not administered carefully. There are many other substances that can trap cyanide, but not many that you should consume. One possibility is hydroxocobalamin found in Vitamin B12. This molecule has some structural similarities to hemoglobin, notably the presence of a porphyrin ring surrounding a metal center. In hemoglobin, the metal is iron; in hydroxocobalamin it is cobalt. Cyanide binds to the metal ion.

I haven’t done the research to look at other possible substances, but it may be that a cocktail of substances mixed together could provide several ways to either displace cyanide from hogging the hemoglobin. Extracting these chemicals from natural sources (since that’s what Potions is about) both magical and non-magical and mixing them together in the right amounts could produce a suitable antidote potion. Vitamin B12 is found mainly in meat, eggs and dairy. Maybe there is a magical creature that has a related vitamin and therefore a slightly modified version of hydroxocobalamin that is particularly good at removing cyanide. (I also want my students to exercise some creativity and imagination.) The concoction might also contain some iron compounds that would form complexes with cyanide. For example, the “Prussian Blue” test to detect cyanide involves adding iron sulphate to a cyanide solution. Hopefully students would use chemical principles to think about how substances could be “modified” (creatively, of course) for the desired outcome.

Or maybe I could investigate the chemistry of a bezoar. Hmmm… so many interesting things to think about!

Cognitive Load in Learning Chemistry

Several things swirled in my mind the last couple of days culminating in the question. Does learning chemistry impose an additional cognitive load on students, perhaps even more so than the other sciences? Is there something unique about introductory level chemistry that requires special attention from us teachers in designing our learning activities?

I meet new people on occasion, and this past week, finding out that I teach chemistry led to a personal disclosure from my new acquaintance about how chemistry was hard and didn’t make sense in school. I don’t hear this as much about biology or physics, but that might just be a sampling effect due to my being a chemist. I’ve also been reading Reactions by Peter Atkins. It is beautifully illustrated with chemical substances at the molecular level on virtually every page. I did not find the prose as engaging, and I don’t personally recommend it if I wanted to get you excited about chemistry; Periodic Tales is much better. But one thing that Reactions does well is showing you lots of molecular level pictures. This “molecular view” is something my colleagues and I stress heavily in our introductory chemistry classes.

Why is the molecular view so important for chemists? That’s where all the action is! Chemistry is about making and breaking chemical bonds, a chaotic dance where atomic partners are swapped. But the problem is that we cannot see this frenetic molecular level activity with our own eyes. We see macroscopic changes such as bubbles, a color change, perhaps a spark of light, or glimpse the appearance or disappearance of a solid. As I’ve been thinking about cognitive load and the differences between how experts and novices learn and process new information, it’s perhaps worth taking a step back to see how one might view a chemical reaction.

Consider the hydration of formaldehyde to form methylene glycol. This is a reaction of interest to chemical engineers, atmospheric chemists, and those who study the chemistry of the origin-of-life such as myself. If I asked a student to write a chemical equation for this reaction, I might get CH₂O + H₂O --> CH₄O₂ from a student in an introductory chemistry class who knew the “chemical formulae” of each of these substances. A student in organic chemistry might write the product methylene glycol as CH₂(OH)₂ to represent something about how the atoms are connected in the molecule.

Thinking molecularly, one might imagine the reaction to look like:

A student in organic chemistry might “draw” the reaction as:

The carbonyl (C=O) bond of formaldehyde is emphasized since a key chemical reaction of carbonyls is to undergo “nucleophilic addition”. Methylene glycol is drawn as a “line structure” where carbons are not explicitly labeled and hydrogens attached to carbons are not shown.

A student thinking about how the reaction proceeds would consider what chemical bonds are broken in the reactants, and what bonds are being made when the product is formed. A simple representational drawing of the “transition state” as the midpoint within the chemical reaction is shown below. Dashed lines represent the bonds being “made and broken”. Also notice the C–H bonds that do not participate in the chemical reaction are drawn with wedges that show how the CH₂O and H₂O molecules approach each other in three-dimensional space for a productive reaction.

How does this reaction happen in practice? If you were an atmospheric chemist, volatile formaldehyde could dissolve in cloud droplets. You might therefore write the reaction as: CH₂O(g) + H₂O(l) --> CH₂(OH)₂(aq) with the phases of matter of each substance specified (g = gas, l = liquid, aq = aqueous, a solution of a substance dissolved in water). If you were measuring this reaction in a lab, it would never involve just two molecules colliding to form a new molecule. The formaldehyde molecule as it dissolves into water would encounter many water molecules. In fact there is likely to exist a different transition state where the presence of other water molecules assists (or catalyzes) the chemical reaction. Below is a different transition state that is much more likely to occur than the one previously shown because it is energetically more feasible. (Energy is the currency in chemical reactions!)

In fact, there are other transition states more complex than the one above that may be even more probable. (I know this because all my new research students from the last five years do a series of computations on this very reaction as their first test case.) Formaldehyde dissolving in water, viewed at the molecular level, is likely to look like just a lot of water! The water molecules are closely spaced as shown in the water “box” below. (Such boxes are a standard part of the simulator’s toolkit.) You’d be hard-pressed to find a formaldehyde molecule even in a relatively concentrated solution, such as a 1 M (or one molar) solution. In a 1 M solution, one mole of formaldehyde is dissolved in 1 L of water. That’s approximately 2 molecules of formaldehyde per 111 molecules of water.

When we teach students to write “balanced” chemical equations, and then calculate the amount of product formed given some amount of starting reactants, the chemical reactions are written in terms of the mole (6.022 x 10²³ molecules). So while on the one hand we want students to think of “balanced” chemical reactions at the molecular level (with molecular pictures in mind), we also want them to be able to think of these same reaction at the level of moles, or the macroscopic level. One mole of water, at18 mL in volume (or just over a tablespoon) is an amount you can physically observe.

As a chemistry professor (or the “expert”), shifting back and forth between the molecular level and the macroscopic level, not to mention thinking about all the different representations shown above, poses practically no cognitive load. All these ways of thinking about the reaction have become second nature, and my mind effortlessly moves to the representation I need for the problem at hand. But this is not true of the student (or the “novice”). The cognitive load can be substantial. One reason why the introductory college chemistry course is particularly challenging is that students enter college with highly varied backgrounds. The student who has taken Advanced Placement Chemistry is much more comfortable “shifting gears” than the students who has taken no chemistry, or barely understood any of it.

When I first conceived of a Potions for Muggles textbook, I thought it should be heavily illustrated with molecular pictures (like most popular chemistry textbooks today) because that’s how I think about chemistry as the expert. But I’m starting to see that an over-emphasis of the simple (and pretty) molecular pictures sometimes obscures understanding instead of illuminating it simply by imposing an additional cognitive load that a reader may not be ready for. The transition from novice to expert requires quickly identifying the key elements of a problem. Novices are awash in a sea of information and it’s hard to prioritize which representational view is going to help them tackle the issue at hand. I still think pictures are important but they should be chosen with care.

The formaldehyde hydration reaction is actually a bit more complicated because (1) it can go in reverse, and (2) formaldehyde can react with methylene glycol to form the C₂H₆O₃ molecule (HO-CH₂-O-CH₂-OH), depending on the relative amounts of formaldehyde and water. If one simply considered one molecule of formaldehyde and one molecule of water in a highly artificial system, then (1) is easy to deal with, and (2) is irrelevant. But in a real system involving moles of molecules, things could get much more complicated. For example, a third molecule of formaldehyde could add to the C₂H₆O₃  molecule, eliminate a water molecule in the process, and form the trioxane shown below.

Phew! Maybe that’s why people keep telling me chemistry is difficult. I spent my first two years of chemistry class without understanding some of the basics I just described above. Hopefully, I can help my students overcome the barrier and present the material systematically and with the right level of cognitive load.

First Week: Spring 2017 Edition

Looking back at my blog, I see that I have regularly posted about my first week of classes; at least I have done so the past three semesters. So without further ado, here is the Spring 2017 edition!

Having recently read Dylan Wiliam’s book, and giving my self two things to work in my teaching, I was very excited to make modifications to some of my class activities. I am teaching two classes this semester: (1) the honors section of second-semester general chemistry, and (2) a chemistry for non-science majors course themed around potions!

The honors general chemistry section is small, limited to 20 students this semester, partly because we are in a very tight classroom that just barely fits all of us. There’s a little room to spill out in an adjacent lab space; I expect to do so for some group activities that will require more space. The class has 17 women (85%), which tells you something of the trends we are seeing. (For reference, the baseline average is 60% female across the college, but my classes are typically two-thirds to three-quarters women.) The students seem eager to learn and I’ve had no trouble getting students to participate in class discussions and group work.

On the first day I gave a 15-minute quiz based on Energy concepts they should have known from last semester. (I had warned the students a week ahead via e-mail.) After the quiz I had the students work in groups to come up with a working definition of energy, list types of energies, and then generate a mind-map to relate their different ideas about energy. (Class went really well in my opinion.) After class I read through the responses, chose one question (a definition of the Ionization Energy of an atom) and picked out six student responses. The next class, we started with the students critiquing the anonymous responses to illustrate how one writes out a clear answer without vague or extraneously incorrect information. After discussing this as a class, I gave them back their ungraded quizzes and for homework, they would make any corrections they chose and resubmit the work the next class. (I’ve now graded it, and it was much improved.) Hopefully that set up the quality of work I will receive from the students as the semester progresses. We’re now knee-deep in the First Law of the Thermodynamics and how to calculate and make use of Enthalpies.

In my nonmajors class, we started by discussing “What is matter and why does it matter?” It is a story that starts with the students declaring that matter is made up of atoms, my challenging this assumption, and then a whirlwind tour through Greek philosophy, alchemy and attempts to synthesis the philosopher’s stone. (I’ve done this sequence many times!) Then we discussed the scientific method, and the importance of measurements in science, ending up with Archimedes’ eureka moment, different density of metals, the density of water and human beings, and body-mass index. Class #2 began with a slide on the making of Polyjuice Potion and alchemical thinking, and I’ve connected this to a quiz to calculate density of a liquid, and a “formative-assessment” question about what happens when two liquids are mixed. It required the students to take a scientific approach and reason possibly about what is happening with the molecules they cannot see. (The class material then continued into molecules, compounds, mixtures, and phases of matter. There were too many definitions so some parts of the class were rather tedious; I need to restructure this section a bit differently.)

Fun things I did include embedding a secret word (“snake”) in my syllabus to check if students read the syllabus before the first day of class. The majority did so, but some didn’t. The best guess from someone who hadn’t read it was “waffle crisps”! For my formative-assessment question and quiz, I have pictures of green liquids to match the Polyjuice Potion theme. For some reason, when you search the web and get hits on “making polyjuice potion for your party”, they all seem to be green liquids. Slytherin? Snake shedding its skin? I don’t know because I chose not to go down that web-surfing rabbit-hole.

Overall, my first week classes went quite well (in my, perhaps limited, opinion); a similar thing happened last semester. This counterbalances the research-related hardware problems I’ve been having. Besides the lab server going down, we’re fighting problems with the new blade cluster showing some odd behavior resulting in load spikes on some nodes – which then slow down all the other jobs possibly related to I/O. Perhaps it’s a good thing that Hogwarts and the magical world is forced to avoid electricity and computers. Sometimes the latter are a real headache. But for many of us Muggles, computers are the magical black boxes that keep things chugging along. Until they don’t.