Blogging has been kind of slow due to the birth of my son 2 weeks ago. I’ll be back at it soon, I promise. In the meanwhile, let me briefly pause to wish a happy anniversary to On the Origin of Species, which was published 150 years ago today. I recommend that you celebrate by buying yourself a t-shirt.
A student blogger who goes by Carolyn Blogs has an interesting entry on PowerPoint lectures from the perspective of someone taking the class:
Recently I came to the conclusion that I do not learn well from classes in which the lectures are based on PowerPoint presentations… Professors who use PowerPoint tend to present topics very quickly when they don’t have to do anything but talk. If every example and every diagram is on the screen, there isn’t much time for me to take notes on the subject of each slide. Lectures aided by chalkboard visuals are easier to take notes from because I can write what the professor writes on the board at the same time. Also, because there is usually more chalkboard space than screen space, if I am behind on note-taking, the visual will probably still be on the board for me to copy a few minutes later. A lot of professors try to solve this problem by handing out the lecture slides before class, or by posting them online. While this is great for a lot of students, it doesn’t work for me because I learn best and am most engaged if I have to take notes as if my grade depended on having a great record of the class and I would never see the material again. In classes with handouts, I tend to zone out and have to work harder to pay attention. Studies have shown[pdf] that taking high-quality notes improves organic memory: I rarely use my notes after the lecture because the act of physically writing information down helps me remember more of what goes on in class.
A few years ago I started phasing out PowerPoint from my upper-division classes (I never used it for grad classes). Carolyn hits on pretty much all the major reasons.
Teaching with PowerPoint has a different pace and structure than teaching with chalk or markers. It’s not just about overall fast vs. slow (though that’s part of it), but about when you go fast and when you go slow. When I use the board, I write down the major points, terms, definitions, etc. That forces me to slow down at exactly the moment when I’m making a big point and students should be attending closely. Once the critical information is on the board, I can elaborate, discuss with the class, ask questions, etc. while it hangs up there behind me for students to refer to. And since writing slows me down, I don’t give as much emphasis to relatively minor points — giving students an additional cue as to what’s more and less important. (“Don’t ignore this completely, but it’s not as central as what I said earlier.”) You can reproduce this kind of pacing and structure with PowerPoint, but in practice it’s difficult to do during a live performance in front of a classroom. You have to write your presentation with delivery (not just content) in mind. Otherwise it’s just too easy to blow through major and minor points at a constant pace.
Another point that she makes… I still use PowerPoint in my big introductory classes (though I make my own slides from scratch, use animation to help regulate my delivery, and try to avoid the mind-numbing bullety templates). I always have a few students ask me to post the notes before class. I don’t — I post them after class, but honestly, I have sometimes wondered if I’d be better off not posting them at all. Carolyn modestly writes “while [posting notes] is great for a lot of students, it doesn’t work for me…” but I actually think this describes most students. A lot of students misread their internal cues — if it feels like they are expending a lot of effort then they think they must be struggling with the material. Actually, though, if the professor is presenting challenging material, then you shouldn’t feel relaxed — relaxation is a sign that you’re probably thinking superficially or zoning out, not that you’ve quickly mastered the material.
I also found it impressive that Carolyn reached this conclusion on her own. Because frankly, it’s fundamentally very difficult to introspect into your own learning processes. A few years back, when I started moving away from PowerPoint, I got feedback on my student evaluations from people who wanted more PowerPoint. When I talked with students who felt that way, they thought they’d be able to focus more on the material if they didn’t have to bother taking notes. I realized that reflects a fundamental misunderstanding of what note-taking does for you. I’ve been getting less of that feedback lately — maybe because I’ve gotten better at using the board, or maybe because recent students have been around PowerPoint longer and see its limitations more clearly.
When students learn writing, they often are taught that if you have to say the same kind of thing more than once, word things in a slightly different way each time. The idea is to add interest through variety.
But when I work with psychology students on their writing, I often have to work hard to break them of that habit. In scientific writing, precision and clarity are the most important. This doesn’t mean that scientific writing cannot also be elegant and interesting (the vary-the-wording strategy is often just a cheap trick anyhow). But your first priority is to make sure that your reader knows exactly what you mean.
Problems arise when journalists trained in vary-the-wording write about statistics. Small thing, but take this sentence from a Slate piece (in the oft-enlightening Explainer column) about the Fort Hood shooting:
Studies have shown that the suicide rate among male doctors is 40 percent higher than among men overall and that female doctors take their own lives at 130 percent the rate of women in general.
The same comparison is being made for men and for women: how does the suicide rate among doctors compare to the general population? But the numbers are not presented in parallel. For men, the number presented is 40, as in “40 percent higher than” men in general. For women, the number is 130, as in “130 percent the rate of” women in general.
The prepositions are the tipoff that the writer is doing different things, and a careful reader can probably figure that out. But the attempt to add variety just bogs things down. A reader will have to slow down and possibly re-read once or twice to figure out that 40% and 130% are both telling us that doctors commit suicide more often than others.
Separately: why break it out by gender? In context, the writer is trying to make a point about doctors versus everybody else. Not male doctors versus female doctors. We often reflexively categorize things by gender (I’m using “we” in a society-wide sense) when it’s unnecessary and uninformative.
Ewen Callaway in New Scientist reports:
In 2007, Abdelmalek Bayout admitted to stabbing and killing a man and received a sentenced of 9 years and 2 months. Last week, Nature reported that Pier Valerio Reinotti, an appeal court judge in Trieste, Italy, cut Bayout’s sentence by a year after finding out he has gene variants linked to aggression. Leaving aside the question of whether this link is well enough understood to justify Reinotti’s decision, should genes ever be considered a legitimate defence?
Short answer: probably not.
Long answer: This reminds me of an issue I have with the Rubin Causal Model. In Holland’s 1986 paper on the RCM, he has a section titled “What can be a cause?” He introduces the notion of potential exposability – basically the idea that something can only be a cause if you could, in principle, manipulate it. He contrasts causes with attributes – features of individuals that are part of the definition of the individual. He uses as an example the statement, “She did well on the exam because she is a woman.” Gender can be statistically associated (correlated) with an outcome, but it cannot be a cause (according to Holland and I believe Rubin as well), because the person who did well on the exam would not be the same person if “she” weren’t a woman.
From a scientific/philosophical level, I’ve never liked the way they make the cause/attribute distinction. The RCM is so elegant and logical and principled, and then they tack on this very pragmatic and mushy issue of what can and cannot be manipulated. If technology changes to where something becomes manipulable, or if someone else thinks of a manipulation that escapes the researcher’s imagination (sex reassignment surgery?), things can shift back and forth from being classed as causes versus as attributes. Philosophically speaking: Blech. Plus, it leads to places I don’t really like. What about: “Jane didn’t get the job because she is a woman.” Is Holland saying that we cannot say that an applicant’s gender affected the employer’s hiring decision?
I think we just need to be better about defining the units and the nature of the counterfactuals. If we are trying to draw inferences about Jane, as she existed on a specific date and time and location, and therefore as a principled matter of defining the question (not as a pragmatic concern) we take as an a priori fact that Jane for the purposes of this problem has to be a woman, then okay, we’ve defined our problem space in a particular way that excludes “is a man” as a potential state of Jane. But if we are trying to draw inferences in which the units are exam-takers or job applicants, and Jane is one of many potential members of that population of units, then we’re dealing with a totally different question. In that case, we could have had either a man or a woman take the exam or apply for the job. Put another way: what is the counterfactual to Jane taking the exam or Jane applying for the job? If Jane could have been John for purposes of the problem that we are trying to solve, then it makes perfectly good sense to say that “Jane did well on the exam because she is a woman” is a coherent causal inference. It goes back to a principled matter of how we have defined the problem. Not a practical question of manipulability.
So back to the criminal… Holland (and Rubin) would make the question, “Is the MAOA-L variant a cause or an attribute?” And then they’d get into questions of whether you could manipulate that gene. And right now we cannot, so it’s an attribute; but maybe someday we’ll be able to, and then it’ll be a cause.
But I’d instead approach it by asking: what are the units, and what’s the counterfactual? To a scientist, it makes perfect sense to formulate a causal-inference problem in which the universe of units consists of all possible persons. Then we compare two persons whose genomes are entirely identical except for their MAOA variant, and we ask what the potential outcomes would be if one vs. the other was put in some situation that allows you to measure aggressive behavior. So the scientist gets to ask questions about MAOA causing aggression, because the scientist is drawing inferences about how persons behave, and MAOA is a variable across those units (generic persons).
But a court is supposed to ask different kinds of causal questions. The court judges the actual individual before it. And the units are potential or actual actions of that specific person as he existed on the day of the alleged crime. The units are not members of the generic category of persons. Thus, the court should not be considering what would happen if the real Abdelmalek Bayout had been replaced by a hypothetical almost-Bayout with a minutely different genome. A scientist can go there, but a court cannot. Rather, the court’s counterfactual is a different behavior from the very same real-world Abdelmalek Bayout, i.e., a Bayout who didn’t stab anybody on that day in 2007. And if Bayout had not stabbed anybody, there’d be no murder. But since he did, he caused a murder.
Addendum: it’s a totally different question of whether we want to hold all persons to the same standards. For example, we have the insanity defense. But there, it’s not a question of causality. In fact, defendants who plead insanity have to stipulate to the causal question (e.g. in a murder trial, they have to acknowledge that the defendant’s actions caused the death of another). The question before the court basically becomes a descriptive question — is this person sane or insane? — not a causal one.
I just came across a thought-provoking interview with Cary Nelson, president of the AAUP. The video is titled Twilight of Academic Freedom. It deals with the consequences of increasing numbers of “contingent faculty” in higher education — the adjuncts, visiting professors, instructors, and various other titles for instructional staff who do not have the protections of tenure.
Right now, many universities are looking for ways to save money, and one way to do that is to hire fewer tenure-related faculty and shift the teaching burden onto adjuncts who are hired for as little as the uni can get away with paying. (It’s worth noting that this trend started well before the current recession, though I wouldn’t doubt that it’s accelerated.) Nelson is concerned about universities that are moving toward having an increasing share of teaching done by such contingent faculty.
Adjunct positions have a useful place in universities when used for the right reasons. One such reason is to expose students to perspectives that come from outside of the academy. For example, my undergraduate Abnormal Psychology class was taught by an adjunct whose main job was as a clinical psychologist at a hospital. That gave her a wealth of stories and practical experience that she could bring to the classroom.
But using adjuncts as a cost-cutting measure is a different thing. Many adjuncts will tell you that the system exploits instructors who work at low wages as a way to remain in the game while they hunt for better-paying permanent jobs. Those jobs typically don’t exist in high enough numbers to hire everybody who’s circling in the adjunct holding pattern.
Nelson offers a different line of argument, one that stems from the core reason tenure exists in the first place: academic freedom. To quote from the interview, “Academic freedom and job security are inextricably linked.” Tenure ensures that a professor can choose what to teach based on professional judgment. Direct review of those decisions is made by professional peers, protecting individual faculty from legislators, donors, regents, and others who might wield their considerable influence to drum out professors who don’t fit some outside agenda.
Nelson is not just worried about individual adjuncts being vulnerable. Even more ominous are the systemic risks of a university shifting to an adjunct-heavy portfolio. Hiring the occasional adjunct at an institution with a solid core of tenure-protected faculty is not likely to be a problem, as long as tenured faculty care enough about academic freedom that they’ll raise a stink if an adjunct is being subject to inappropriate pressure. (It’s sort of intellectual herd immunity.) But without that core, when too many of your faculty could be threatened for teaching something that someone does not like, the institution loses an important protection. Just look at the battles over secondary school textbooks in biology and history for an example of the kind of political infighting that can result. Is that where higher education could end up — with a state board telling me what to teach and what textbooks to use? I hope not, but Nelson presents good reasons to worry.
Kirstin Appelt of the Center for Research on Environmental Decisions at Columbia has put together a nifty online index of personality measures. It’s called the Decision Making Individual Differences Inventory, which abbreviates to DMIDI. The email announcement I just got helpfully points out that the name “rhymes with ‘p. diddy’.” That may be my second-favorite part.
My first favorite part is that it’s a cleanly-designed, well-put-together website that looks like it will have tons of useful information for researchers. And even though it has an emphasis on measures relevant to decision-making research, the site casts a pretty wide net, including a number of Big Five measures and measures of “cognitive ability.” The latter gets snoot-quotes because for some reason economists and JDM researchers don’t like the word “intelligence.” (For that matter, they have a pretty narrow view of the word “personality” too. The section for trait measures is simply labeled “personality,” which is somehow placed in contrast to measures of motivation, attitudes, cognitive style, and ability — all of which, of course, are part of what makes you the person that you are, i.e., your personality.)
But I digress. It’s still under construction, but it looks like it will be a great resource. The site is set up as a wiki, which raises the possibility that they’ll be able to harness the academic community’s energy in updating and expanding it. I can see why they might be cautious about going down that road (who wants to moderate an edit war between a bunch of cantankerous professors?), but even in its current form it’s really nice.
I got the following email this morning. Note the part I’ve underlined:
***
Dear Introductory Psychology Professor:
[Redacted] Press was created as a faculty venture six years ago focusing solely on interactive low cost digital text packages with free printed texts. This concept has been widely accepted by faculty and students alike. The rising price of textbooks is well known to college faculty, students, and even government agencies. Our digital textbooks offer a low cost alternative to traditional expensive textbooks.
We would like to introduce you to our Introductory Psychology low cost interactive package including:
A $40 digital interactive text with embedded videos and audio and words with internet links — a better way for today’s students
A free printed text called a student text supplement
Access to a password protected website with interactive updates and materials
A test marketing program with stipends up to $8,000 for individual professors and up to $15,000 or more for departments
An online test center for each chapter of the interactive text, plus instructor’s manual
Test bank questions to upload to any online platform such as Blackboard
Technical and consulting support — 24/7
We invite you to take a narrated tour of [Redacted] Press before you review the interactive Introductory Psychology text. It is a brief tour of [Redacted] Press and interactive texts and will enable you to better understand the benefits of our program within minutes. You start the tour by going to: [URL redacted] (you can cut and paste this URL directly into your browser).This tour will demonstrate the interactive elements of our texts and give you an opportunity to review the [Redacted] interactive Introductory Psychology text at your leisure.
After you have taken the tour, if you email me your mailing address and the number of students in your upcoming classes, we will send you the digital text and brochure on the Introductory Psychology package and tailor a test marketing stipend program for you and even for your department.
We are confident you will see the numerous advantages of moving towards digital, interactive texts and will help us faculty move students into the digital age of education.
Thank you in advance for your time and interest,
***
I went to the website and looked at the text briefly, and I wouldn’t ask a student to pay $40 for it. It’s just not that good, and for a few bucks more, a student can get an ebook edition of a name-brand textbook.
But more to the point, is it just me, or does that “test marketing program” sound like a pretext for a kickback? Awfully close to the consulting fees and conference junkets that doctors and pharmaceutical companies are always getting in trouble for.
(Of course, I’m also suspicious of the numbers. At $40 a pop, you’d need to sell 200 ebooks just to cover the $8000 kickback stipend.)
Richard Dawkins has a new book coming out, titled The Greatest Show on Earth, in which he tries to win over fence-sitters with a case for evolution.
But, is it just me, or did his last book The God Delusion (as in, if you believe in God you’re delusional) maybe alienate some of his potential audience? Or is there a big market segment of creationist atheists that I don’t know about?
Pick the one that best applies:
1. No you didn’t. The answer sounds plausible and you are a reasonably smart person so you quickly absorbed it as the correct one. So quickly, in fact, that in hindsight it now feels like you knew it all along. It is hard to have a memory of not knowing something, because way back when you did not know, you did not know that you did not know. So now you think you knew it all along, because you know it now and you don’t have a distinct memory of not knowing.
2. No you didn’t. You have previously wondered, or maybe just heard conventional wisdom that sounds like the answer you know now. Now that you know the right answer, the one you have just heard, you can search your memory and discover that you’ve thought or heard something vaguely resembling the answer before. But in fact, if you really thought about it, you could probably dig up a memory or some conventional wisdom that supports a completely different answer. Consider also that you never took a public stand, you never made it real, you never made yourself accountable for the answer you’re now claiming you knew all along. Which means that if the right answer had turned out to be completely different, it would be just as easy to say you knew that one all along instead.
3. No you didn’t. You thought it all along, but you didn’t know it all along. Your beliefs were based in your ideology or your worldview, not on any objective evidence. If you ever encountered somebody who believed differently because they had a different ideology or worldview, then at most the two of you stood there talking past each other, offering zero enlightenment to anybody approaching the issue without prejudice. Those people needed hard evidence, and you only had arguments. You didn’t know, you just thought you knew.
4. No you didn’t. You made a lucky guess. You are mentally engaged with the world, and so like all mentally engaged humans you form lots of guesses and speculations and opinions about lots of things. If you guess enough times about enough things, some of those guesses will eventually turn out to be right. That doesn’t mean you knew it all along.
5. No you didn’t. You knew the superficial version that everybody knew and that, to the scientists, was beside the point. The story you just heard or the press article you just read has omitted the scientifically interesting part. The scientists weren’t interested in the simple descriptive fact, the one that they, you, and everybody else knew all along. They were interested in how it worked or why it was the way it was.
6. Yes you did. Congratulations. You are hereby authorized to say things like, “Still no cure for cancer,” or “My tax dollars went to this?!?” Have at it.
Just back from the Association for Research in Personality 2009 conference in Evanston. Lots of interesting stuff.
One of the main themes underlying the conference was integration with economics. There were (nominally) 2 symposia on personality and economics, as well as a keynote from James Heckman.
I say “nominally” because one of the symposia was really just a bunch of psychologists using an economics panel study (the SOEP) to study personality and life satisfaction. Very interesting stuff — the size of the dataset allows them to use some very sophisticated quantitative models (though I had some quibbles with them not including systematic growth functions) — but it didn’t feel to me like it was very far outside of the mainstream personality psychology paradigm.
One of the highlights for me, though, was Heckman’s keynote address.
First, what it wasn’t: when I first heard that a big-shot economist was getting interested in personality, I assumed he wanted to use personality traits to predict economically relevant behaviors, like how people form preferences and deal with uncertainty. It sounded like a good idea, because many economists (and their psychologist cousins in decision-making) have traditionally been strong situationists and thus resistant to thinking that personality matters. And in fact, that’s what one of the talks in the actually-about-economics symposium was about (as well as some emerging work elsewhere in DM) — how personality predicts economic decisions. It’s good and important stuff, if maybe a little unsurprising as a general direction to go.
But Heckman is interested in personality in a different way. In particular, he is interested in personality development and change. His interest grows out of research showing that interventions designed to lift people (esp. young kids) out of poverty (like the Perry Preschool Study, a precursor to Head Start) are working — kids who receive early care and educational help are more likely to go on to graduate from high school, more likely to be employed full-time as adults, less likely to get involved in crime, etc. Where Heckman got involved is in understanding the mechanisms. His work has shown that these programs don’t just boost cognitive skills (that’s economist-speak for IQ) — in fact, gains in tested IQ fade a few years after the intervention. Instead, the interventions seem to be mediated by lasting changes what economists call “noncognitive skills,” which is a slightly hilarious (if you’re a psychologist) term for personality. Enduring changes in things like diligence, cooperation, positive social relationships, etc. are what seem to be driving the effects. In Big Five terms, agreeableness and conscientiousness.
Not only is it refreshing to see an economist getting interested in personality (and as a sidenote, with what I took as a very authentic interest in making it a true 2-way street), but it’s refreshing to see anybody view personality as something that is subject to change via environmental inputs. That’s a drum I’ve been banging for a while, and the field is starting to come back to that as an interest (not only or even substantially because of my drum-banging — people like Brent Roberts, Ravenna Helson, Rebecca Shiner, Dan Mroczek, Avshalom Caspi, etc. have been banging it way longer than I have). But the Q&A showed that there’ll be some resistance. One of the presenters from the life-satisfaction panel — in fact, the one who seemed somewhat resistant to including systematic growth in his models — tried to challenge Heckman on that point, suggesting (wrongly in my view) that traits are too stable to be meaningful targets for intervention.
The same questioner also raised what I thought was a more interesting point, which is, isn’t a bit creepy to be thinking about public-policy interventions designed to mold personality? Heckman’s answer was a good start though maybe a little unsatisfying. He basically said that he sees what he’s doing as empowering people to act on their preferences. (Hence the economists’ “skills” rather than “personality.”) If you’re more capable of being cooperative and diligent, you can still choose a life of poverty and crime if you want it, but you are now empowered with the wherewithal to obtain and keep a decent job if that’s what you would really prefer. This harkens back to Wallace’s (1966) abilities conception of personality, which maybe could stand for a dusting-off.
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