If you listen to scientists for long, you’ll hear them referring to “the literature” or using terms like “scientific consensus”. “Literature” and “consensus” are fairly common words, but there’s some nuance in the way that scientists use them that can be confusing if you’re not familiar with it. In this post, we’ll define those terms in a way that considers the scientist’s nuance. We’ll also talk about the different forms of scientific literature and briefly discuss the scientific process.
What is “scientific
literature”?
Quite broadly (more so than most scientists would define it),
scientific literature is anything
written about science. However, when
scientists use the term, they’re usually referring to a specific subset of
scientific literature that includes review articles and original research
articles (defined below). So, in order to understand the term “scientific
literature” as scientists use it,
we’re going to have to define the subsets of that literature. In this section,
I’m borrowing heavily from a document created by my colleague, Nathan Mills,
that we use to teach our students about the designations of the literature. We
can loosely group scientific literature into two categories – primary literature
and secondary literature.
Secondary literature
Secondary literature is usually written by a person who did
not conduct the original research being communicated. It may or may not undergo
the process of peer review (a process I hope to write a whole post on later,
but which entails a critical reading by other scientists pre-publication.
Publication is largely contingent on the approval of the peer reviewers). Some
categories of secondary literature include:
Popular and technical books
Popular books have the advantage of being really fun to
read. They are a great introduction to a broad area of science or to science in
general. They are often written by an expert in the field and are intended to
interest, excite, and educate the general population. They do not, however,
undergo the process of peer review. They are not intended to deeply contribute
to the scaffolding used for experimental design, to communicate specific data,
or to be used in the process of decision-making by medical personnel or by
scientists. I like to read popular books when I want an engaging introduction
to an area of science I’m less familiar with.
Textbooks
Textbooks have the advantage of being concise summaries of
the state of the field. They often provide an excellent foundational knowledge
of the scientific process and of our current knowledge surrounding scientific
phenomena. They may communicate and summarize some specific experimental data,
but do not often communicate the entire scientific process for the generation
and assessment of those data. I teach from textbooks often, and I like to use
them as a quick reference to remind myself of specific well-established rules
and facts.
Popular magazines
I really like to read these articles to grab a quick summary
of what’s currently being done in many areas of science. Very often, they’ll
link to the original published study, so if I’m intrigued by the topic, it’s
easy to dig deeper. However, these articles frequently overstate the findings
in the articles they summarize, so it’s good to take them with a large grain of
salt.
Review articles
Review articles are generally written by a very small number
of invited top experts in a specific subset of science, and summarize the
current data and theory in that area. Review articles undergo rigorous peer review
and are published in peer reviewed journals.
Review articles are an excellent way to get a detailed “lay
of the land” for a specific area of science. I just skimmed one the other day
summarizing our current understanding of the contributions of calcium ions to
mitochondrial function. I heavily utilize review articles when I am delving
into an area of science that’s less familiar to me than my own specific area of
expertise. Review articles reference a large number of original research
articles and serve as a crucial launchpad as I survey the field and select key
studies to read as I begin my exploration.
Primary literature
Original research
articles
These articles are the “bread and butter” of scientific literature, because theoretical framework, experimental design, and results are communicated by the scientists who conducted the experiments. They are rigorously peer reviewed, and focus on the investigation of a very specific question in a specific subset of science. They typically contain an abstract which briefly summarizes the article, an introductory section which briefly summarizes the field prior to the conducting of the study and sets up the framework for the question addressed by the experiments communicated in the article, a materials and methods section which communicates the research methods used to address the question, a results section which reports the data obtained from the experiments, a discussion section in which the results are interpreted and placed into the larger framework provided in the introduction, and a literature cited section in which any referenced publication is listed with a complete citation.
Reading original research articles is the only way to really
dig deeply into the rationale, experimental design, and conclusions surrounding
a specific scientific question. All good scientists consult original research
articles regularly during the course of their career.
The “downside” to original research articles is that they
are written to a specific audience: other research scientists in the same
field. To read, understand, and critically and accurately assess an original
research article requires practice, dedication, focus, and training. Most lay
people will not find original research articles to be accessible and will
become bored, confused, and frustrated while reading them.
So, who do I trust?
Many people are currently struggling to decide who to trust
when it comes to scientific and medical information. The advent of social media
has resulted in ease of access to information, but has also led to information
fatigue. It’s helpful if you know a scientist (like yours truly) who can
quickly assess a source for you and let you know if it’s a good one or not. I
assess original research articles on a one-by-one basis – do their questions
make sense given the background they provide? Did they set up appropriate
experiments to address their questions? Did they use the appropriate
statistical analyses to assess their data? Do the data actually say what the
authors say they say?
While a few will have the interest and motivation to develop
their ability to read and assess original research, many don’t have time or energy
to do so and need to rely on information that comes in the form of secondary
scientific literature, often at the level of popular magazines, op-eds, or even
blog posts. So, what then? A good rule of thumb if your goal is to make decisions
based on the best information available is to follow and read sources that fall
in line with current “scientific consensus,” which we’ll address next. It’s
certainly ok to read things that challenge current scientific consensus, but
following scientific consensus is most likely to put you in line with the best
information currently available.
What is “scientific
consensus”?
I read a blog post last year that, in an attempt to
disparage scientists working on SARS-CoV-2, defined scientific consensus as
synonymous with a “vote” or a “popularity contest”. This couldn’t be further
from the truth, but it seems to be a relatively popular opinion among
non-scientists.
So, if “scientific consensus” isn’t the same thing as a vote
or a popularity contest, what is it? Scientific
consensus is reached when multiple, independent experiments result in an
accumulation of data that consistently support a common conclusion. There’s
no governing body of scientists that sits down and calls a vote on whether or
not we’re going to adopt a conclusion as fact. When scientists talk about
scientific consensus, we mean that a large body of literature exists which
supports a given conclusion. The larger the body of literature and the more
rigorous the experimentation, the stronger the consensus.
Scientific consensus does not reflect the whole truth of
what is happening in the physical or natural world around us. If it did, we
wouldn’t need to continue conducting research because we would know everything
there is to know about the world in which we live. However, those who wish to
challenge scientific consensus should do so with
sound experimental evidence. If the challenging hypotheses are correct,
they will ultimately be supported by a plurality of well-conducted studies and
scientific consensus will shift to reflect updated knowledge.
I know I hit you with a lot of information at once in this
blog post. Comment below and ask questions you have about the things in this
post or let me know what you’d like to hear about next.