The other day, I was browsing the internet, and I found this article about flying snakes!
Flying snakes!!
And I was like, "Whoa!" and also like, "How do they do that?"
So this article was published in The New York Times and it's interesting, right?
But it's, like, not the original research... like, the scientists who did the experiments
to figure out how snakes fly, like, they didn't publish their research in The New York Times.
That article where they published their research? That is here. The New York Times actually links to
it. This is the article where the researchers say, "We did these experiments and here's what we found
and here are the conclusions that we make."
We call this a "primary literature paper" because it came first.
The New York Times couldn't know how snakes fly without scientists doing experiments to figure it out, right?
Now, when scientists do experiments to figure something out, they could just like, walk around with that new knowledge, like,
"Haha... I know how snakes fly and you don't" but scientists don't do that, okay? They want to share their knowledge with other scientists, with the rest of the world,
and the way they do that is, they write a lab writeup. Like, literally, like, if you ever wrote a lab writeup in school, it's like, exactly the same
thing. There's an introduction, materials and methods, like, here are the data/results section,
uh, conclusion section, like, scientists literally write that.
Now, they could just publish that on the internet, right, like anybody can publish anything on the internet, but you know,
not everything on the internet is really...
...trustworthy...?
So what they do instead, is, they send it to a scientific journal. In the scientific journal, the people of the scientific journal,
they may not be experts on how snakes fly, like, they can't really tell if this is, like, really trustworthy science or not.
So what they do, is they send it to scientists who can tell - other people who are experts in the field.
Those scientists (we call them the Reviewers).
The reviewer's job is to be skeptical.
So maybe what they'll do is, they say, "You know, this is an interesting conclusion, but, I think it would be stronger -
I'd be more convinced - if you did a couple other experiments.
So, the journal will send those reviews, those comments, back to the scientists and the
scientists will do those other experiments, and then they will write up a new draft,
and they'll send it to the scientific journal, and the scientific journal will publish it. Okay, that
is what we call "peer review" and every primary literature scientific article is peer-reviewed.
So other scientists review it to make sure that it sort of makes sense, that the conclusions are supported by the data.
So, a primary literature article, unlike the New York Times article, is:
published in a scientific journal,
peer-reviewed,
written by the scientists who did the experiments,
and it's about the experiments that they did.
It reports the data that they discovered by doing the experiments.
Now, the New York Times article is less about the data. They're not going to show you the data.
It's more about the conclusions, right, like the "Wow! Now we know how snakes fly!"
That type of article is called a "secondary literature article", because it comes second, right? They can't publish it without the primary literature article being published first.
Okay, so let's say you find an article on the internet and you're like, "Is this a primary literature article?"
How do you tell?
The quick-and-easy way to do it is to look for an "abstract". The abstract is like the "tl;dr" version of the paper, like, one paragraph, "Here's what we did and what we found".
All scientific articles have abstracts. They are always available.
I say that because there are a lot of journals that keep their articles behind a paywall.
Don't get me on my high-horse about that, because it's a problem in science. Anyway.
You'll always have access to the abstract. So if it has an abstract, it's a scientific paper.
Scientific journals publish two different types of papers, generally.
There's "primary literature papers" (what we've just been talking about) and there are "review articles".
Review articles are published in a scientific journal. They're peer-reviewed and they're written by scientists.
What they are, is: when a scientist reads a whole lot of primary literature papers,
or a couple scientists, they'll synthesize it all into one big picture for you.
So, primary literature articles are really, really focused. They're on a particular problem and they're like
building blocks, okay, and the people who write review articles, they're scientists in the field.
And they read all the primary literature papers, and they say, "Hmm, what does that all mean?"
So the review article is, like, stepping back. It's like the big picture of, like,
where the field has been for the last few years and, like, where they think it's going.
The review articles are, like, super useful but they are not primary literature articles.
So how can you tell the difference if you find a paper that has an abstract, how do you know
whether it's a review article or a primary literature article? There are a couple ways.
First of all, just look to see if there's the word "review" somewhere. Okay, so sometimes it'll just
be listed on there it's a review article. By the way, just because it doesn't say "review" doesn't mean it's
a primary literature article. Sometimes they just don't advertise "review". So here's a couple other
things you can look for. One: look at the title. If the title is: really specific, kind of long,
maybe hard to understand, it's probably a primary literature article. If the title is short and
generic, it's probably a review article. That's not always true, but it's generally true. The
other foolproof way is to look for data, because, remember that primary literature articles are
about experiments and they report data and that's the big difference between a primary literature
article and a review article. So, if you see signs of data, like, figures with graphs and pictures,
then that's a primary literature article. Now you might not always have access to the paper,
because papers are behind paywall sometimes, so you can do some sleuthing in the abstract. So
if in the abstract they say something like, "We tested, or, we analyzed, or, we assessed, and
they were doing something - they were generating data - that's the primary literature paper. If,
on the other hand, they say, "We review, or, we summarize, then that's a review article.
So the reason I'm so excited about primary literature articles, is that, you yourself get to
make your own conclusions. You don't have to rely on an expert to interpret it for you, because the
data are right there. You can look at the data and interpret it yourself. Now, in the beginning when
you start reading primary literature articles, it's hard. Like it's hard to understand.
But the more you read, the easier it gets, and the savvier you'll get at making your own conclusions.
By the way, that snake paper - super cool - they don't actually fly, they glide, from treetop to treetop.
They live in Southeast Asia and they're not venomous to humans, so don't worry about them.
What they do when they fly, they actually undulate their bodies like when they're swimming or when
they're, like, steering across the sand... They do that, so that they don't roll over, so that they
can land upright. It's super cool, I recommend you check it out. I've put it down in the description.
Share with me in the comments your favorite primary literature article, because I love
reading primary literature. And hit the subscribe button. I hope to see you in my next video!