Quiet Avogadro

Atoms and molecules form the bedrock of chemistry. But in the early days, there was much confusion. Dalton, of Atomic Theory fame, sometimes used the words interchangeably and as a result he thought the formula of water was HO, and that one atom of hydrogen combined with one atom of oxygen to form one atom of water. In 1811, not long after Dalton’s famous treatise on atoms was published, a quiet Italian professor from Turin, Amedeo Avogadro, published his famous treatise on molecules. No famous scientist commented on it. Hardly anyone knew it existed. The quiet Avogadro wasn’t famous nor did he try to be.

 

At the famous 1860 Karlsruhe meeting that brought together the most eminent chemists in the world to solve the confusion wrought by atomic theory and differing weights and measures, Avogadro had already passed away. We might not have known about him, if not for the young firebrand Stanislao Cannizarro who passionately argued that Avogadro’s hypothesis solved all the arguments in a single stroke. The reception was lukewarm, but several esteemed chemists later read Cannizzaro’s pamphlets that were distributed at the conference, and the revolutionary conversion began. Slowly yet surely, Avogadro’s ideas began to percolate through the chemical community.

 

I’ve been reading about the history of chemistry and its early modern founders in Bernard Jaffe’s Crucibles: The Story of Chemistry (From Ancient Alchemy to Nuclear Fusion, 4^th revised edition). The chapter on Avogadro is preceded by one on Dalton and another on Berzelius, famous for their contributions to atomic theory and its systematization respectively. In my first day of an introductory chemistry class, I clearly define the terms atom, molecule, compound (and somewhat vaguely define the term element). I spend most of my time on Dalton’s Theory and use the systematic terminology and symbols of Berzelius. Avogadro gets no mention until a few classes later when we discuss the mole.

 

Reading Jaffe’s book reminded me that I have not been giving Avogadro his due. Once again he gets overlooked. His famous hypothesis is present in chemistry textbooks: “Equal volumes of all gases under the same conditions of temperature and pressure contain the same number of molecules.” It doesn’t fit well in that first textbook chapter because for the students to understand the full impact would require us to delve into the properties of gases in detail (which we do later in the semester). Ironically, today’s popular G-Chem textbooks sequence the chapters according to the Molecular approach. And I use Avogadro’s clean definition of a molecule on the first day of class. It’s elegant and obvious to the students. We do not know what it was like to experience the confusion of the nineteenth century chemists. I once considered rearranging the material so that Gases would be the running theme throughout the semester, but that never panned out. (I once designed and ran an activity based on Avogadro’s hypothesis for non-science majors classes; I think I only ran it twice.)

 

Avogadro’s name lives on in his eponymous number, which was only established a century after his famous paper. Jean Perrin painstakingly counted tiny particles for weeks on end through a microscope. Not long after, Irving Langmuir proved that the hydrogen molecule contained two hydrogen atoms. Seems so obvious today, but not back then. Avogadro had, in fact, distinguished an integral molecule (of any compound) from a constituent molecule (only containing a single element) which is how we cleanly define a chemical compound as being composed of two or more elements. Jaffe writes that Gay-Lussac, whose observations led to Avogadro’s hypothesis, had “expressed the hope that ‘we are perhaps not far removed from the time when we shall be able to submit the bulk of chemical phenomena to calculation.’ Avogadro’s contribution to chemistry showed the way. It led also to a final agreement as to the true formula for water.” We take it for granted that balancing chemical equations and stoichiometric calculations are fundamental to the science of chemistry, but this was hard-won territory. And it’s thanks to the quiet professor, Amedeo Avogadro, but also his louder champions.

Attention Matters!

You’re reading something, then all of a sudden, BOOM! Out of nowhere a stray thought flies in and disturbs my concentration. I’ve noticed this happens more as I’ve aged. I’ve heard anecdotally that peak concentration is age 20. That’s the age of many of my students, and they have trouble concentrating. I used to worry that I could no longer focus. But now I think that having stray thoughts is natural. Often the first stray thought is related to what I’m reading (and sometimes relevant and useful), but if left unchecked it daisy chains into other stray thoughts further afield. At some point, I’m distracted and have lost all attention on my original task.

 

Today’s post is about Chapters 4 of Michelle Miller’s book Remembering and Forgetting in an Age of Technology. It builds on my previous post on how memory works from Chapters 2 and 3. Attention is the key thing I’m trying to marshal in my students when we’re in class together. Marshal is an appropriate analogy; I’m trying to direct students’ attention so they focus on the right things needed to learn the material. The more students can pay attention and be less distracted, the more they are likely to learn, especially if that attention is reflective rather than being like mindless sheep. Thus, I’m a marshal and not a sheepherder. (My apologies to sheep; I’m just using them as a metaphor here.)

 

What are we trying to do? Help students learn new things. To do this they have to make memories – in particular, semantic memories (see previous post for definition). But there’s a battle for attention. Our ancient brains have evolved to constantly be aware of peripheral changes. You don’t want to be food for the predator hiding in the bushes. Thus, you naturally perk up at distractions. No lions and tigers on my campus, but cellphones abound. Miller writes: “Distraction is kryptonite for memory, and unfortunately, distraction is what personal technology does best. Left unchecked, the alerts generated by the myriad programs that most of us use in the course of a day will inevitably erode memory. This is not because the constant interruptions permanently alter us at a fundamental level, but because they interfere with the process of making new memories when they’re happening. This is a significant threat.”

 

Let’s get to the nuts and bolts. How does attention work? Turns out if you’re trying to pay attention your brain must do two things simultaneously: shine a spotlight (by directing cognitive resources) at what you’re attending to, while suppressing what is irrelevant. This means your brain will “constantly scan the environment for stimuli what might be important”. Your brain is always multi-tasking. It’s a tricky balance “between letting too much in and keeping too much out”. Miller prefers the metaphor of a bouncer to a spotlight or a gate. The bouncer needs to actively scan for the desired guests (to let in) while keeping the riffraff out and watching for signs of trouble.

 

Most of the learning we do in school (being biologically secondary) is effortful. My chemistry students aren’t going to be learning by osmosis. (A chemistry metaphor!) So if their attention is elsewhere during class, they aren’t going to be learning in class which is where some of their best learning can happen – when you’re there as a partner to converse in the language of chemistry. Is it true that students can only be attentive for 10-15 minutes at a time? Turns out this isn’t true. Miller debunks this myth along with another that claims there is an attention time-span – there is a “capacity” or “bandwidth” of attention, but it’s not related to time. That doesn’t mean you shouldn’t switch back and forth between activities. Well-designed switches and pivots can help to focus attention. And sleep-induced death by droning through Power Point slides is real.

 

Miller also debunks the idea that “technology is to blame for shrinking attentional capacity” or that it “burns us out mentally and neurologically”. Distractions can be a problem (see quote in the third paragraph) but not because technology use is eroding your brain. I’m not going into the details Miller provides, but I highly recommend Chapter 4 of her book if you’re interested in the evidence she provides. I will however provide one salient quote: “Our ability to stay attentive even when we’re bored or disengaged may not have decreased, but perhaps our willingness has… we may have experienced a global decrease in our tolerance for the discomfort of empty time or activities that aren’t enticing.” Here’s another teaser for her book: Miller also discusses the connection between burnout and “continuous partial attention”, an activity many of us professors engage in when we have our e-mail, Slack, social media, and phone notifications turned on.

 

Our brains multitask all the time. The integration of different subsystems working in parallel is remarkably seamless; we hardly notice it… until we do. When there are multiple tasks that require significant cognitive resources and conscious attention, that’s when we run into problems. You may have heard about the costs of “task switching” and that’s what the studies show thus far. I’m going to do it right now by mentioning what seems like a tangent. Miller has an interesting discussion on the doorway effect. It’s what happens when you walk from one room into another, get distracted, and don’t remember why you entered the room in the first place. As you walk out past the doorway, you suddenly remember again. It has to do with prospective memory (which is different from episodic, semantic, and procedural memory).

 

Now back to our main discussion. Miller and colleagues have worked on a project titled Attention Matters! – the title of today’s blog post. It’s a module with three short units. The students watch some short interesting videos about the limits of attention (“The Amazing Color Changing Card Trick” and “The Impossible Texting and Driving Test” are mentioned – I watched both). These videos prompt a discussion about attention and memory and how to get the most out of their learning. But the key at the end is getting students to make behavioral changes. Miller has used the hypocrisy effect to great effect! The idea is “persuading people to change behavior by asking them to take a hypothetical stance on an issue or to articulate a desired point of view. Once they give a hypothetical opinion on a subject, people tend to stick to that opinion, despite the fact that it was only something they said because they were asked to do so.” Basically, Miller asked students to “write down their plan for how they would manage distractions going forward” in concrete terms. I really liked this idea and I think I will try it with my first-year academic advisees in the Fall semester.

 

My original plan for this post was to also discuss Chapter 5, but you, dear reader, might be reaching your attention capacity so I’m going to stop momentarily. My quick synopsis: Miller provides a nuanced discussion of whether, when and how technology (laptops, tablets, phones) should be used in the classroom. It can both help and distract. There are some very interesting experiments (go read her book!) and she does a particularly nice job summarizing the studies that have looked at the effects of note-taking old-school (pencil and paper), using a stylus on a tablet, and typing on a laptop. I won’t tell you the conclusion to keep your interest piqued. There was also an interesting aside about the effect of taking pictures when you’re on vacation and how that affects your memory of what you photographed.

 

In looking back at my previous posts, I realized I’ve discussed attention multiple times in my blog from other books I have read, but because my blog is written to offload my thoughts and memories, I couldn’t recall chunks of what I had written. But I knew where to find it! Miller also discusses this phenomenon. But here’s a selected list of my previous posts by title, more for my own use.

·      Paying Attention to Attention

·      Attention Arms Race: Ad Version

·      Filtering Attention

·      The Distracted Mind

How Memory Works

Worried that Google has rotted your memory and that of your students? Then, this book is for you: Remembering and Forgetting in the Age of Technology: Teaching, Learning and the Science of Memory in a Wired World. The author is Michelle Miller, a cognitive psychologist from Northern Arizona University. Her previous book, Minds Online: Teaching Effectively with Technology, is superb and I blogged about it eight years ago. It’s a book I regularly recommend to others interested in the topic, and I’m pleased to say that her latest book joins the list of books I would recommend to my colleagues. Today’s blog will touch on Chapters 2 and 3.

 

Miller discusses some neuromyths, and provides some historical background to the evolving models cognitive scientists have used to uncover how human memory works. Memory is not like taking a videorecording. This misconception misleads us teachers to “assume that just because some new piece of information was introduced during class, students would naturally notice and remember it.” There’s also the classic three-box model of memory that uses the metaphor of a factory conveyor belt to move information from short-term to long-term memory via the technique of rehearsal. (I recommend reading Chapter 2 in Miller’s book for why this model doesn’t work so well.) Neither are students’ brains like containers to be filled with knowledge through transmission into a computer-esque memory bank.

 

Our brains aren’t a blank slate to etch or “code” memories into. Instead, when we learn, we re-code. In fact, every time we try to rehearse a piece of information, we are recoding. But rehearsal isn’t necessarily the best way to recode or to really learn the material. We’ll get to more effective methods a little later, but first I want to highlight the groundwork Miller is laying down. She outlines the evidence for the different subsystems of working memory. One of these is a “visuospatial sketchpad… [which] kicks in when we are doing mental tasks where visualization is key” – this is very relevant in chemistry problem-solving. Several subystems relate to language analysis, and it’s amazing how we parse language and meaning in our native language so fluidly! Miller also goes into detail on the phonological subsystem, it’s the best-studied one. Where it’s important in a subject such as chemistry with significant new scientific terminology: it’s “job is to replay and refresh the pieces of the word’s sound, buying time while other mechanisms create a permanent representation of that new word.”

 

What about long-term memory? It’s that significant limitless “bank” which someone with expertise draws from, myriad connections and all. Miller distinguishes the three types: episodic, semantic and procedural. Episodic memory is tied to a specific experience that you have and you can remember the place and how you were feeling. It’s why certain memorable experiences even from long ago can be triggered. In chemistry class, students will remember a flash-bang demo with surprising sounds, colors, and smells, that they may not have expected! Semantic memory, the primary target in my chemistry courses, is the buildup of conceptual knowledge organized in some form or schema. The richness of semantic memory is what distinguishes the expert chemist from the novice. Both episodic and semantic memory can be triggered by the appropriate cues. Procedural memory is what allows you to carry out a practiced skill without taxing your working memory; knitting or driving a car are examples. In chemistry lab, you can clearly tell the students who’ve had more practice pipetting than others.

 

We remember and we forget. Why does memory work the way it does? Miller’s answer in a word: Survival. “Instead of being a place to store things, memory is an ability that our minds and brains have evolved in order to keep us alive… communication, avoiding danger, prospecting for good thing out there in the world, replicating strategies that have served us in the past, distinguishing friend from foe, solving problems and acquiring skills… makes it more likely that we’ll have only the most relevant, most useful material on hand, and that we will be able to really pick out the thing we need when the chips are down. It also explains the exasperating, now-you-see-it, now-you-don’t quirks of long-term memory.”

 

Miller does a particularly good job articulating why committing certain things to memory is important in learning. She effectively argues against tropes such as “drill and kill” and she highlights problems with the hierarchical representation of Bloom’s Taxonomy. I wholeheartedly agree with her point that memory is an important pillar of learning, and she provides evidence of how strengthening or enhancing memory is crucial for complex reasoning, that “memory and thinking skills enjoy a complementary, not competitive relationship within learning.” I like how Miller cuts to the chase: A key problem in learning is “transfer”, the ability to apply conceptual principles to other cases beyond the exact examples you’ve seen before. Effective memorization of information helps you with transfer. In Miller’s words, transfer “is what makes learning useful.” But it can be hard to do with information that’s not a matter of life-and-death; don’t forget that our brain evolved for survival!

 

Fortunately, we now know more about how humans learn (and we’re still learning) and we can design activities to enhance useful or effective learning. Miller provides examples of how memory tasks can help students develop metacognition in their learning. She provides practical examples of why you might need (as a practitioner) knowledge at your fingertips. As a teacher, if I kept having to look up every piece of information, I’d be a goner. Instead, I try to model in class which pieces of information I need to have immediately available, and which ones students shouldn’t need to memorize. (I actually look them up in class.) But committing information to semantic memory isn’t easy especially since much of what we do in school is biologically secondary. But it’s not easy. Miller reminded me that “it typically takes students a lot of practice and a lot of insight to achieve transfer, and is an area where teachers typically overestimate how quickly and well students really are achieving it” (emphasis mine)!

 

Given the importance of building and enhancing memory, how can we best go about it with our students? Here are my quick summaries of the principles Miller provides:

 

·      Meaning and structure. The key here is meaningful interpretation, and helping students build an organizational scheme. We do this via scaffolding. We do this by telling stories, i.e., providing a narrative structure.

·      Visualization. Humans have evolved to prioritize vision. It’s why a good figure is indeed worth a thousand words or more. That’s why I favor textbooks that not just have good narrative structure, but have excellent figures that are well-designed for learning and not just a pretty picture.

·      Emotional charge. There’s no doubt that emotions heighten memory. For the classroom, there’s evidence that providing a supportive and nonthreatening environment promotes learning. The emotion of surprise can be very effective (we remember plot twists in a story). I’ve been trying to build in more of these aha moments into class.

·      Attention. Duh. Maintaining attention is surprisingly tricky. Much of classroom organization is about this.

·      Connection to goals. I thought this would be more important, but Miller downplays it. Without the other factors, being motivated (having a goal) isn’t quite enough but it can help with attention.

 

Miller goes through several pedagogical strategies to achieve the task of enhancing memory. I was familiar with all of these and they fall under the large rubric of “active learning” approaches. Which strategy you use will depend on who you are, your subject matter of the day, your goals, and who your students are. Local context matters. This is why I’m skeptical of those who promote their particular (and often narrow) pedagogical approach as a silver bullet. I don’t promote my own particular approach either. It works for me. I’m willing to share what I do with others if they’re interested, but I’m not interested in pushing pedagogical strategies.

 

That being said, Miller is preaching to the choir when she highlights one technique that works very well for students: retrieval practice. She writes: “Rarely have we seen a set of findings with such clear and compelling implications for learning… Essentially, what the studies demonstrate is that when students answer questions about material, they remember it better and for longer… It works best when students get immediate feedback, and when the questions are open-ended or short answer in style.” It’s why I give many low-stakes short quizzes at the beginning of class. It’s why I give closed-book exams and require students to generate, and not just recognize, answers. It’s why I try to phrase my study guide in the form of questions and give students questions to test themselves. It’s why I’m always asking them to explain, explain, explain. Some students find it frustrating that I always ask “why” in response to an answer they’ve provided after an initial question. In my experience, this is an effective technique (although not the only one) to learning an abstract, conceptually challenging, jargon-laden, subject such as chemistry. We need to help our students move away from sub-optimal techniques (which Miller also discusses).

 

Miller provides effective rebuttals to those who “are heavily invested in the philosophical stance that tests are a creativity-killing blight on education” and who think that testing only leads to superficial learning. She also addresses the notion that “testing kills authentic enthusiasm for learning and heightens anxiety” – the claim is not only highly subjective, it can “become a self-fulfilling prophecy”. Approaches to testing can be done well and they can be done badly. Low-stakes quizzes help smooth the path, or you could even pipe in a fun way of doing this via Kahoot and other applications that Miller describes. And technology can help our students with retrieval practice. We shouldn’t shun it where it can be very useful.

 

Towards the end of Chapter 3, Miller discusses the symbiosis we have with our electronic information-providing and information-storing devices. Part of why I blog is to offload things I learn from books I’ve read so that I know where to find that information (with “search”!) but I’ve also noticed that by doing so, I do not retain as much of this information for immediate use (the so-called “Google effect”). And that’s okay. But if I didn’t write about it, I’d probably remember less. But I do agree with Miller that “when it comes to the bedrock knowledge of a discipline or professional skill, students shouldn’t fall to looking things up.” This of course begs the question of what that bedrock knowledge is in one’s discipline. Ah, a subject for a different post!

 

P.S. This is the fifth book I’m reading in the “Teaching and Learning in Higher Education” series. For links to the other four, see this previous post.

Conversing in Chemistry

I’m teaching myself Spanish. Very poorly, I might add, if my goal is to be a facile speaker and listener. These days I rush through Duolingo, trying to keep my daily appointment with Duo to under 15 minutes. My motivation is low. It was higher six months ago when I was also listening to several Duolingo podcasts and then going through the transcripts. But I got lazy. I’ve also avoided being in a position where fluency in speaking and listening in Spanish matters. I don’t have the skills. My learning efforts are minimal. And what I am good at is recognizing the tricks to speed my way through Duolingo. My reading of Spanish has improved, and my vocabulary is a little wider, but that’s about it.

 

I will know that I have learned Spanish adequately when I can hold my own in an everyday conversation (both speaking and listening) with another adult without long pauses or being extra slow. It’s a competency that is easy for me to self-assess. My interlocutor will also know whether or not I have the basic competency from a short 15-minute conversation. My goal in Spanish is skill-based. Have I mastered the skill to the desired level or not? It is quite easily demonstrable. Right now, my skill level likely matches a seven-year old, with the vocabulary of an eleven-year old.

 

What is the skill of Chemistry? Is it analogous to Spanish? How do I know if I have mastered the skill to an adequate level? As a teacher, how do I know if my students have done so? Let’s take first-year college General Chemistry as an example. There is a list of learning goals and student learning outcomes, along with (partially vague) statements beginning with: “By the end of this course, you will be able to…” And how will we know if a student has met the objectives? There’s an assessment. Most commonly it’s a final written exam – which, in my opinion, is a good way to assess the knowledge the student has acquired, both conceptual and procedural.

 

The word ‘skill’ is more easily linked to procedural knowledge. In an assessment, we can test it by giving students a problem to solve. If the student can solve the problem, procedural knowledge has been demonstrated. In a well-designed problem, conceptual knowledge can also be indirectly assessed. But I have come across many instances where a student can solve a numerical problem with just a vague notion of key conceptual pillars. That’s why my exam problems regularly ask students to explain, explain, explain. It’s why in class or in my office, when a student answers a question, I always follow up with “Why?” regardless of whether the original answer is right or wrong.

 

I believe that asking students to generate an explanation is crucial. That’s why I hardly use multiple or fill-in-the-blank questions – asking the student to recognize a conceptually sound answer compared to an erroneous one isn’t enough. It is possible to design very good two-stage multiple-choice questions with very plausible sounding conceptual answers, but this takes a lot of work. And I’m lazy. Or I should say, the cost-benefit ratio isn’t favorable at the moment. I’ve tried asking ChatGPT to generate high-quality assessments in this vein, but so far it hasn’t performed to expectations. (It can generate decent open-ended questions with appropriate prompts.)

 

The move to online homework systems in college-level General Chemistry is practically complete. It’s very difficult to go back and ask instructors to generate and grade homework and problem sets. We have large classes. We have time constraints. We have a host of other commitments. We’re lazy. We recognize the limitations of these systems, and the tech-companies are trying to oblige by convincing us that they are overcoming these limitations. “Adaptive learning” systems, previously a curiosity, is now embedded by all major players. “We’ll take care of it for you,” they say. “We’ll give them the skills and by demonstrating those skills, we know they’ve achieved the learning goals YOU, the instructor, have set.”

 

How does one assess such skills? By atomizing them. (Doesn’t this sound soooo appropriate in chemistry?) There is some value to this approach. If students achieve fluency on an atomized task, they can “chunk” it into long-term memory, thus freeing up cognitive resources for more complex and deeper learning. If that’s how you’re using the online homework system, it’s appropriate. But don’t make the mistake of thinking that by “mastering” these atomized skills, the students have learned how to be conversant in the language of chemistry. Quality feedback is crucial.

 

But what does it mean to be conversant in chemistry? You have to know the vocabulary. You have to use that vocabulary in the appropriate situation both effectively and intelligibly. Experimenting with ChatGPT has reminded me that a data dump with plausible sounding language isn’t being conversant in chemistry. But it’s hard to nail down exactly what the gestalt experience of understanding chemistry is. That’s because the referents of chemistry are unseen tiny entities, and much of chemistry reasoning is in the realm of abstraction, translated by analogies and metaphors. It’s what makes chemistry particularly challenging to learn: Conversation about the concrete (what you can see and taste) takes place in a seemingly alien world of abstraction such as the fuzziness of orbitals and the fluidity of energy.

 

Conversation is how we assess fluency. Ideally, I could set up hour-long oral final assessments with each of my students and have a conversation with them by asking them questions. That’s not practical unless I have a very small class. But a written final exam is a reasonable substitute. I have a series of questions that requires the students to be conversant in chemistry by writing down their explanations and supporting their answers with graphs, equations, calculations, analogies, and metaphors. (I have not dared to try a Reverse Final yet.) To prepare them for my final exam, they have to see this being modeled (by me talking and writing things on the board in class) and practice (in homework, quizzes, midterms), and by conversing with me and with each other in the shared language of chemistry.

Geeky Pedagogy

Geeky Pedagogy, written by Jessamyn Neuhaus, is aimed at teachers who are also geeks, introverts, nerds. Her book spoke to me. I’m definitely an introvert, but I hadn’t thought of myself as a geek or a nerd. I wasn’t considered an oddball in school – at least I don’t think so – nor was I labeled or treated as being from a strange tribe. (I also went to school in a different country with a different education system so perhaps the same tropes don’t apply.) But reading Neuhaus convinced me to embrace my inner geek or nerd when it comes to my subject of expertise: chemistry!

 

Even if you’re not a geek, introvert, nerd; if you care about student learning and continuing to improve as an effective teacher, I highly recommend you read Geeky Pedagogy. While there are helpful tips and tricks, thoughtful analysis about teaching, great suggestions and recommendations, for me the best part of this book was being inspired to continue in my journey of being an effective teacher. Not a super-duper teacher or the perfect master-teacher; no such individual exists. Rather, one that continues to be self-aware, reflective, and puts into practice all the things I’m constantly learning about learning!

 

Having immersed myself in the Scholarship of Teaching and Learning (SoTL) for over a decade, I was familiar with the many SoTL “suggestions” that Neuhaus includes in her book. But she is strident about one point, which I agree with wholeheartedly: “Whatever the SoTL recommends, whatever your mentor tells you, even whatever worked for you in some other teaching context, may or may not work for you in your current localized teaching context. There’s no one specific hard and fast method for building our pedagogical practices, no one specific way it must look or one specific thing we must do in all teaching scenarios for all time. This applies to everything from the most sweeping pedagogical theory to any single teaching trick. It applies at every stage of our careers, from our first class to our last… ultimately [you] have to do whatever it is that works for you and advances learning among your students.”

 

Geeky Pedagogy reminded me of the importance of awareness and self-reflection. Sometimes, when I feel busy and pressed for time, I don’t the time to reflect after class or I’m not sufficiently self-aware during class. It’s easy to get distracted. Just two days ago, I had to wrangle with the technology in the classroom and it took me ten minutes to get the projection system up and running (when it normally takes a minute or less). Thankfully I got to class ten minutes early for my 8am Monday morning class. But because of all that, I missed chatting with my students before class, and I felt flustered. It took me a little time to regain my self-awareness and be really present for my students, and not just think about what I was going to say next. It was good to be reminded by Neuhaus about the importance of giving one’s full attention to the students and their learning during class – and not just what I had planned.

 

Planning, though, is also very important – particularly if you’re an introvert and/or find it challenging speaking extemporaneously. I plan a lot. These days, my students don’t realize how scripted my plan is – I have chunks of it memorized which also include when I will throw in a joke or a reference to pop culture. The only reason it seems seamless to the students is because I’ve had lots of Practice. Neuhaus underscores the importance of Planning and Practice; I discovered this on my own as a novice teacher. Practice, practice, practice. I tell my students the same thing. But the practice must be reflective to be effective. Students can repeat the same exercises over and over with little learning if they don’t do so reflectively. The same is true of the practice of teaching. I imagine I could go on auto-pilot having taught the same material many, many times. But then I wouldn’t improve. Actually, I would get worse because I’d be unaware of local context. Our students change. Each class is a new and different group. And it’s crucial I connect to them as individuals, and not just as a nameless crowd.

 

Of the many things I’ve read about the dreaded topic of the end-of-term student evaluations of teaching, Neuhaus provides the most balanced perspective I’ve come across. For that alone, her book is worth reading (or at least Chapter 3: Reflection) but there’s so much more that you might find inspiring and helpful if you’re a teacher who wants to get better at helping students learn. For the geek/introvert/nerd in me, Neuhaus explained (better than I could) why certain things I’d been doing worked well. It was a Know Thyself moment for me. Her book also gave me fresh encouragement to be and do better, not in an unattainable preachy way, but by reminding me that teaching is effortful and that it is a lifelong journey of learning how to help students become better learners. And it helped me embrace my geeky love of all things chemistry! Whenever I feel low about teaching, Geeky Pedagogy is the book I will be re-reading.

 

P.S. I’ve been working my way through the “Teaching and Learning in Higher Education” series. All short books, the ones I’ve previously blogged about are The Spark of Learning 1 2 (Cavanagh), Ungrading (Blum), and How Humans Learn (Eyler). Geeky Pedagogy is the best one so far.

Analogies and Acronyms

Explaining something successfully is greatly helped by using an appropriate analogy. That’s because it’s much easier to learn something new by scaffolding it to previous knowledge. Without any scaffold, if you’re trying to learn a bunch of new things simultaneously, your working memory gets overwhelmed. Prior knowledge of the vocabulary is crucial. If you don’t understand the words, you’ll get bogged down very quickly. For example, an introduction to Atomic Theory could have been written as “Uncleftish Beholding”. As a chemist, I can see what’s going on but it’s still a struggle. For a non-chemist, it reads like utter gobbledygook.

 

I first learned science in high school in a language that was not English. Scientific language did not use everyday terms and I was totally lost. I couldn’t even understand the definitions. Things seem a little easier in English because words such as “atomic” and “theory” have everyday meanings. But there are problems. In a scientific context, a word might have a very precise meaning. While in everyday use, its meaning might differ. For example, the scientific definition of theory (which means very well supported by numerous facts) carries connotations almost opposite to how the word theory (which might infer something that has little basis in reality).

 

We can’t see atoms or molecules. But we can picture them with analogies such as balls connected by springs. The balls have different sizes (as atoms do) and different colors to represent the element (which isn’t true, but the colors are extremely helpful for visualization). We represent these atoms by symbols: H, O, Na, Cl. With these symbols we construct chemical “formulae” such as H₂O, HCl, NaOH, and NaCl. For the trained chemist, each of these formulae trigger a wealth of associations.

 

For example, by seeing the formula NaCl, I simultaneously picture table salt (white and granular). But in my mind’s eye I also see a crystal lattice consisting of a face-centered-cube of larger chloride ions with sodium ions in the octahedral holes. My mind then jumps to the lattice energy, that can be calculated by a Madelung “sum” of Coulombic terms that represent the ionic bonds. (I’ve inadvertently introduced jargon that the non-chemist will find obtuse!) This then makes me think of the enthalpy of dissolution of NaCl in water, which is an endothermic reaction with a very small delta-H. Thus the dissolving of table salt in water is entropically-driven at room temperature. NaCl probably has a K_sp > 1. I picture ions being pulled out of the lattice by polar water molecules and I recognize that this is an electrolyte. The solution has pH 7 because HCl and NaOH are strong acids and bases that react to form NaCl. And I could go on. The point here is that seeing the symbols NaCl immediately generates a wealth of connection in my minds.

 

A beginning student in chemistry won’t be making those rich connections. The student might still be thinking: What is Na and where is it on the periodic table? In my mind, there are analogies galore. I’m picturing not just colored balls in some arrangement, but I see mathematical equations, fields of force, energy diagrams, and more. And in class, when I discuss the structure, formation and dissolution of NaCl, I have analogies to bridge the gap to help students gain the type of expert understanding that I have. I want them to be able to evoke the rich set of connections that helps them understand what chemistry is all about (really)! As they make more connections and “solidify” their understanding (ah, another apt analogy!), building on this scaffold (another analogy!) helps them learn more and learn deeper. Analogies are everywhere. You can’t think without them. You can’t talk without them.

 

I’m teaching myself biochemistry. I’m not an expert. Yet. One of the things I’ve been wading through is the alphabet soup of acronyms. An acronym is a stand-in, that once you understand it, allows you to reduce your cognitive load by using it as a scaffold to learn more complex things. One acronym we’re familiar with is DNA. An acronym “hides” details, and by doing so, allows you to use it as a conceptual piece to build up a web of information. (Why a web? Why not a jungle?) As a chemist, I’m still hung up on the detailed chemical structure, but when one gets to regulation and control, you want to think of these macromolecules as blobs with acronym names: ATP, AcCoA, NADH. I’ve even started using three-letter acronyms for the molecules in the Krebs cycle: ACE, OXA, CIT, CAC, ISC, AKG, SUC, MAL, FUM.

 

I’ve come to appreciate that acronyms are not just shorthand so I don’t have to say a mouthful for a name, but once I know what they mean (chemically), they release my mental resources to build on the scaffold. This is one of the humps that students need to get over. It’s why they should memorize the three-letter and one-letter codes for amino acids, and have a good idea of what the side chain looks like and its properties. Without internalizing this, every time they look at an enzyme active site or read about single-site mutation studies, they don’t really “get” what’s going on because they’re still stuck in trying to determine what Ser-His-Glu is before they can understand its role as a catalytic triad in AChE (acetylcholinesterase).

 

Analogies and Acronyms: We need them to learn new and complex things! As teachers we should utilize them in powerful ways to help our students make the journey from novice to expert.

Transformer

I took lots of notes while reading Transformer, Nick Lane’s latest book. I’ve enjoyed his engaging prose since I stumbled on Oxygen many years ago. Back then, I wasn’t all that interested in biochemistry. Now, I’m fascinated by the subject. The subtitle of Transformer is “The Deep Chemistry of Life and Death”. Sounds like a tall order to explain such a topic.

 

Lane focuses on the Krebs cycle, familiar to students of biochemistry or introductory biology. But he spends quite a bit of time discussing how and when the cycle might run in reverse. This aligns very closely to my own thinking and research in the chemistry of the origin of life, so Lane is preaching to the converted in my case. Many of the chemical details were familiar to me, but I still enjoyed his presentation couched in history and a discussion of the scientists involved.

 

Things that jumped out at me:

·      The role of Rubisco: I did not know about its role as a “safety valve” in photorespiration to resupply NADP⁺ for ferredoxin. I’d always wondered why nature would keep such an inefficient enzyme, but Lane’s explanation made sense.

·      While the reverse Krebs cycle is autocatalytic (which is important if it plays a role in the chemical origins of life), the forward Krebs cycle is not; in the oxidative direction it is catalytic, but not autocatalytic. I hadn’t previously considered this difference.

·      Lane puts Orgel’s criticisms about “Metabolism First” in context and threads the needle to compromise between ideal autocatalysis and too many parasites bleeding off intermediates from the cycle.

·      The conditions under which dehydration might be favorable in a “watery” environment.

·      The pH challenge: CO₂ activity is favored by acidic conditions, while H₂ activity is favored by alkaline conditions. Membranes come to the rescue to take advantage of a pH gradient.

·      Biochemical metabolic efficiency for aerobes versus anaerobes connects to the rule-of-thumb of 5 versus 2 trophic levels.

·      Planet Earth is like a “giant battery”, negative (reduced minerals) inside, positive (oxidized atmosphere) on the surface. Volcanoes and hydrothermal vents connect the two! Cells might be analogous with membrane proton pumps as the connection.

·      It’s difficult to use the proton gradient to both reduce ferredoxin and generate ATP simultaneously.

·      The Krebs cycle has two prongs with succinate as the tipping point. Gotta balance growth, reproduction, and staying alive!

·      Mitochondria are flux capacitors.

 

A later chapter on cancer was tougher-going for me because I was not as familiar with the biology and biochemistry. I was reminded how challenging it can be to learn something new where I lacked the specialized vocabulary. But I’m motivated to learn more about control systems in biochemistry so I expect to re-read parts of Lane’s book with a biochemistry textbook open and with some help from the World Wide Web. What I most appreciated about reading Lane’s book was that it made me stop and think about my research projects from a bird’s-eye view, and it gave me some new ideas to explore. It’s good timing because I’m getting excited once again about my research as my semester is coming to a close and my teaching responsibilities ebb.