Zombie stats and hair-trigger outrage: reflections of a Twitter addict

It seems somehow odd to come over all reflective about Twitter, that most impulsive of online communication channels. But over the year or so that I’ve been using it as a kind of super-effective personalised newsfeed, several cautionary tales have played out in my Twitter feed, which I have here distilled into two key lessons. First: distrust numbers, even – especially – those whose implications sit well with your worldview. And second, reign in your outrage: issues are almost certainly more complicated than 140 characters allow. Twitter, by its very nature, gives you soundbites. If you’re lucky, you’ll get a link to something more substantial, but it is so very easy to retweet something that appeals to your sense of how the world works without scrutinising the numbers. My favourite example (not least because it got me onto BBC R4’s More or Less!) is the ludicrous ‘100 Cod in the North Sea’ story that I blogged about last year. Now it takes just a moment’s thought, if that, to realise that this number is very very wrong (by a factor of at least several hundreds of thousands, in fact). But it played so nicely into the ‘overfishing is devastating our seas’ narrative that many people declined to give it that moment, and unthinkingly retweeted.

This is just one example, but my Twitter feed is full of them. I’m interested in the natural environment, and the impacts that we are having upon it, so I follow a range of environmental groups who tend, for instance, to jump immediately on numbers making renewable energy look especially attractive. Now climate change terrifies me, and I am fully behind the idea that we need to decarbonise the economy as a matter of some urgency. But I also agree wholeheartedly with David McKay who, discussing the favourable carbon footprint on nuclear power in his (essential, free) Without the Hot Air, states “I’m not trying to be pro-nuclear. I’m just pro-arithmetic”. Fortunately, the vigilance of people such as Robert Wilson (@CarbonCounter_) provides a corrective to some of these numbers (see for example his dissection of an awfully inaccurate Guardian report on costs to consumers of gas vs. renewables). But such arguments rarely translate so well to Twitter soundbites and so the zombie stats – numbers that we know are wrong, but which are appealing – refuse to die.

What’s the harm in all this? In my post on the cod story I mentioned the fragile trust that now exists between the fishing, scientific and conservation communities which has led to promising progress in the recovery of North Sea cod stocks but which can easily be shattered by the promulgation of laughable statistics. More generally, dubious numbers muddy whatever water they fall into. In his excellent critique of mainstream economics The Skeptical Economist, which I reviewed previously, Jonathan Aldred warns that “dubious numbers are infectious: adding a dubious number to a reliable one yields an equally dubious number”. Which leads me to propose Mola mola’s second law¹:

An argument advances with the rigour of its most dubious number

So it doesn’t matter how watertight the ethical case for regulating cod fisheries, or for moving away from fossil fuels; if you use farcical numbers to advance this case, the argument will fail to progress.

Another consequence of these kinds of zombie stats is the hair-trigger outrage for which Twitter is (in)famous. This applies just as much to the niche worlds of the practice and administration of science as it does to Westminster or celebrity gossip. In particular, it is rare for a day to pass without some call appearing in my timeline to sign a superficially worthy-looking petition. I am extremely wary of doing so, for a couple of reasons.

For instance, a while back I signed something against some kind of reforms (I didn’t read the details) in a European marine institute which I have visited a few times and where I have friends and colleagues. Surely I should support them in their hour of need? Hmmm. Well. Next time I went, my friend – an extremely conscientious and committed member of the institute – said words to the effect of ‘Please, nobody sign that petition. These reforms are exactly what we need and the people fighting against them do nothing here.’ Duly chastised, I resolved to be more discerning in future.

Then there was the curious incident of Nerc’s planned merger of the British Antarctic Survey with the National Oceanography Centre. Now it is my view that Nerc handled this pretty poorly, but although there were some pretty convincing arguments – both scientific and geopolitical – against this merger, there were good arguments for it too, and chatting to people I know at both NOC and BAS (as well as reading things like this excellent coverage from Mark Brandon) just confirmed to me that this was very far from the black and white issue painted by many environmental journalists and pressure groups who backed a petition against it. And the joy which met the announcement that the merger (which is what was proposed, although it was typically presented as the 'dismantling' or ‘abolition’ of BAS) made no mention of the budgetary constraints at Nerc which had prompted the proposal, which still exist, and which will now require that savings be made in some other area of environmental science.

To reiterate: I don’t know whether the correct decision was made. But that’s precisely the point. I know the issues and institutions involved pretty well, yet didn’t feel sufficiently well-informed to decide one way or another. In such a case, it would be hugely irresponsible of me to sign any petition. Yet many thousands of people did. Call me an old cynic, but I doubt all that many of them had read widely on the rationale for the merger. Sadly, it is now far easier to create a petition – let alone sign one – than it is to inform yourself about an issue. Of course, the UK government has made a rod for its own back here with e-petitions initiative and its commitment to debate in parliament any issue that gains 100,000 signatures. But it is our responsibility as thoughtful citizens to take the issue of signing a petition seriously. Which usually means basing our opinions on more than 140 characters of research.

Bearing these caveats in mind, and keeping critical faculties engaged at (almost) all times, Twitter remains for me an essential source of information, conversation and debate, and an invaluable means to publicise work and opportunities, and I encourage non-tweeters to have a go - good guides for sciencey-minded beginners here, here, here and here.

¹First law here

How to Ace an Essay

Preamble I’ve seen a few posts recently on ‘how to write’ for scientists, from the technical (this on how to write a paper) to the more general (this on how to write clearly). So here’s my contribution: how to write an essay. Now I’m all to well aware that, as Brian McGill, author of the ‘how to write clearly’ piece states, this kind of enterprise inevitably teeters on the edge of hubris (both pieces referred to above fall the on the right side, I hasten to add!), so let me make clear my motivation. This is essentially an extended piece of feedback to my undergraduate tutees, following the first essays that they submitted to me this month. The aim of this exercise was to make sure they all achieve a mark for a tutorial essay that is commensurate with their abilities by the end the academic year, and that they also do as well as they can in exams. Much of what appears below is obvious or well-known; some of it is perhaps rather specific to our assessment procedures. But it directly addresses issues that our students have found challenging on occasions, so on the off chance that it is more widely useful, I thought I’d post it in its entirity here…

Before you start

Read any instructions regarding format, filenames etc. If working in Word, use File>Save as to give your essay an informative filename (including your name) rather than just accepting the default. Don’t call it ‘essay.docx’. Please!

Especially in exams - make sure that everything in your essay is geared towards answering the question.

Read around the subject. Use reasonably general search terms in google scholar or web of knowledge, and search back through the reference sections of papers you read, and forward through papers that have cited them, for other relevant work. The primary literature (peer-reviewed papers) should be the first and major place you look for information. Looking to e.g. Wikipedia first then following up references from there is not good practice.

Make sure that any notes you take clearly state their source; in addition, if you copy and paste directly from a source, it’s sensible to paste into quotation marks so you’ll remember that you can’t copy directly from your notes into your final essay. So for instance, you might end up in your notes with something like:

Webb et al. PLOS1 2010 show that deep pelagic ocean is underexplored compared to coastal seas: “The deep pelagic ocean is the largest habitat by volume on Earth, yet it remains biodiversity's big wet secret, as it is hugely under-represented in global databases of marine biological records.”

You’ll know then that the first statement can be used in your essay (referencing the paper, of course – see below), but the exact phrasing in the quotation marks should be avoided (unless you want to include it as a direct quote – which can be done from time to time, but only really if the quote is particularly striking).

Because you’ll probably forget to do that from time to time, never copy and paste from your notes into your final essay. This is a good way to plagiarise by accident – you read something in your notes, think it sounds great, forget that you copied it wholesale from somewhere else. (Note: plagiarism-detection software is dumb, but thorough; careless copy-pastes will get picked up.)

For better or worse (OK, for worse) we use MS Word for our essays. Word is a good word processor, but it’s pretty awful at many other things. So keep your formatting simple (single column, don’t try to wrap text prettily around figures, etc.) – it is far  more important that your essay is easy to read (single column, decent sized font) and to comment on (consider 1.5 or double line spacing), than that it bears any kind of physical resemblance to a published paper or magazine article.

Next, and most importantly: write a plan. This can take several forms. A nice idea is to try to write a 25 word summary of what you plan to cover in the essay – this forces you to focus on what you think is important to answer the question (and is borrowed from a nice piece on how to write a scientific paper from Conservation Bytes).

You should also write a list of subheadings. Make these quite specific: ‘Introduction’, ‘Body’, ‘Conclusion’ are useless; rather, list the topics or points of view that you think it is important to cover in your essay. You may have a dozen or more for a standard 1200-2000 word essay. This approach has a couple of advantages. First, you can shuffle the subheadings around until the order makes sense to you – each heading should logically lead on from the previous one – and by keeping the plan to hand when you write your essay, you can avoid drifting off on tangents. In addition, by breaking down the essay in this way you are left with a series of short and quite specific paragraphs to write, rather than an entire essay (which can seem daunting). There’s nothing to stop you retaining some subheadings in your final essay, although probably fewer than in your plan.

Finally, as in everything you write, you need to think carefully about your audience. This is a general tip for clear writing in any context (see this post by Brian McGill), but takes on a rather specific meaning when you’re writing an assessed essay: think about whether the person marking it will be marking 150 others (common for exam essays) or 5 others (e.g. in a tutorial situation). In the former case, content and structure become more important than style: you really want to hammer home at the beginning exactly how you plan to answer the question, and at the end to reiterate exactly how you have just answered it. A tutorial situation, where both you and the marker have a little more time, gives you more opportunity to indulge your literary pretensions (although style will not win you marks lost on poor content).

Now you’ve worked out what you want to write, you just need to…

Write the damn thing

Obviously, you should start with an Introduction. This should cover three key points: What, Why, and How.

What is a brief introduction to the topic, and Why says why this is important, what is controversial and/or unknown (and hence why an essay is required). Finally, How sets out exactly how you intend to address the topic in your essay. Don’t be afraid of finishing your introduction with a sentence along the lines of “In this essay, I will show that…”

A note on style: in my view, personal pronouns and opinions are not only fine, but pretty much obligatory for a good essay (although some colleagues will disagree). So yes, you can say “I will show…”, “I think…”, and so on. Far better than “…it will be argued that…” and other passive voice horrors. But keep the tone formal: “do not” rather than “don’t”.

The structure of the Body of your essay will be drawn directly from your essay plan, and you can retain some subheadings if you like. Use diagrams, graphs or other images if appropriate – but only if appropriate. A well-designed or well-chosen figure can really enhance an essay, but a gratuitous one is unlikely to garner you any extra marks.

Finally, you want to draw some Conclusions. Broadly speaking, what you want to do here is to re-state the What and Why from the Introduction, and to sum up How you’ve addressed the issue. If the essay title is a question (and especially in an exam), hammer home here how you have answered it. For example, if the essay asks you to weigh up the evidence between two theories and determine which is more likely to be true, make sure you get into your conclusion something like “In sum, the weight of evidence supports x and I therefore conclude that x is more likely than y…” This is no place for subtlety!

Referencing

OK, this is the tough one. I have been writing scientific prose for so long that referencing is second nature to me, and I can’t for the life of me work out why it causes so many problems. But following discussion in the tutorial here are a few guidelines.

First: reference stuff you’ve read. Don’t reference stuff you haven’t. I know from personal experience that work gets cited wrongly (e.g. “Webb (2012) states…” when in fact I had stated the opposite!), so don’t rely on somebody else’s interpretation of what Webb (2012) actually said. If you really can’t track down the original source, then you can put e.g. “Darwin (1859, cited in Webb 2012)”, but try not to make a habit of this.

Second: every factual statement you make (that is not something that you have derived for yourself) needs to be backed up with a reference to the literature. If that means that in one paragraph, you reference the same work 10 times, then so be it (although see the point about synthesis below). Sometimes this can be tough – if, for example, you want to quote a very well-known fact, such as the diameter of the Earth, it’s may to be difficult to find a paper that gives this information. Text books can be very useful here in providing an authoritative source of basic information (whilst recognising that every practising scientist will simply have looked at Wikipedia, you shouldn’t!)

In terms of how you actually cite stuff, your best guide is the papers you read, but here are some general pointers: a single author study is cited as Webb (2012), a two author study as Webb & Freckleton (2007), and a study with more than two authors as Webb et al. (2010) (forgive my lack of imagination, it’s late…) Note that ‘et al.’ is short for ‘et alia’, hence the ‘.’ after ‘al’. Notice too that author surname only is given in the text – no initials, no first name.

It’s also useful to think about where the brackets come. So, you can write “As has previously been shown (Webb 2012) this is nonsense…” or “As Webb (2012) showed, this is nonsense…” – in reading phrases with a reference, you mentally skip everything in brackets.

Another point of style: it’s punchier to refer to authors by name, so “Webb et al. (2010) demonstrated that…” rather than “researchers have shown… (Webb et al. 2010)” or worse, “scientists believe… (Webb et al. 2010)”. In doing this, the grammar of the sentence should follow the number of authors to whom you’re referring – so “Webb (2012) states that… he also showed…” but “Webb et al. (2010) state that… they also showed…”

Now: how can you pick up extra points? One of the things we look for is synthesis. One way to demonstrate this is to summarise the findings of several studies in a single sentence, so “…multiple lines of evidence suggest that this effect is weak at best (Smith 2000, Jones et al. 2005, Smith & Jones 2007, Webb 2012)”. Once you get into this habit, then the problem noted above – having to cite a single reference repeatedly over the course of a paragraph – ought to diminish, as each of your paragraphs will be a synthesis of insights you’ve drawn from a number of papers.

Another thing we’re very keen on is critical analysis, which again you can demonstrate through citation, e.g. “Smith (2000) claimed that… However, I agree with Webb et al. (2010) that this was highly unlikely because…” You have shown that there are two points of view, and that, after due consideration and critical analysis, you have come to your own conclusion (the correct one, in this case, naturally).

Finally, everything you reference should appear in a single reference list at the end of the essay (ordered alphabetically by the first author’s surname); nothing that you have not referenced in your essay should be in this list. (Don’t look for a list at the end of this piece, I’m just making stuff up…) Formatting this list is easy: just pick a journal and copy their style (although best to choose a journal that uses the Name (Year) format for referencing, rather than numbered references).

There are numerous minor permutations of formatting, what’s important is that you’re consistent, and that you get the key information in. So, let’s dissect one of my papers:

Webb, T.J. (2012) Marine and terrestrial ecology: unifying concepts, revealing differences. Trends in Ecology & Evolution 27: 535-541

Here we have the author’s name and initials – if there are multiple authors, include all names here. We have the year. Then comes the title of the paper, the name of the journal, the volume of the journal, and the page numbers. That’s all that is necessary, and all of this information should be easily accessible, usually from the front page of any paper you read. For some online articles, you may find only what’s called a ‘doi’ (digital object identifier), which can replace the volume and page no. information (but not the rest). You can cite books in a similar way (authors, year, title, publisher), and chapters from edited books too (authors, year, title, book editors and book title, publisher) – again, have a look at the reference sections of the papers you read for tips. Bold, italics, etc. are optional – again, consistency is the key. Likewise your decision regarding whether or not to abbreviate journal titles (e.g. I could have used TREE for the reference above, but would need to abbreviate all others in my list then too).

And that’s it. Begin by following this advice, and hopefully as your confidence (and marks) increase you will start to break some of the rules and forge your own style. If you want an independent view, you can download a guide written by University of Exeter students from here.

Oh – one final thing. Spell check. And proof read. Read each other’s essays if that’s helpful. Silly, avoidable mistakes will tip the balance downwards if you’re on the borderline between grades.