SciBlogs

Archive March 2010

engaging students in science through interactive learning Alison Campbell Mar 31

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This is another re-post from Talking Teaching. I know that whole interactive-engagement thing is becoming the norm in schools, but I thought it might be interesting (for teachers, in particular) to see some of the back-story :-)

After my lecture today one of the students said, "I like your lectures, they’re interactive. You make me want to come to class."

I’m really rapt about this; I’ve worked hard over the last few years to make my lectures more interactive: creating an atmosphere where the students feel comfortable & confident about asking questions; where we can maybe begin a dialogue around the topic du jour; where we can spend a bit of time working around a concept. I guess this reflects my own teaching philosophy: I’ve never felt happy with the ‘standard’ model. (I can hear some of you saying, but what’s that? I guess you could say, the stereotypical, teacher-focused model of lecture delivery.) Way back when I was a trainee secondary teacher, my then-HoD was very big on me talking & the kids writing; we had to agree to disagree… Anyway, as time’s gone on my teaching’s become more & more ‘research-informed’, in the sense that I’ve increasingly delved into the education literature & applied various bits & pieces to what I do in the classroom. Anyway, to cut what could become a very long story a bit shorter, there’s good support for the interactive approach in the literature.

A recent, & prominent, proponent of getting students actively involved in what goes on in the lecture theatre is Nobel laureate Carl Wieman, who gave a couple of seminars at Auckland University & AUT late last year. His talks were titled Science education in the 21st century – using the insights of science to teach/learn science. I wasn’t lucky enough to go there, but the next best thing – the powerpoint presentation he used - is available on the Ako Aotearoa website. The theme of the presentation is that if we really want our students to learn about the nature of science, then we need to encourage them to think the way scientists do. This means giving them the opportunity to do experiments (& not the standard ‘recipe’-type experiments so common in undergraduate lab manuals, either), to ask questions, to make mistakes. Anyway, the presentation’s great & I thoroughly recommend having a look at it (hopefully that link will work for you).

But my active thinking about interactive learning goes back rather longer – I think I first really began to consciously focus on it when I was re-developing the labs for our second-year paper on evolution. Teaching evolution the ‘traditional’ way just doesn’t work; it does little or nothing to address strongly-held beliefs & misconceptions, mainly I think because the standard transmission model of giving them ‘the facts’ doesn’t let students engage with the subject in any meaningful way. A couple of papers by Passmore & Stewart (2000, 2002) helped me to focus my thoughts & I believe engendered some significant changes (for the better!) in the way our labs were run.

Last year I came across a paper by Craig Nelson, which presents strategies for actively involving students in class. While he talks primarily about teaching evolution, all the methods he describes would surely result in teaching any science more effectively: engaging students with the subject, helping them to gain critical thinking skills, & in the process confronting their misconceptions & comparing them with scientific conceptions in the discipline. (As part of this he gives a reasonably extensive list of resources and techniques to support all this.) Along the way Nelson refers to a 1998 paper by Richard Hake, who looked at the effectiveness of ‘traditional’ versus ‘interactive’ teaching methods in physics classes.

As the title of Hake’s paper suggests, his findings are based on large numbers of students, in classes on Newtonian mechanics. He begins by noting that previous studies had concluded that ‘traditional passive-student introductory physics courses, even those delivered by the most talented and popular instructors, imparted little conceptual understanding of [the subject].’ Worrying stuff. Hake defines interactive-engagement teaching methods as ‘designed at least in part to promote conceptual understanding through interactive engagement of students in heads-on (always) and hands-on (usually) activities which yield immediate feedback through discussion with peers and/or instructors.’  He surveyed 62 introductory physics classes (over 6000 students), asking the course coordinators to send him pre- & post-test data for their classes, and asked, ‘how much of the total possible improvement in conceptual understanding did the class achieve?’ Interactive-engagement teaching was streets ahead in terms of its learning outcomes for students.

Nelson argues that such teaching is also far more effective in assisting students in coming to an understanding of the nature of science. The ‘problem’, of course, is that teaching for interactive engagement means that you have to drop some content out of your classes. It just isn’t physically possible to teach all the ‘stuff’ that you might get through in a ‘traditional’ lecture while also spending time on engaging students in the subject & working on the concepts they find difficult (or for which they hold significant misconceptions). In fact, Nelson comments that limiting content is perhaps the most diffiucult step to take on the journey to becoming a good teacher. He also cites a 1997 study that found that ‘ introductory major courses in science were regarded as too content crammed and of limited utility both by students who continued to major in science and by equally talented students who had originally planned to major in science but later changed their minds.’ This is a sobering statement - & perhaps it might be useful in countering the inevitable arguments that you can’t leave things out because this will leave students ill-prepared for their studies in subsequent years… But then, what do we as science educators really want? Students who understand what science is all about, & can apply that understanding to their learning, or students who can (or maybe can’t) regurgitate ‘facts’ on demand for a relatively short period of time but may struggle to see their relevance or importance? I know which one I go for.

Hake, R. Interactive-engagement versus traditional methods: a six-thousand-student survey of mechanics test data for introductory physics courses. American Journal of Physics 66(1): 64-74

Nelson, C. (2008) Teaching evolution (and all of biology) more effectively: strategies for engagement, critical thinking, and confronting misconceptions. Integrated and Comparative Biology 48(2): 213-225

Passmore, C. & J. Stewart (2000) “A course in evolutionary biology: engaging students in the ‘practice’ of evolution.” National Centre for Improving Student Learning & Achievement in Mathematics and Science Research report #00-1: 1-11.

Passmore, C. & J. Stewart (2002) “A modelling approach to teaching evolutionary biology in high schools.” Journal of Research in Science Teaching 39(3): 185-204.

a new hominin from siberia? Alison Campbell Mar 29

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ResearchBlogging.org

The latest edition of Nature carries an item that raises the possibility of another new – & recent – new hominin species, this time from Siberia (Krasuse et al., 2010). A few years ago, when the story about Homo floresiensis first broke, I remember commenting to my classes that it was probably only a matter of time until another recent relative popped up. After all, all the evidence to date shows that our family tree is much bushier than scientists used to think – when I was in high school that tree was presented as essentially linear in nature. But Siberia?

My mother used to say (when asked by importunate students how old she was), ‘I’m as old as my little finger & older than my teeth.’ In the case of this possible new hominin, that would make her very old indeed. The new find consists of a finger bone – the tip of a pinky, in fact – and the mitochondrial DNA (mDNA) extracted from it. (For ‘pinky’ read ‘distal manual phalanx of the fifth digit’…)

The bone was found in Denisova Cave, which is in the Altai mountains of Russia & which has been occupied (on & off) by hominins for around 125,000 years. The finger bone wsa found in a layer of sediment dated at 48-30,000 years ago, & which has also yielded a range of other artefacts. Krause & his team decided to see if they could extract & sequence mtDNA from the bone; they felt this was at least a possibility as the cool conditions in the cave are better for long-term preservation of DNA than the tropics. They expected that – if their extraction was successful – the bone would be from a Neandertal or a modern H.sapiens individual, on the basis of the tool assemblages from the site and the geographic range of both species.

Using 30mg of powdered finger bone (this sounds like something Macbeth’s witches would have liked…), the research t3eam were able to extract & sequence mtCNA. They then made a section extract & compared the two sequences: they turned out to be identical. The team hen checked that their sequences came from a single individual (if one bone yielded evidence of more than individual, then there could be questions about contamination). It did.  The degradation patterns of all the mtDNA fragments were also typical of ancient, not modern DNA: further evidence that the sample was not contaiminated.

The next step was to compare the mtCNA from the Denisova cave individual with sequences from  modern human mtCNA, a sample from an individual who lived in late-Pleaistcene Russia, Neandertal mtCNA, and sequences from a chimp and a bonobo. There must have been a certain amount of excitement in the lab when the results of this came out – becaue the Denisova hominin’s DNA had nearly twice as many idfferences from modoern DNA as that of Neandertals (385 base-pair differences for Denisova/sapiens compared to 202 for the Neandertal/sapiens comparison). 

This suggests that the most recent common mtCNA ancestor for modern humans, Neandertals, & the Denisova individual lived about a million years ago.There’s a certain amount of uncertainty around the dates, but nonetheless this is a long time ago. Krause’s team comment that  ‘the divergence of the Denisova mtDNA lineage on teh order of one million years shows that it was distinct from the initial radiation of H.erectus that first left Africa 1.9 million yeers ago.’  Remember, though, that we really need DNA (ideally both mitochondrial & nuclear) from more complete skeletal remains before it’s possible to ‘place’ the Denisova hominin with any degree of confidence.

Getting back to my original comment – it’s entirely possible that multiple hominin lineages co-existed in this part of the world as recently as 40,000 years ago. If the Denisova individual is confirmed as a new species, then it would have had both Neandertal & anatomically-modern humans as close neighbours in space & time. The apparent temporal overlap of floresiensis and sapiens in Indonesia may not have been an isolated event, and our family tree will then be even bushier than my teachers ever imagined :-) 

Krause, J., Fu, Q., Good, J., Viola, B., Shunkov, M., Derevianko, A., & Pääbo, S. (2010). The complete mitochondrial DNA genome of an unknown hominin from southern Siberia Nature DOI: 10.1038/nature08976

humour with a serious message – the vaccine/autism ‘debate’ Alison Campbell Mar 29

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From time to time the ‘debate’ around vaccinations re-surfaces in the headlines. A number of other NZ bloggers have addressed this (here, & here, for example). It’s a much hotter topic as in the US, where a number of high-profile ‘anti-’ groups keep vaccines in the public eye for all the wrong reasons. 

Don’t get me wrong – I have an enormous amount of sympathy for people whose children have become ill some period of time after receiving a vaccine. But apparent correlations in time do not equate to causation, a fact that lies at the heart of this issue and makes me wonder how effective we are at communicating about the nature of science to the community at large.

This is a real concern. Following Andrew Wakefield’s now thoroughly discredited claims about a link between the MMR vaccine and autism, vaccination rates in the UK dropped to the point that measles in particular is again widespread in some communities. And while it can be a ‘trivial’ illness in most children, measles carries a real risk of serious illness & in some cases death (a risk that is several orders of magnitude higher than the risk of severe adverse effects from the vaccination itself).

Anyway, a very recent Downfall parody takes aim at the US opponents of vaccination – most of the names mentioned in this clip are those of prominent players in this group. The ‘Paul Thoresen’ mentioned first up is a scientist associated with a couple of research groups who may or may not have been involved in a misappropriation of funds – whether or not this is true has absolutely no bearing on the quality of the research done by those groups, something that seems to have escaped the ‘anti-’ commenters.

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PS readers might also be interested in this post at ScienceBased Medicine, which examines some of the ‘vaccines don’t work’ claims.

 

hey hey it’s friday – and the darwin awards are out :-) Alison Campbell Mar 26

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The Darwin Awards have been around for a few years now. They’re given to those people who – by some act of breath-taking stupidity – have removed themselves from the gene pool. (Though you could argue that most of the recipients should be excluded due to age….)

 

 Humorous Pictures

The (definitely posthunous) winner of this year’s awards:

When his .38-calibre revolver failed to fire at his intended victim during a hold-up in Long Beach, California, a would-be robber did something that can only inspire wonder. He peered down the barrel and tried the trigger again. This time it worked.

cats

how not to do science: the scole experiment Alison Campbell Mar 23

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I listen to quite a lot of podcasts. Lately I’ve been listening to more than usual. I’ve had the flu (I’m assuming that’s what it was, since colds tend not to come with fever, chills, & sore joints) & listening to stuff was easier than reading. Anyway, I digress.

One of my current favourite podcasts is Brian Dunning’s Skeptoid.com. – excellent primers in critical thinking, nicely presented, & not too long. One of these concerned the ‘Scole experiment’ – supposedly an excercise in which scientists tested the claims of mediums (people claiming to communicate with the spirit world) and  – gasp! – found the claims justified. I’ve been interested in claims about the paranormal ever since reading (& re-reading, multiple times) Martin Gardner’s book Science: good, bad & bogus.

The Scole experiment – named for the village in England where it was carried out – was a series of seances led by 6 mediums and investigated by 15 members of the Society for Psychical Research. Involving large numbers of investigators & psychics, It supposedly provided evidence of the existence of ‘spirits’: lights moving about in a darkened, closed room; photographic images appearing on film that had previously been sealed into secure containers, physical contact with invisible entities; tables lifting off the ground, & voices coming out of nowhere. Nor, it’s claimed, was there any evidence of fraud.

So, evidence that there is an afterlife, & us sceptical sorts should start to revise our worldview? Not so fast, says Dunning.  When you come to look closely, the Scole experiment turns out to be a very good example of how not to do a scientific investigation.

I know that if I was going to undertake an investigation of psychic claims, about the first thing on my list would be to put in place various controls & restrictions, thus minimising the opportunity for any possibility of fraud. Things like cameras, motion sensors, venues thoroughly checked beforehand. Amazingly, Dunning tells us that this was not what happened in the Scole study. Here, the mediums set all the rules, thus effectively ruling out the possibility of this being a serious scientific examination of the proceedings. In fact, it appears that the investigators did everything that the mediums asked of them – Dunning describes them as acting as an audience, rather than researchers. Thus:

  • the psychics were effectively free to move around during each seance (no hand-holding), and thus the investigators weren’t able to exclude the possibility of the phenomena they witnessed being generated by the performers themselves.
  • they banned any use of still or video cameras – & this included infra-red & night-vision equipment. (One has to wonder why this was the case – if the seance was genuine, this technology would surely be no threat..)
  • the box into which unexposed films were locked was supplied, not by the investigators, but by the psychics. What’s more, one of the investigators wrote that he was able to easily open the box in the dark… Films placed in boxes supplied by the ‘researchers’ never developed any images, a fairly suggestive finding.
  • the seances were carried out in a room provided by the mediums, not the researchers.
  • and – despite the fact that the Scole performances have been hailed as proof positive of an afterlife – there’s been no follow-up at all.

This complete lack of any serious controls and experimental protocols means that we can’t take the study’s findings seriously. And it does bring to mind a couple of comments from Gardner’s book. One has to do with the apparent hypersensitivity of psychic phenomena to any sort of critical examination. The other was Gardner’s statement (I think originally made by prestidigitator & debunker James Randi) that scientists are perhaps the easiest audience to fool  if you’re a magician or psychic – because they don’t expect anyone to be setting out to deliberately pull the wool over their eyes…

I do enjoy my regular Skeptoid fixes :-)

belief & knowledge – a plea about language Alison Campbell Mar 19

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I suspect that for many of my first-year Biology students, the sheer weight of new terms they come across is perhaps the most daunting thing about the course. In some ways learning biology is rather like learning a new language – with several thousand new words swamping the page (& the brain) over the course of a 3-year degree.

But there’s more than just the new words – there’s the meaning of the words to come to terms with. This is the focus of Helen Quinn’s 2007 paper, Belief and knowledge – a plea about language. There are many words where their meaning to a scientist may be quite different from what they mean to a lay person. Quinn feels, & I agree, that some words ‘are the root of considerable public misunderstanding about science: belief, hypothesis, theory and knowledge.’

‘Belief’ isn’t really a word that sits well with science. It has a couple of meanings in everyday speech. As Quinn says, it can be ‘an article of faith’ ie religous belief. Or – conversely – in the phrase ‘I believe he is coming at 5pm’, you get the meaning ‘but I’m not really sure.’ So how are we to take those news stories that begin ‘Scientists believe’? A statement like ‘most biologists believe in evolution’ could be used to claim that evolution is as much faith-based as organised religion. (I tell my students that I don’t ‘believe’ in evolution, but accept it as the best available current explanation for life’s diversity. This can engender some interesting discussions…)

But what the statement ‘most scientists believe’ means – to scientists – is that the majority of scientists are in agreement that the weight of evidence favours a particular interpretation, & that for now there’s no evidence to contradict that interpretation. Quinn suggests we should say ‘scientific evidence supports the conclusion that…’ I like this – it leaves open the possibility that this conclusion could change, if sufficient evidence to the contrary comes to light. Which is a much better reflection of the nature of science: that its conclusions are subject to change if the evidence demands it. Unfortunately there tends to be a perception that scientific ‘facts’ don’t change. (Also unfortunate is the fact that if scientists do change their interpretation of the data, they’re accused of not really knowing what they’re talking about by those who don’t understand how science operates. Sometimes I think we just can’t win!) Like Quinn, I feel that as scientists we shouldn’t be using the ‘b’ word – it gives the appearance that science is ‘just another belief system.’

‘Theory’ is another word that means different things to different people. ‘I’ve got a theory about that’ really means, ‘I’ve got a hunch or an idea, a guess.’ But to scientists ‘theory’ means a well-established explanation for a large body of data: the theories of relativity, plate tectonics, evolution… These are definitely not guesses (nor are they belief systems!), but comprehensive explanations that have strong predictive power & have been tested time & time again. They are also incomplete, but that again is the nature of science. Scientific theories may well be modified if new evidence comes to hand: Newton’s laws are an example. (Quinn notes that Newton’s laws still hold, under certain well-defined condtions – they’re weren’t just thrown out when Einstein & special relativity came on the scene.)

To finish, it’s worth repeating Quinn’s description of how scientific theories are developed, because this is a valuable description of how science operates and what sets it apart from ‘other ways of knowing’:

When we seek to extend and revise our hypothetical frameworks, we make hypotheses, build models, and construct untested, alternate, extended theories. These last must incorporate all the well-established elements of prior theories. Experiment not only tests the new hypotheses; any unexplained result both requires and constrains new speculative theory building – new hypotheses. Models… play an important role here. They allow us to investigate and formulate the predictions and tests of our theory in complex situations. Our theories are informed guesses, incorporating much that we know. They may or may not pan out, but they are motivated by some aspects or puzzles in the existing data and theory. We actively look for contradictions. 

 

H.Quinn (2007) Belief and knowledge – a plea about language. Physics Today January 2007: 8-9

how biology teachers can respond to intelligent design Alison Campbell Mar 17

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Creationism is a recurring issue for teachers of biology. It can come in many forms (eg young-Earth creationism, old-Earth creationism, & so on) but – despite what many ‘IDers’ would say – its most recent incarnation is as intelligent Design ‘theory’, or IDT. (I use the quote marks advisedly; Intelligent Design doesn’t offer any evidence that can be explained by a coherent scientific theory, instead preferring to generate a false dichotomy between IDT and evolution: if evolution is wrong about ‘x’, then IDT is correct.) While IDT received a resounding defeat in the Dover trial of 2005, it continues to be promoted around the world as a ‘scientific’ alternative to evolution.

Anyway, a colleague has just sent me Jim Mackenzie’s paper, How biology teachers can respond to Intelligent Design, which I thought I’d talk about here. As Mackenzie says, a significant number of authors have already argued convincingly that IDT is bankrupt as far as scientific theories are concerned. He proposes several strategies that science teachers can use in dealing with attempts to introduce IDT into their classrooms, and comments that it’s possible to use these with younger children. I think this is particularly useful given that the 2010 NZ science curriculum makes evolution an organising theme for biology (aka the ‘Living World’) from the earliest years of primary schooling. Mackenzie’s strategies are drawn from a case dating back more than 20 years, from an attempt to mandate the teaching of creation ‘science’ – surely an oxymoron - in Arkansas schools. I found this a little surprising given the more recent Dover case, but then it is all creationism under the skin, despite attempts by various ID proponents to claim otherwise.

Just as in Dover, the Arkansas attempt to insert creationism into school curricula claimed that there was strong scientific evidence in support of doing so. The case went to court. In his decision, Judge Overton noted that teachers given the job of producing a curriculum for teaching biology from a creation ‘science’ viewpoint could not find any scientific articles in its support. Not one. There was simply no creationism research available to make this a viable alternative to evolution.

Mackenzie suggests that teachers wishing to show that ID is outside science should use a ‘wide’ definition of science. He argues that definitions of science allowing only ‘natural’ (as opposed to supernatural) explanations are too narrow & risk being accused of excluding ‘too much’. He then goes on to state that this definition is ‘inoperative [in any case] because once an explanation comes to be incorporated into science it is seen as natural and matrialist, even if had previously seemed not to be’, & gives Newton’s theory of gravity as an example. Gravitational theory was originally viewed as magical or occult, but because it allowed accurate predications, was eventually accepted. Well & good, but the suggestion that if scientists accepted IDT as scientific, its arguments might be accepted as Newton’s were seems to me to be drawing a long bow. There are many reasons why scientists have already rejected IDT as non-scientific, as Mackenzie himself admits. It is, however, useful to emphasise, as he does, that even when the bar of what is considered ‘science’ is set very low, IDT fails to clear it. There is still no ID research published in scientific journals that clearly presents evidence in support of ID (attempting to show that evolution can’t explain something, & claiming that as evidence ‘for’ ID, doesn’t count.)

The second strategy is to make it clear that religion is not the enemy of science. Part of the reason for excludng creationism from US schools lies in the constitutional separation of religion and the State. Show a particular standpoint is religious & it can’t be taught in schools in the USA. That’s not the case in many other places, & here in NZ it’s possible to present religious instruction in state schools, provided parents have the opportunity to opt out. The problem here, as recent mailouts to science departments have shown, begins when attempts are made to present a particular religous viewpoint in the guise of science. (I thought the Ministry of Education’s response to this was a bit of a cop-out: saying that parents can withdraw their children from religous education ignores the fact that this stuff was being sent to science teachers with the obvious hope that it would be incorporated into science classes.)

Nonetheless this is a key point – there’s nothing to be gained, if the question of creationism is raised in a science class, in ridiculing religion. Religious beliefs are often strongly held & denigrating them won’t do anything to convince a student (or their parents) of the validity of evolution & is more likely to set them at loggerheads with the teacher. A more useful strategy might be to point out that major religious leaders – including the last Pope – have indicated that there is no conflict between faith and science on this matter.

Mackenzie’s third key statement is that ‘science teachers should trust their own expertise’ – and this means bringing that expertise to the fore. We’re all aware (or we should be!) that in science theories are constantly being tested, added to, modified. There’s much about the current state of evolutionary biology that Charles Darwin would never have recognised: Mendelian genetics, the concept of genetic drift, punctuated equilibrium, horizontal gene transfer… All these new ideas have been tested empirically & subsequently become an established part of evolutionary biology (& after that, they make it into the textbooks). There’s a very strong case to be made for us to talk about all this with our students, rather than treating it all as a fait accompli. As Mackenzie says, ‘[t]here may always be new ideas, new evidence, and every scientific conclusion is open to revision.’ How better to give students an understanding of this key aspect of the nature of science?

And finally, he suggests that ‘alternative theories should not be excluded.’ Well, I’m fine with that, as far as it goes – & as long as we are talking about ‘theory’ in the scientific sense. But what Mackenzie really means is that, faced with a request to include ID in the classroom, teachers should respond that they would intend to look at a wider range of alternative perspectives . This of course assumes that teachers are aware of that range, and are confident in their ability to explain why they do not constitute a scientific explanation for life’s diversity. And that there is actually time in the full-on classroom day to do this approach justice.

J.Mackenzie (2010) How biology teachers can respond to Intelligent Design. Cambridge Journal of Evolution 40(1): 53-67. DOI: 10.1080/03057640903567039

overrun with creepy-crawlies? maybe not… Alison Campbell Mar 16

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I blog a fair bit about the way science stories are (mis)represented in the press. And when I do, I always wonder what the original press release (from the intitution to the media) would have been like. Now Ben Goldacre’s posted an excellent item on one such release.

The release in question came from a UK pest control firm, & it contained ‘data’ that seemed to show alarmingly high levels of pest infestation on London public transport. (Or, in the case of dust mites, surprisingly low. Only 500 of these tiny critters in a whole railway carriage?) Things like cockroaches, bedbugs, fleas. (Apparently bedbugs are raising their nasty little heads in New Zealand – not something I’d want to see gain a significant foothold here!). Cue a number of rather hysterical media articles.

Ben has done his usual thorough job of investigating this one. And he found – that the company did no studies whatsoever of in-service public transport vehicles. None. Zero. Zilch. Their scary figures were based on a model, which made a whole lot of unsupported & highly unlikely assumptions. As Ben hasn’t been able to track down the original release, we can’t be certain of its contents. But I have to say – to pretend some sort of scientific support for the numbers sent out to the media is to misrepresent what was done as good science. And that does none of us any favours.

how do we teach students to question what we say? Alison Campbell Mar 14

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This is a re-post of something I’ve written for Talking Teaching. I’ve reproduced it here because I think the notion of teaching things like critical thinking & the nature of science are just as relevant here as they are in a discussion about teaching itself.

I’ve just been reading a post by Tim Kreider, over at Science-Based Medicine. Tim’s talking about the learning experiences of medical students, but a particular phrase caught my eye. I”m reproducing it here because I think it can be applied much more widely: students are in the habit of transcribing and commiting to memory everything uttered by the professors who grade them.

I’ve seen this happen myself. I remember talking with a class about fungi & saying that while most fungi are saprophytes (consuming dead material), some are predatory. And they all (well, all those I could see, anyway) wrote this down unquestioningly. ‘Hang on a minute,’ I said; ‘does this sound likely to you?’ They agreed that no, it didn’t really, it didn’t match with what they already knew about fungi. ‘Well then,’ I said; ‘why didn’t any of you call me on it?’ ‘Because,’ they said, ‘you wouldn’t tell us anything incorrect, would you?’ Which showed a touching faith but also a worrying lack of willingness to question things that didn’t sound right.

(Just as an aside: This was amply demonstrated one year when my class was sitting a lab test. One of the questions asked students to label a section of plant tissue, selecting their labels from a list that I provided. It happened to be April 1st – so I included the word ‘aardvark’ in that list. Rather worringly, about 30% of the class used it for a label – & when asked why they said well, it didn’t sound right, but they just knew I wouldn’t have used a word that didn’t belong… And not one of them questioned it at the time.)

Now, in his SBM post, Tim makes the point that med students in their pre-clinical training have to learn so much content that there isn’t a lot of room for rigorous skepticism (but make no mistake, he’s still arguing of the need to teach critical thinking). And I agree, there is factual content that I want my students to be able to remember (& my colleagues teaching at 2nd-year would like it too!) But at some point we must surely also want our students to develop a healthy skepticism: the ability to think critically about what they’re hearing & learning.  And I certainly don’t like the idea that my science students might regard me as infallible. Not least because that’s not a particularly good model for what science is like. They need to know that scientists can & and do make mistakes, get things wrong, interpret data in ways that subsequently (in the light of further data) turn out to be inaccurate. And they need to feel confident that it’s OK to ask questions. The thing is, how best to get this across?

Speaking for myself, I’m a firm believer in modelling this for my students. If I’m asked a question to which I don’t know the answer, I’ll tell them so, up front. But then I’ll say, but I can hypothesise about this – here’s what the answer might be, & here’s my evidence for thinking this. (If the classroom has web access – & most of ours do these days, we’ll often go on to check what I’ve said on the spot.) If it turns out that I’m wrong (which happens quite a lot, then that’s fine, & we’ve all learned something new.

Plus, I actively encourage questioning during my lectures. (Pop quizzes & concept maps are good for encouraging the sort of conversations that lead to this.) Sure, I mightn’t get through as much content as if I didn’t do this, but the students’ learning experience is surely going to be a better one if they can follow up on things on the spot. And hopefully they learn from this that it really is OK to ask questions :-)

And – I’m all for telling stories. How better to help students learn about the nature of science than to use a narrative approach that lets them see how scientists viewed the world at some past point in time, & how science has led to a change in - or a reaffirmation of – that perspective?

cross-species hanky-panky Alison Campbell Mar 12

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My first-year students & I are currently studying plants. This is actually something of a balancing act from my perspective as a reasonably large proportion of the class didn’t study the ‘diversity in plant structure & function’ standard back in year 12 (or don’t remember doing so), so I’ve got to bring them up to speed without boring the others.

Anyway, when we get on to talking about flowering plants, one of the topics is adaptations for pollination. Some flowering plants (eg grasses) simply shed their pollen to the wind, but for many successful pollination has required the establishment of a plant-animal relationship. And some of those involve some very kinky activity indeed – the animal ‘vector’ comes to a flower, not for a nectar reward, but because in its eyes the flower looks like a member of the opposite sex…

And thanks to PZ, who always finds these things first!

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