Science for Non-Scientists: How to read a journal article

Scientific journal writing has a problem:

  1. It’s the main way scientists communicate their findings to the world, in some ways making it the carrier of humanity’s entire accumulated knowledge and understanding of the universe.
  2. It’s terrible.

It’s terrible for two reasons: accessibility and approachability. This first post in this series discussed accessibility: how to find papers that will answer a particular question, or help you explore a particular subject.

This post discusses approachability: how to read a standard scientific journal article.


Scientific papers are written for scientists in whatever field the journal they’re published in caters to. Fortunately, most journal articles are also written in such a way that you can figure out what they’re saying even if you’re a layperson.

(Except for maybe math or organic chemistry synthesis. But if you’re reading about math or organic chemistry as a layperson, you’re in God’s hands now and I can’t help you.)

Okay, so you’ve got your 22-page stack of paper on moose feeding habits, or the effects of bacteriophage on ocean acidification, or gravitational waves, or whatever. What now? There are two cardinal rules of journal articles:

  1. You usually don’t have to read all of it.
  2. Don’t read it page by page.

Journal articles are conveniently broken into sections. (They often use the names given, or close synonyms.) I almost always read them in the following order:

20160705_110250

1. Abstract

The abstract is the TL;DR of the article, the summary of what the studies found. Conveniently, it’s first. The abstract is very useful for determining if you actually want to read the rest of the article or not. Abstracts often have very dense, technical language, so if you don’t understand what’s going on in the abstract, don’t sweat it.

2. Introduction

As a layperson, the introduction is your best friend. It’s designed to bring the reader from only a loose understanding of the field, to “zoom in” to the actual study. It’s supposed to build the context you need to understand the experiment itself. It gives a background to the field, what we already know about the topic at hand, historical context, why the researchers did what they did, and why it’s important. It’ll define terms and acronyms that will be crucial to the rest of the paper.

It may not actually be easy language. At this point, if you encounter a term or concept that’s unfamiliar (and that the researchers don’t describe in the introduction), start looking it up. Just type it into Wikipedia or Google, and if what you get seems to be relevant, that’s probably it.

3. Conclusions

In a novel, skipping to the end to see how the suspense plays out is considered “bad form” and “not the point.” When reading papers, it’s a sanity-saving measure. In this part of the paper, the researchers write about what conclusions they’re drawing from their studies,and its implications. This is also done in fairly broad strokes that put it in context of the rest of scientific understanding.

4. Figures

Next, go to the figures that are strewn around the results section, just before the conclusions. (Some papers don’t have figures – in that case, just read the results.) Figures will give you a good sense of the actual results of the experiments. Also read the captions – captions on figures are designed to be somewhat stand-alone, as in that you don’t have to read everything else in the paper to tell what’s going on in the figures.

Depending on your paper, you might also get actual pictures of the subject that illustrate some result. Definitely look at these. Figure out what you’re looking at and what the pictures are supposed to be telling you. Google anything you don’t understand, including how the images were obtained if it’s relevant.

In trying to interpret figures, look at the labels and axes – what’s being compared, and what they’re being measured by. Lots of graphs include measurements taken over time, but not all. Some figures include error measurements – each data point on a graph might have been the average of several different data points in individual experiments, and error measures how different those data points were from each other. A large percent error (or error bar, or number of standard deviations, etc) means the original data points were far apart from each other, small error means that they were all close to the average value. If you see a type of graph that you’re not sure how to read, Google it.

5. Results

The section that contains figures also contains written information about the researchers actually observed in the experiments they ran. They also usually include statistics, IE, how statistically significant a given result is in the context of the study. The results are what the conclusions were interpreting. They may also describe results or observations that didn’t show up in figures.

Maybe read:

Methods

Methods are the machinery of the paper – the nuts-and-bolts, nitty-gritty of how the experiments were done, what was combine, where the samples came from, how it was quantified. It’s critical to science because it’s the instructions for how other researchers can check what you did and see if they can replicate the results – but I’d also rather read Youtube comments on political debates than read methods all day. I’ll read the methods section under the following circumstances:

  • I’m curious about how the study was done. (You do sometimes get good stuff, like in this study where they anesthetized snakes and slid them down ramps, then compared them to snakes who slid down ramps while wearing little snake socks to compare scale friction.)
  • I think the methodology might have been flawed.
  • I’m trying to do a similar experiment myself.
snakes on a plane.gif
Snakes on a plane! || Gif from this video.

Works cited

Papers cite their sources throughout the paper, especially in the introduction. If I want to know where a particular fact came from, I’ll look at the citation in the works cited section, and look up that paper.

Acknowledgement/Conflicts of Interest

Science is objective, but humans aren’t. If your paper on “how dairy cows are super happy on farms” was sponsored by the American Dairy Association and Dairy Council, consider that the researchers would be very biased to come to a particular conclusion and keep receiving funding. If the researchers were employed by the American Dairy Association and Dairy Council, I’d be very tempted to just throw out the study.

Science for Non-Scientists: How to find scientific literature

Scientific journal writing has a problem:

  1. It’s the major way scientists communicate their findings to the world, in some ways making it the carrier of humanity’s entire accumulated knowledge and understanding of the universe.
  2. It’s terrible.

This has two factors: Accessibility and approachability. Scientific literature isn’t easy to find, and much of it is locked behind paywalls. Also, most scientific writing is dense, dull, and nigh-incomprehensible if you’re not already an expert. It’s like those authors who write beautiful works of literature and poetry, and then keep it under their bed until they die – only the poetry could literally be used to save lives.  There are systematic issues with the way we deal with scientific literature, but in the mean time, there are also some techniques that make it easier to deal with.

This first post in this series will discuss accessibility: how to find papers that will answer a particular question or help you explore a subject.

The second post in this series discusses approachability: how to read a standard scientific journal article.


How to Find Articles

Most scientific papers come from a small group of researchers who do a series of experiments on a common theme or premise, then write about what they learned. If your goal is to learn more about a broad subject, ask yourself if a paper is actually what you want. Lots of quality, scientifically rigorous information can be obtained in other ways – textbooks, classes, summaries, Wikipedia, science journalism.

 

blog science stack
The great food web of “where does scientific knowledge come from anyways?”

When might you want to turn to the primary literature? If you’re looking at very new research, if you’re looking at a contentious topic, if you’re trying to find a specific number or fact that just isn’t coming up anywhere else, if you’re trying to fact-check some science journalism, or if you’re already familiar enough with the field that you know what’s on Wikipedia already.

You can look at the citations of a journal article you already like. Or, find who the experts in a field are (maybe by looking at leaders of professional organizations or Wikipedia) and read what they’ve written. Most science journalism is also reporting on a single new study, which should be linked in the article’s text.

If you have access to a university library, ask them about tools to search databases of journal articles. Universities subscribe to many reliable journals and get their articles for free. Your public library may also have some.

Google Scholar is a search engine for academic writing. It has both recent and very old papers, and a variety of search tools. It pulls both reliable and less reliable sources, and both full-text and abstract-only articles (IE, articles where the rest is behind a paywall.) Clicking “All # Versions” at the bottom of each result will often lead you to a PDF of the full text.

If you’ve found the perfect paper but it’s behind a paywall- well, welcome to academia. Don’t give up. First up, put the full name of the article, in quotes, into Google. Click on the results, especially on PDFs. It’ll often just be floating around, in full, on a different site.

If that doesn’t work, and you don’t have access through a library, well… Most journals will ask you to pay them a one-time fee to read a single article without subscribing. It’s often ridiculous, like forty dollars. (Show of hands, has anyone reading this ever actually paid this?)

But this is the modern age, and there are other options. “Isn’t that illegal?” you may ask. Well, yes. Don’t do illegal things. However, journals follow two models:

  1. Open content access, researchers pay to submit articles
  2. Content behind paywalls, researchers can submit articles for free

As you can see, fees associated with journals don’t actually go to researchers in either model. There are probably some reasonable ethical objections to downloading paywalled-articles for free, but there are also very reasonable ethical objections to putting research behind paywalls in general.

How good is my source?

Surprise! There’s good science and bad science. This is a thorny issue that might be beyond my scope to cover in a single blog post, and certainly beyond my capacity to speak to every field on. I can’t just leave you here without a road map, so here are some guidelines. You’ll probably have two goals: avoiding complete bullshit and finding significant results.

Tips for avoiding complete bullshit

  • Some journals are more reliable than others. Science and Nature are the behemoths of science and biology (respectively), and have extremely high standards for content submission. There are also other well-known journals in each field.
  • Well-known journals are unlikely to publish complete bullshit. (Unless they’re well known for being pseudoscience journals.)
  • You can check a journal’s impact score, or how well-cited their work tends to be, which is sort of a metric for how robust and interesting the papers they publish are. This is a weird ouroboros: researchers want to submit to journals with high impact scores, and journals want to attract articles that are likely to be cited more often – so it’s not a perfect metric. If a journal has no impact score at all, proceed with extreme caution.
  • Watch out for predatory journals and publishers. Avoid these like the plague, since they will publish anything that gets sent to them. (What is a predatory journal?)
  • Make sure the journal hasn’t issued a retraction for the study you’re reading.

Once you’ve distinguished “complete bullshit” from “actual data”, you have to distinguish “significant data” from “misleading data” or “fluke data”. Finding significant results is much tougher than ruling out total bullshit – scientists themselves aren’t always great at it – and varies depending on the field.

Tips for finding significant results

  • Large sample sizes are better than small sample sizes. (IE, a lot of data was gathered.)
  • If the result appears in a top-level journal, or other scientists are praising it, it’s more likely to be a real finding.
  • Or if it’s been replicated by other researchers. Theoretically, all research is expected to replicate. In practice, it sometimes doesn’t, and I have no idea how to check if a study has been replicated.
  • If a result runs counter to common understanding, is extremely surprising, and is very new, proceed with caution before accepting the study’s conclusions as truth.
  • Apply some common sense. Can you think of some other factor that would explain the results, that the authors didn’t mention? Did the experiment run for a long enough amount of time? Could the causation implied in the paper run other ways (EG, if a paper claims that anxiety causes low grades: could it also be that low grades cause anxiety, or that the same thing causes both anxiety and low grades?), and did the paper make any attempt to distinguish this? Is anything missing?
  • Learn statistics.

If you’re examining an article on a controversial topic, familiarize yourself with the current scientific consensus and why scientists think that, then go in with a skeptical eye and an open mind. If your paper gets an opposite result from what most similar studies say, try to find what they did differently.

Scott Alexander writes some fantastic articles on how scientists misuse statistics. Here are two: The Control Group is Out of Control, and Two Dark Side Statistical Papers. These are recommended reading, especially if your subject is contentious, and uses lots of statistics to make its point.


Review articles and why they’re great

The review article (including literature reviews, meta-analyses, and more) is the summary of a bunch of papers around a single subject. They’re written by scientists, for scientists, and published in scientific journals, but they’ll cover a subject in broader strokes. If you want to read about something in more detail than Wikipedia, but broader than a journal article – like known links between mental illness and gut bacteria – review articles are a goldmine. Authors sometimes also use review articles to link together their own ideas or concepts, and these are often quite interesting.

If an article looks like a normal paper, and it came from a journal, but it doesn’t follow the normal abstract-introduction-methods-discussion-conclusion format, and subject headings are descriptive rather than outlining parts of an experiment, it might be a review article. (Sometimes they’re clearly labelled, sometimes not.) You can read these the same way you’d read a book chapter – front to back – or search anywhere in it for whatever you need.

What if you can’t find review articles about what you want, or you need more specificity? In that case, buckle up. It’s time to learn how to read an article.