how do kids learn about dna?

My significant other is forever telling me that Facebook is a total time-waster. Sometimes I do tend to agree – but also, one can Find Out Stuff! Like the study I’ve just heard about via Science Alert, on how children get information about genetics and DNA – things we might regard as being in the ‘too hard’ basket & so best left for senior high school students to grapple with. That grappling begins in year 11, when one of the NCEA Level 1 Science standards asks that students be able to “demonstrate understanding of biological ideas relating to genetic variation”.

Is that too late? Jenny Donovan and Grady Venville suggest that it is, arguing that with the rapid growth of knowledge in and applications of molecular biology,

[citizens] of the future will be called upon to make more decisions, from personal to political, regarding the impact of genetics on society. ‘Designer babies’; gene therapy; genetic modification; cloning, and the potential access to and use of personal genetic information are all complex and multifactorial issues. All raise ethical and scientific dilemmas.

They give the example of jury trials, where jurors may hear quite complex information about DNA and be asked to consider this in coming to a verdict, and note that people may have acquired a range of misconceptions around DNA from sources such as the popular program CSI and its various spin-offs.

Children, for example, have a lot of opportunity to hear about genes, DNA, & their uses well before we start formally teaching these concepts at school. Donovan and Venville already knew (from their own previous research) that by the end of their primary schooling many students were already developing misconceptions about genetics; for example, the idea that ‘genes and DNA are two totally separate entities.’ This time, they wanted to examine the impact of the mass media on children’s conceptions (& misconceptions) around this subject. The misconceptions part is particularly important because misconceptions, once formed, can be extremely persistent – affecting learning into the tertiary years.

Using a combination of interviews and questionnaires about media use, the researchers found that their subjects (children aged 10-12) spent around 5 hours a day using various media (TV, radio, print media, movies, & the internet), with most of that being watching television. This included crime shows, and the children felt that they gained most of their ‘knowledge’ of genetics from TV. Donovan & Venville chose to question children from this age group because, with falling numbers of Australian students taking science subjects in upper secondary school, ‘exposure to genetics may be their sole opportunity to develop scientific literacy in this field’ – where ‘scientific literacy’ encompasses literacy both within and about science.

So, what did they find out?

Most children (89%) knew [about] DNA, 60% knew [about] genes, and more was known about uses of DNA outside the body such as crime solving or resolving family relationships than about its biological nature or function. Half believed DNA is only in blood and body parts used for forensics.

Very few – only 6% – knew that DNA and genes were structurally related. Around 50% of the children surveyed felt that DNA & genes are found in only some tissues & organs. (I was half expecting them to say that DNA is found only in genetically-modified organisms – with GMOs in and out of the news, it’s odd that this didn’t come up.) And 80% of them felt that TV was ‘the most frequent source of information about genetics (with teachers confirming that the subject hadn’t been taught at school). As a result of these findings, Donovan & Venville argue very strongly that instruction in genetics should take place much earlier in students’ time in school, noting that other researchers suggest that

giving students opportunities to revisit science ideas and build deeper understanding over time, enables them to grasp and apply concepts that typically are not fully understood until several years later… [and that] students need to be exposed to background knowledge from early ages in order for them to make sense of what they absorb from the world around them.

So, if kids are going to watch programs like NCIS, CSI, and Bones on a regular basis, then maybe early teaching around genetics concepts could use

lively discussions around what they have seen and heard about genetics in the mass media [as this] may ultimately help children to make informed decisions in their future lives.

An interesting suggestion – and one which reinforces yet again how important proper resourcing and support of science teaching are, if we are to develop real literacy in and about science.

J.Donovan & G.Venville (2012) Blood and bones: the influence of the mass media on Australian primary school children’s understandings of genes and DNA. Science & Education (published online 23 June 2012, doi: 10.1007/s11191-012-9491-3

more on active learning in the biology classroom

At the moment I’m up in Auckland at Scicon (the national secondary science teachers’ conference. There’ve been some great presentations, including a lovely on on bioluminescence by fellow sciblogger Siouxsie Wiles (did you know that our very own NZ glow worms mate for hours & then die of exhaustion? Or that 4500 people die oftuberculosis every day? Yes, there really is a link to bioluminescence there.). I gave mine this morning & could then focus on enjoying everything else that’s going on.

My talk was about the ‘flip teaching’ idea that I wasintroduced to by Kevin Gould, &  which I’ve written about previously. Actually it wasn’t really a talk, as I simply gave a bit of background & a summary of some of the recent research, & then asked participants to do the activity themselves. At which point everyone got involved & the chatter started – & it was hard to get them to stop at the end! But we managed a show-&-tell & some great discussion before our time was up.

One of the things people really picked up on was something I really hadn’t thought much about: using it to underpin development of students’ writing skills. That’s in addition to conceptualising, discussing & drawing their organism: there are also things like annotating that diagram,  & writing descriptive paragraphs about the various ideas they’ve used. Really integrated learning!

And there’s also the issue of creativity – exercises like this are an excellent way to show students that science can be creative, & that this creative side is an important part of ‘doing’. science :-)

writing rubrics shouldn’t be an imposition

I had an interesting conversation with a couple of colleagues yesterday, concerning the value of rubrics. I write them routinely (must be my background as an examiner at the national level), but my friends really didn’t seem to see the point. ‘You just get a feel for what’s a good essay & a bad one,’ they said, ‘and anyway we don’t have time to write a whole bunch of model answers; it’s quicker just to get in there & start marking. Besides, you can never include every possible answer. ‘ ‘And,’ they said – we were talking about rubrics for someone else to use in marking – ‘it’s far more consistent just to do it all yourself.’

I do agree that some essays spring out as being absolutely wonderful (the very first exam script I marked yesterday was a case in point: a beautifully-constructed answer to a ‘design-a-plant’ question) while occasionally you’ll also come across one that makes you feel like banging your head on the desk. But how can you be sure that you’re treating them consistently? After all, with a big class you’ll likely be marking exam scripts for several days, & your concentration & energy levels are going to vary over that time! Constructing a marking rubric before beginning the marking task will help with that.

It doesn’t have to take a heap of time either, because a rubric is most definitely not a detailed model answer. (I’ve copy-pasted one of my own from last year’s ‘cellular & molecular biology’ final exam – itself adapted from an earlier Schol Bio exam – at the bottom of this post **.) The ones I use identify the key concepts/ideas that I’m looking for, plus usually a non-exclusive list of possible examples, & the mark weighting. I’ll often change them when I’m actually doing the marking, if students are writing good answers that include options I hadn’t considered (yes, it happens!). If my team’s marking term essays, then such changes are made in consultation – something that helps ensure consistency across markers. Moderation helps there, too – check-marking a couple of papers from each of the top, middle, & bottom cohorts will quickly show if another team member’s marking is consistent with mine.

And that ability to ensure consistency is important – not only so that students can be sure that their work has been marked fairly and well, but also so that if an individual’s marking is ever questioned (let’s say, for example, that a student’s not happy with their final grade & opts for a re-mark of their year’s work), then the rubrics can be made available to a new marker to use.

I should add that, when I set the term essay questions (which I really must do Very Soon Indeed), I write the rubrics at the same time & both are available to students from the beginning of the semester.You might ask, why? And I’d say, why not? Having a good rubric to hand helps the students in so many ways, in terms of learning how to structure an essay & an argument, & also in learning some of those key critical thinking skills: they need to assess the information they’re gathering & decide what’s relevant & what’s not, & how to pull it all together. The last thing I want to be reading is a series of brain dumps, where a student’s simply written everything they know in a rather incoherent manner. Nor do I have time to help each individual student who does that sort of thing – & we used to see quite a few, before I started using rubrics in this way. Providing a marking scheme in advance saves both parties time & helps the students acquire some desirable skills. (The old adage about leading horses to water still applies, alas!)

I hasten to add that the essay rubrics don’t include information on content in the way that an exam marking rubric does! I’ve added an essay example below as well ***, so you can compare the two :-)

 

**Final exam question & rubric

Mammoths are closely related genetically to African elephants and similar to them in body mass. Although mammoths became extinct around 20,000 years ago, a number of individuals have been found frozen in the Arctic permafrost. Some scientists believe that it is technically possible to clone mammoths from cells in these frozen bodies, thus ‘bringing mammoths back to life’ and producing a self-sustaining wild population.

Describe how this cloning could be done – including identifying a likely species to provide surrogate mothers – and discuss the genetic and evolutionary issues associated with such work. You could consider the impact of genetic drift, inbreeding and inbreeding depression on such a population of mammoths, and their long-term prospects for survival.

Describe how cloning could be done: Basic description of method (3 mks) Identifies African elephant as likely surrogate (1 mk) Explains reason for this choice (2 mks)	6
Genetic drift Gives definition (2) Describes impact on population gene pool (2)	4
Inbreeding Gives definition (2) Describes impact on population gene pool (2)	4
Inbreeding depression Gives definition	2
For all three of the above, Discusses impact on population’s prospects for long-term survival from a genetic perspective. Could include eg effects of decline in heterozygosity, decreased ability to respond to evolution of pathogens/parasites, decreased fecundity	4

***Term essay question & rubric

On the basis of fossil remains, Neanderthals are viewed as a sister species to Homo sapiens. Now new data from molecular biology are changing our understanding of human evolution.

Discuss the validity of the biological species concept in the light of recent molecular data from sapiens, neandertalensis, and the Denisova hominins.

 

Introduction – should include a definition of the biological species concept, and the nature of ‘sister species’.	/4
Briefly explain why Neandertals and modern humans have previously been viewed as sister species. How does this relate to the ‘out-of-Africa’ hypothesis for modern human origins?	/3 /2 /5
Outline the results of comparing neandertalensis and sapiens genomes, and the implications of these results.   What is the significance of the Denisova remains? (This should refer to the DNA analyses and their results.)	/3 /2 /5
How well does the biological species concept apply to Neandertals and modern humans, in the light of these findings? What are the implications for the ‘out-of-Africa’ hypothesis?	/6
Mark for content of essay	/20

in the lecture theatre – but definitely not giving a lecture!

Today’s class was a real experiment for me, & although I try lots of different things in my classes, it was also a step outside my normal comfort zone. (But hey! life would be a bit boring if we always stayed safely inside that zone!) Why? Because I put into practice an idea I stole from my friend & colleague Kevin Gould (who also very kindly let me use the resources he’d developed): today was ‘design-a-plant’ day, & probably to anyone looking into the lecture theatre during the first 30 minutes or so it would have looked as if chaos definitely ruled.

Last Friday I gave everyone an information sheet: descriptions of the features of leaf, stem & root that you might see in plants adapted to different environments. Today I trotted off to the lecture room with a box full of overhead transparency sheets, overhead pens, & printed scenarios (descriptions of a particular environment). The lecture theatre was already full – everyone had come ahead of time! This definitely wasn’t usual (it’s not that they normally trickle in late, but we’re talking seriously early) – obviously they were expecting something special. Gulp.

So I put up these slides:

then once they’d sorted out their groups I dished out pens, transparencies, scenario sheets (& copies of the info sheet for those who’d forgotten them), & away we went on a mutual journey of discovery. After all, this wasn’t my idea & I had no idea how it would really work out.

Well! The class erupted into happy, productive noise. I know it was productive because while they talked, argued, explained & persuaded, I circulated, listened in, & answered the occasional question. Those with computers had them open – looking up information related to their scenario. (Next time someone asks a question that I can’t answer on the spot, I’m jolly well going to get someone else to google it for me!) They drew, & altered their drawings, & drew some more. The original 20 minutes stretched towards 30, & still they were focused on what they were doing. I was almost sorry to interrupt :-)

Then, I called for volunteers. A hand went up almost immediately, & its owner came down to the overhead projector, not looking too nervous. She picked up the microphone, described her group’s scenario, & showed – & explained – their response. The next speakers followed just as quickly, and each speaker received a round of applause as they finished.

But the proof’s in the pudding – just what sort of plant had they designed? Well, they didn’t necessarily look like plants that my botanical colleagues could have put a name to, but nonetheless, the explanations each group gave for their particular design were sound, & science-based. They’d obviously taken on board not only the info on that fact sheet, but also the material we’d been looking at in lectures & that they’d found on line. And they’d had fun doing it. (I particularly liked the Nepalese Death Vine – the eerie noise of the wind passing through its herbivore-deterring spines apparently puts the locals off harvesting it, lol – and the Serengeti ‘cactus’ that traps water in basin-like leaves, but when there’s a fire the plant’s transpirative water loss is such that its tissues become flaccid and it wilts, spilling that water onto the ground where the dampness keeps the worst of the fire at bay.) Plus – so far, the feedback for this exercise on our Moodle page is all positive: students felt it definitely helped their learning about plants.

Thanks, Kevin – your design-a-plant lesson got an A+ from all of us today!

‘scientists anonymous’ write to me about ‘programming of life’

In some ways this is quite a way off from what I usually write for this particular blog (it’s from my Bioblog). I’ve republished it here because it’s something that I do want to get out to science educators – especially biology educators – as widely as I can.

I’ve written about the group who call themselves ‘Scientists Anonymous (NZ)’ before, in the context of determining the reliability of sources. At the time, I commented that I would have a little more confidence about the information this group was putting out there if the people involved were actually identified – as it is, they are simply asking us to accept an argument from (anonymous) authoriry. (I was rather surprised to actually receive a response to that post, albeit its authors remained anonymous.) Anyway, this popped up in my inbox the other day, and was subsequently sent to me by several colleagues in secondary schools:

TO: Faculty Head of Science / Head of Biology Department

Please find a link to the critically acclaimed resource (http://programmingoflife.com/watch-the-video) dealing with the nature of science across disciplines/strands.

Interesting to see an attempt to link it into the current NZ Science curriculum with its focus on teaching the nature of science.

 PROGRAMMING OF LIFE

• The reality of computer hardware and software in life
• The probabilities of a self-replicating cell and a properly folded protein
• Low probability and operational impossibility
• The need for choice contingency of functional information

Freely share this resource with the teaching staff in your faculty/department.

Yours sincerely

Scientists Anonymous (NZ)

So, I have been to the website. I intend to watch the video tonight (from a comfy chair), but the website itself raises enough concerns, so I’ll look at some of them briefly here. And I’ll also comment – if they really are ‘doing science’, then it’s not going to be enough to simply produce a list of ‘examples’ of the supposed work of a design entity (because that’s what all the computing imagery is intended to convey) & say, see, evolution’s wrong. That would be an example of a false dichotomy, & not scientific at all. They also need to provide an explanation of how their version of reality might come to be.

Its blurb describes the video as follows:

Programming of Life is a 45-minute documentary created to engage our scientific community in order to encourage forward thinking. It looks into scientific theories “scientifically”. It examines the heavy weight [sic] theory of origins, the chemical and biological theory of evolution, and asks the extremely difficult questions in order to reveal undirected natural process for what it is – a hindrance to true science.

The words ‘undirected natural process’ immediately suggest that this is a resource intended to promote a creationist world-view. I would also ask: if the documentary is created to ‘engage our scientific community’, then why did Scientists Anonymous send it to secondary school teachers in biology and not to universities & CRIs across the country? The blurb goes on:

This video and the book it was inspired by (Programming of Life) is about science and it is our hope that it will be evaluated based on scientific principals [sic] and not philosophical beliefs.

Unfortunate, then, that they wear their own philosophical beliefs so clearly: ‘undirected natural process’ as a ‘hindrance to true science’.

As well as linking to the trailer for the video, & the full video itself, the Programming for Life website also presents a bunch of ‘tasters’. One of these is the now rather hoary example of the bacterial flagellum (irreducible complextiy, anyone?) The website describes ‘the’** flagellum thusly:

The bacterial flagellum is a motor-propeller organelle, “a microscopic rotary engine that contains parts known from human technology such as a rotor, a stator, a propellor, a u-joint and an engine yet it functions at a level of complexity that dwarfs any motor that we could produce today. Some scientists view the bacterial flagellum as one of the best known examples of an irreducibly complex system. This is a single system composed of several well-matched, interacting parts manufactured from over 40 proteins that contribute to basic function, where the removal of any one of those parts causes the entire system to fail.

** As noted on my link for this example, there is no such thing as “the” bacterial flagellum as the sole means of bacterial locomotion: different prokaryotes get around in different ways. Nor is the flagellum a case of design; its evolutionary history has been quite well explained. The lack of quote closure (& of citation) is in the original.

 Mitochondria have their own executable DNA programs built in to accomplish their tasks.

Well, yes, & no. Several key mitochondrial genes are actually found in the cell’s nucleus – something that allows the cell to control some aspects of mitochondrial functioning (& incidentally prevents the mitochondria from leaving!). There’s a good review article here. That the number of nuclear-based mitochondrial genes differs between taxa is a good argument for evolution; for design – not so much.

Much like the firewall software on your computer the membrane contains protein gate keepers allowing only those components into the cell that belong and rejects all other components. The membrane is thinner than a spider’s web and must function precisely or the cell will die.

Well, d’oh – except when it doesn’t. Viruses, and poisons that interrupt cellular metabolism, get in just fine. They really are pushing the boundary with this computer metaphor.

The human eye is presented as an amazingly complex ‘machine’ – yet we have a good explanation for how that complexity evolved. And more telling (but omitted from this presentation): the eye’s structure isn’t perfect – it’s a good demonstration of how evolution works with what’s available,but hardly an argument for the wonders of directed design. The same can be said for the human skeleton, which is also in the taster selection, along with the nucleus, DNA, & ribosomes (which come with more, lots more, of the computer software imagery).

As I said earlier, if this video is not simply another example of the use of false dichotomy to ‘disprove’ a point of view with which its authors disagree, it had better provide more than metaphor. That is, I’ll be looking for a strong, evidence-based, cohesive, mechanism by which these various complex features sprang into being. Otherwise, we’re not really talking ‘nature of science’ at all.

_______________________________________________________________________________

I was going to stop there (for now) but then I noticed the ‘Investigate the facts’ heading. It links to a list of various papers & articles that supposedly support the ‘design’ hypothesis. Richard Dawkins’ name caught my eye – he’s there for writing that

Human DNA is like a computer program, but far, far more advanced than any software we’ve ever created.

I had a couple of thoughts; a) metaphor is a wonderful thing, & b) Dawkins is a biologist & science communicator, but not necessarily big on programming. (If I am inadvertently doing him a disservice, I apologise!). Someone else had the same thoughts.

a map for ‘basic biology bits’

Students in my first-year bio class have quite varied backgrounds in terms of their prior learning in biology. I’ve had a little survey running on our Moodle page in the lead-up to beginning to discuss plants: roughly 1/4 of them didn’t take year 12 (6th form) bio; 1/4 did, but didn’t study plants; and most of the rest both studied year 12 biology and learned about plants. (For readers outside of NZ, year 13 is the final year of high school.) This is going to make teaching about plants – which occupies not quite half of the paper, quite ‘interesting’. It also means, of course, that 25% of the class don’t have any formal leaning in biology as a separate subject at all: something that my colleagues & I need to keep in the back of our minds in our teaching.

And of course, even those who report having studied something in school may not actually remember it in any meaningful way, in the sense of having accurate conceptions about the topic. However,  the misconceptions that they may have in lieu can make expanding & correcting their understanding quite tricky. For this reason, a few years ago I began starting the new semester with a class called ‘Basic Biology Bits’ – pop quizzes & discussion around a few key ideas that many students appeared to be having trouble with. Feedback from the class was positive, so I’ve kept that in the curriculum.

However, having read & blogged about visual curricula, I realised that just dishing out a set of apparently unrelated concepts probably didn’t make a lot of sense to the students, even if they were gaining an enhanced understanding of the concepts in isolation. So now I have a little map to show them where we’re heading, & I thought I’d share that here (since my last post seems to have attracted so much interest, lol).

We started off with an idea that everyone agreed with – that living things are made of cells. Cells are very small, & I wanted them to think about why this might be:

This gave the opportunity to talk about just how ‘small’ is small & to introduce the units of measurement (micrometres) that they’ll be using with their microscope work in the lab. I find a lot of bio students tend to be quite maths-phobic & a little gentle intro to these units & also to the idea of converting between them will hopefully be useful when they come to work out the size of the things they’re seeing down the microscope. And the ‘why’ question meant that we could talk about diffusion & osmosis & why multicellular organisms need some sort of transport system.

We’d talked a bit about plants being autotrophs in a previous class, but I wanted to give a heads-up that they’d be learning more about photosynthesis in another paper. Turned out not all of them were familiar with writing or interpreting a chemical equation, so showing

CO2 + H2O + light energy –> C6H12O6 + O2

was quite useful as a means of signalling that they’d need to become familiar with the basics of chemical formulae. (Also, it turned out during the body of the lecture that I’d got a mistake on the relevant slide. Someone was brave enough to point this out, & I thanked him & took the time to say that this was good; students shouldn’t be afraid of asking if they think someone’s made a mistake, just as it’s important to ask if they don’t understand something.)

A few years back I was rather taken aback to discover a particularly common misconception among our first-year bio students: the idea that plants photosynthesise, but don’t respire. Ever since I’ve taken the time to point out that all living cells respire, albeit not necessarily aerobically. I use a couple of pop quizzes on the processes that cells might need energy to carry out. And we also talk about ATP as a carrier of energy – and why cells might need such carriers.

(Don’t know how I managed to include that line just above!) It’s interesting to think about respiration & photosynthesis in terms of the carbon cycle, something that we’ll be considering in more depth towards the end of the semester.

 And finally, reminding them of the role of DNA in controlling all these goings-on. (That 25% of the class who didn’t study biology at the senior high-school level are going to need a lot of help in this area!) When we looked briefly at mitochondria & chloroplasts I noted that both organelles have their own loops of DNA – & asked why some mitochondrial genes are located in the nucleus & not in the mitochondria at all. A very interesting discussion ensued.

Teaching like this is probably more work, in some ways, than a traditional lecture. It certainly can demand more of the lecturer. But I firmly believe it provides a much better learning experience for the students! The thing is, you just need to signal what you’re going to do from the start – and explain why. “I’m going to be teaching in this way because science education research clearly shows that it significantly enhances learning outcomes for students.” That way, we’re all in the same boat & paddling in the same direction :-)

what is the caminalcule lab supposed to teach?

It’s quite interesting (& post-provoking) to read the search terms for this blog every now & then. Today’s examination gave me the title of this post :-)

I was first introduced to the Caminalcules way back in the dim dark past when I was a brand new undergraduate student. They were the basis of a lab exercise on evolution & evolutionary relationships, & were invented by the taxonomist Joseph Camin to aid learning about taxonomy & classification. Here’s what they look like (these are just the ‘living’ species):

The idea was to sort them – both ‘living’ and ‘fossil’ species – into groups on the basis of various similarities, & then to work out a possible family tree (a phylogeny) that reflected their possible evolutionary history. Camin used made-up ‘animals’ rather than actual organisms because he wanted to avoid students’ preconceptions about relationships affecting the development of their phylogenetic trees.

I must have found this rather fun because, when I was in the position of redeveloping a paper on the evolution & diversity of life, I remembered the Caminalcules & decided to use them as the basis of a lab class myself. As you do, I did a little googling & found not only the images of fond memory, but also a lab exercise developed by Rob Gendron, of Indiana University of Pennsylvania. Rather than reinvent the wheel, I e-mailed Rob & he very kindly allowed me to use his lab exercises in our BIOL201 paper. (And I’m extremely grateful that he was so generous with his resource – if you read this, Rob, thank you again!)

I must admit, I did wonder what today’s computer-savvy generation of students would think of a paper-&-scissors exercise, but apart from one or two who felt it a bit kindergarten-ish, everyone seemed to enjoy identifying the features that would (& wouldn’t) be useful in working out relationships & in building up what turns out to be quite a complex family tree. Along the way they learn about synapomorphies (features shared by a particular group that derive from a common ancestor for that group); how to recognise convergent evolution; and the taxonomic significance of vestigial characteristics (among other concepts). They’re also challenged to think about how environmental conditions might drive the diversity seen in some lineages of Caminalcules, and similarly, why other lineages appear to be in evolutionary stasis.

You can see that there’s a lot of concept development, & good hard thinking, going on in this lab. Because it’s such a good introduction to thinking about evolutionary history, I used it as the first lab in our 12-week semester, to give the students the framework into which to fit the concepts & ideas they’d be gaining as we worked through the rest of the paper. Camin’s original concept has turned out to be one useful, & long-lived, idea :-)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When I went looking for the image I’ve used here, I was enchanted to also find the “Snouters“, another family of imaginary creatures. (I actually have the book about them, thanks to one of my brothers.) So nice to be reminded that science doesn’t always match the popular image, but is also about creativity, imagination, & downright fun!

assessment for learning

A month or so back, my friend  Grant asked if I would follow up on my promise to write something on assessment. It would be great to get a discussion going around how & why we assess students, so after a bit of thought I decided to kick things off with the following post, derived from my own teaching portfolio document. (I rather feel that I need to be careful that too many of my posts don’t become Oracian in length! Not that there’s anything wrong with Orac’s posts!) It was originally posted over at Sciblogs.

For all teachers, the $64-question is whether students are learning (and, whether they’re learning what we would wish them to learn!). Assessment is the usual tool for finding this out, although it may have unintended consequences when the nature of the assessment task shapes what and how the students learn. It took me a while to realise this – and it may be that many tertiary teachers still don’t realise this, perhaps because they are focused on teaching the content in a particular discipline rather than on the best methods for doing that.

Students tend to focus on tests and final examinations, which are forms of ‘summative’ assessment; they give the assessor an indication of where the students are at, at the end-point of a program or part thereof. The downside of this is the situation where students use techniques such as rote learning to prepare for these assessments, without necessarily taking the information on board for the long term. This is exacerbated when lecturers ask questions that simply test recall rather than in-depth understanding. Far better to ask a mix of questions, with some that can be answered through recall of facts sitting alongside those that require comprehension, understanding, and critical thinking. Students who tend to use surface-learning approaches can attempt the recall-type questions. but the ‘deep’ questions encourage and reward deep-learning strategies. This mix of questions means that it’s possible to use summative assessment techniques to encourage a ‘desired’ style of learning and thinking, particularly if you let students know in advance the type of question that they can expect.

Now, if summative assessment gives you (& the students) a snapshot of where they’re at by the end of a paper, how can you use assessment to improve their learning along the way? By using a range of formative assessment strategies to build student capability, understanding, and confidence.

Formative assessment takes many forms. The most obvious is probably written feedback on reports and essays – time-consuming to deliver, but far more useful to students than simply giving them a grade. UK educator Phil Race suggests giving feedback almost immediately andwithout a grade – because often the student will look at the grade and then pretty much ignore your carefully-crafted comments. Bridget & I try to do this with the essays our students write in first-year, by giving everyone some generic feedback on the issues that we know from experience will be very common. Then we don’t have to address all that individually & can focus on the specific areas with each essay that are good or in need of improvement. Having a good marking rubric – provided to the students along with the essay topics – is a big help with this. In fact, having that rubric also means (says Phil) that you can also get students to evaluate their own work. This may sound a bit counterintuitive but it’s a good way of encouraging them to reflect on the quality of what they’ve done.

Reviewing initial drafts can also help develop a range of process skills, although with a large class I doubt that teaching staff could actually look at them all! On the other hand, you can encourage students to give this sort of feedback to each other during tutorials; it’s a good learning experience for both the reporter & the reportee… Whatever way it’s done, while university assessment practices remain centred on written tests and exams, it’s really important to help students develop these skills. For example, extended essay-type answers are expected to show the writer’s understanding of key concepts and the ability to think critically about information from a range of sources. Yet science students fresh from the NCEA may not have these skills, because even ‘discuss’ questions require only relatively brief answers. So finding ways to provide meaningful formative feedback on essay assignments gives students valuable learning opportunities & also makes it more likely that they’ll develop the deep learning skills needed for real mastery of a subject.

I’ve written previously about other, in-class techniques that can provide students with immediate formative assessment on where they’re at with their understanding of a subject (here, and here, for example). Actually, the lecturer gets formative feedback too – if class responses to an item show a general lack of understanding on an issue, then that should be a pretty clear signal that I need to try a different approach :-) Over the years that I’ve been teaching I’ve increasingly incorporated some of these techniques, & one that both I & the students (judging from their comments eg “I really like the little quizzes in lectures, the conversations, and the freedom to ask questions”) find useful is in-lecture pop quizzes.

The way I use them, each quiz consists of one or a few questions that either examine students’ prior knowledge of a concept we’re going to discuss, or test their memory & understanding of concepts just covered. Students discuss their responses with each other & then I display the answers on screen & explain why I think a particular response is the correct one. (Quite often this will lead to further discussion.) There’s no pressure, no marks, but the class gets immediate feedback on where they’re at. Plus, the use of techniques like this can lead to greater student engagement and promote more active learning.

As well as encouraging students to think more deeply and critically, teaching methods like this also help them to make connections between concepts and ideas, and with their existing knowledge framework. Sometimes this can be a bit uncomfortable, when you find that existing & new information simply don’t fit together & you have to do a bit of hard analysis of your viewpoint (the ‘troublesome knowledge’ that Michael Edmonds wrote about on Sciblogs NZ). And the evidence is there that learning to link concepts in this way does have a positive outcome for our students: while for ‘recall’ questions there was no difference between students who’d learned concept mapping & those who had not, for big-picture and interpretive questions there was a statistically significant improvement in pass rates for the concept-mapping group (Buntting et al., 2005).

Of course, assessment is only part of a bigger picture. Whatever the assessment techniques you use, they have to fit within papers with a clear outline of their structure & content, so that students are aware from the start of the material they will be covering. (If you’ve read an earlier post on visualising a curriculum, you’ll know that this does come with a caveat.) They need to know how – and why – the course will be assessed. It’s also a good idea to spell out your expectations of the students, and what they can, in turn, expect from their lecturers. All these things work together to encourage students to develop an independent, deep-learning approach to their studies – & set them up for learning for life.

Now I need to get on & write something about assessment & learning objectives…

C.Buntting, R.Coll & A.Campbell (2005) Using concept mapping to enhance conceptual understanding of diverse students in an introductory-level university biology course. Paper presented at the 36th annual conference of the Australasian Science Education Research Association. 

motivating tomorrow’s biologists

That’s the title of Susan Musante’s paper in the latest issue of Bioscience (& many thanks to David Winter for sending it on). It’s a summary of some key points made by speakers at an NAS convocation called “Thinking evolutionarily: evolution education across the life sciences.”

Now, I find science fascinating, exciting, & endlessly interesting, & I’m sure my colleagues feel the same. The thing is, how to pass all that on to our students? As I’ve said before, simply providing them with quantities of facts is not going to do it. At the convocation, several speakers stressed that

[simply] regurgitating the biological knowledge generated by the scientific community or conducting “cookbook” laboratory experiments does not result in genuine understanding or excitement on the part of students… Instead, the nature and process of science, the unifying concepts and connections to the real world, and the problems encountered and discoveries made by scientists are what make biology come alive.

Biologists, of course, recognise the complexity of their subject all too well. However, I suspect that our desire to ‘get the facts across’ obscures that complexity and at the same time works against – rather than for – student engagement. So, how can biology educators motivate their students as they come to understand our fascinating subject?

One part of the equation is how it’s taught, something I’ve discussed before (here, for example). While those lecture-room techniques can make a real difference to student understanding and mastery, there are other learning environments to consider. Beginning to move away from ‘cookbook’ labs is part of it. Yes, there are practical skills that students need to learn, but why not look for ways to deliver those skills in contexts that are more meaningful and relevant to the students? For example, in the B semester our first-years practice a lot of those skills in the context of solving a ‘whodunnit’, finding out who disposed of the paper coordinator (me!). (OK, we chose that one because of the generally high interest in shows like CSI; other contexts would work as well. Anything to move away from following a recipe to get a result that most in the class probably realise is a ‘given’.)

Another tool – and an important one, if we’re hoping to give our students a feel for what scientists actually do, is to give them a chance to work with primary data – something that is in ready supply in universities :-)  There are some great resources for educators in the BioQUEST database, such as the Beagle Investigations Return with Darwinian Data, or BIRDD, to use in giving students that experience. Musante also quotes David Mindell (of the California Academy of Sciences) on the benefits of field trips:

We have a real disconnect between students and the natural environment

he says, and we should recognise that

allowing students to explore the outdoors through research projects is a proven way to encourage them to inquire deeply about the world in which they live.

This is something that the University of Sydney’s Pauline Ross uses to great effect with her undergraduate students.

We can use well-designed assessment tools to provide some extrinsic motivation to students, but giving the opportunity to gain personally-relevant experiences through such activities may well be more effective in the long run. Letting students gain those relevant experiences seems to be particularly important

for students that are under-represented in the sciences and students that initially have low expectations for success,

according to another speaker at the convocation, Paul Beardsley. This is something that deserves much closer attention here in NZ, especially when the Tertiary Education Commission’s funding priorities are taken into consideration.

Musante’s thoughtful summary provides links to a range of databases that teachers should find useful, and ends with a reminder that educators need to be students as well – not only adding to their own subject knowledge, but continuing to learn

about what motivates students and works to engage them, [so that] their students will be able to take ownership of their own learning. And that is essential if we are to increase the biological literacy of today’s students, who are tomorrow’s politicians, school board members, precollege teachers, and voters.

S.Musante (2012) Motivating tomorrows biologists. Bioscience 62(1): 16 doi: 10.1525/bio.2012.62.1.5

the status & quality of year 11 & 12 science in australian schools

My reading assignment today was a report just out from the Australian Academy of Science(the AAS) on science in Australian secondary schools (Goodrum, Druhan & Abbs, 2011). Not what you might expect on a reading list in the week before Christmas, but I was up to speak (briefly) about it on Radio NZ & needed to have an idea what the report contained.

It’s a really thorough study of the state of senior school science across the Tasman, based on an extensive literature review, a survey of students (both those taking science, & those who aren’t) in NSW, South Australia & the Australian Capital Territory, a phone survey of senior science teachers in the same states, and a series of focus groups involving not only teachers and students but also scientists & members of the wider community. This allowed Goodrum & his colleagues to describe the ideal state of senior school science education in Australia (my marginal note at this point says ‘Wonderful! but does it/can it happen?) in terms of students & the curriculum, teaching as a profession, the resourcing of science teaching & learning, and the value of science education. They describe the last item thusly:

Science and science education are valued by the community, have high priority in the school curriculum and science teaching is perceived as exciting and valuable, contributing significantly to the development of persons and to the economic and social well-being of the nation.

And then… they identified the actual state of affairs, “by focusing on different dimensions of the school experience: the students, the curriculum, the pedagogy, the teachers and finally the resources.”

I must say that I think we are well ahead of the Australian state of play in terms of the curriculum document as discussed in the AAS report: Yes, the NZ curriculum is probably still too content-heavy, but at least the clear understanding and expectation is that senior school science should do much more than simply prepare a relatively small cohort of students for university. (This is something that I believe the universities need to be much more aware of, as otherwise we will continue to have a disjunction between lecturer expectations and the actual prior learning experiences of our new first-year students.) Also, the NZ Science curriculum explicitly requires that students be given the opportunity to learn about the nature of science; it’s not all about content knowledge. However, the AAS survey found that both students and teachers in the Australian school system believed that

Year 11 and 12 science is constructed to prepare students for university study. This university preparation perspective has resulted in an overcrowded content-laden curriculum. WIth the amount of content to be covered there is little room for flexibility from either the teacher or student.

Goodrum & his colleagues also found that most senior science teaching** in the schools they surveyed is done using the transmission model (teacher talks or writes on the board – or uses powerpoint – & students simply write it all down); that teacher demonstrations are common; and that practical sessions tend to be of the ‘cook-book’ variety where the outcomes are already known and the students are simply following a pre-determined method. Where there isopportunity for more inquiry-based learning in labs, teachers reported that these really sucked through the time & that this in turn led schools using open-ended student projects to advise students not to take all three sciences as the demands on their time would be too great.

So what did they find when they looked at levels of participation in senior science: the proportion of students in each year’s cohort who were enrolled in science subjects in their final 2 years of secondary school? The news was not good, and it’s news that’s obviously generating a lot of concern: looking at the proportion of students enrolled in each discipline in each year, they found that

[s]ince 1991, the percentage of students enrolled in Biology, Chemistry and Physics has been gradually falling. For Biology the fall has been from 35.9% in 1991 to 24.7% 2007, for Chemistry 23.3% in 1991 to 18.0% in 2007, and for Physics 20.9% in 1991 to 14.6% in 2007. While the fall has slowed there is no indication that it has stopped.

(The proportion taking Psychology, on the other hand, has almost doubled – from 4.9% in 1991 to 9.2% in 2006. Geology – this in a country where mineral resources are so significant to the economy – has remained at a fairly constant 1% throughout the study period.)

And looking at total science enrolments in Year 12:

there has been a dramatic fall in the percentage of students studying science in Year 12 from a height of 94.1% in 1992 to a low of 51.4% in 2010

with a particularly large drop-off in the period 2001-2002. The researchers weren’t able to identify any reason for this in terms of policy changes. Part of the decline may be linked to how students perceive science in schools – something that probably needs to be addressed in junior schools, because

Some non-science students report that if science was more ‘interesting and relevant to their lives’ then they would consider enrolling in it… Many, however, think so poorly of their experience and achievements in junior secondary science** that they won’t consider senior science under any circumstances.

This is a real pity, as the community members surveyed clearly felt that all students need to study science throughout their schooling – it shouldn’t be just for those who need it for their careers. They felt that science in schools

should be relevant… and demonstrate how science understanding and process impacts daily life.

Which is great – but I did wonder if those sentiments are shared by the wider school community as a whole (parents, teachers, students, the works). Schools do seem to be under pressure to broaden their curriculum, which places time constraints on teachers in the various subjects, & at least some of that pressure comes from the communities in which the schools are situated.

So how do the Australian data stack up compared to senior science education in New Zealand? I gathered from my radio host that the PM’s Chief Science Advisor, Sir Peter Gluckman, will be soon releasing a report on just this issue. Watch this space.

** The researchers make the point that this is different from the teaching methods used in junior (our years 9-11) science classes, and suggest that “[p]erhaps this more enlightened approach in the junior years should influence how science is taught in Years 11 & 12.” (Some students obviously gained a different impression…)

D.Goodrum, A.Druhan & J.Abbs (2011) The Status and Quality of Year 11 and 12 Science in Australian Schools. A report prepared for the Office of the Chief Scientist.