Peer Review – a process by which something proposed (as for research or publication) is evaluated by a group of experts in the appropriate field. – Merriam-Webster Dictionary

Over the weekend, Brian Angliss posted a piece over at Scholars and Rogues on why scientific peer review matters. He wrote it in response to climate change deniers who like to argue that peer review is useless and therefore, just because climate science is peer reviewed, it isn’t necessarily true.

Unfortunately for the denier community, it’s a little more complicated than that. As Angliss writes:

One major misconception about all varieties of peer review is that the reviews guarantee no errors in the final product.

What peer review does is start a process of finding and correcting errors, which generally continues upon and after publication, Angliss explains. It is another step in the scientific method of gathering data and testing hypotheses to solve a problem or understand an issue. Because of this method, scientific understanding often builds and deepens over time. That does not make the original assumptions or theories incorrect.

Case in point, a recent series on NPR on Charles Darwin’s theory of evolution points out that Darwin was correct in ways that he himself could not have understood at the time.

It should go without saying that peer review can also serve to keep anyone with a theory and enough money from ExxonMobil from passing it off as scientifically sound. Unfortunately, this hasn’t been the case as media outlets like the New York Times and Washington Post continue to behave as if climate change science has two sides to it by treating self-proclaimed authorities on global warming like Marc Morano as if they actually have a right to that title or to be taken seriously. As Angliss writes:

After all, anyone can publish a blog filled with so many numbers that it looks legitimate, but only a scientist would subject him or herself to peer review.

In this way, peer review can also be used to pass off bad science, which is why there needs to be an understanding that peer review is only part of the process and evolves over time. It is also why the media ought to play a greater role in pointing out legitimate, independent criticism of scientific theories that have passed peer review, while separating peer reviewed science from mere opinion.

Differing opinions on a range of topics, from the best city for pizza (Chicago, how is there even a debate?) to whether dogs or cats make better pets (um, anyone with a dog knows the answer) keep the world interesting. But science is not opinion. Science is an understanding of the evidence of something to the best of our ability. Science is about facts, tested and retested, against a set of assumptions. Peer review is imperfect, and not everything that gets through the process is without flaws. Peer review may also slow down the process of moving from theory to actionable understanding. However, it is the first lines of defense in separating opinion from fact. And until the media stops giving credence to people with opinions passing them off as scientifically-based, it may be the only line of defense.