What is “Peer review” and why is it so important to science?
The goal of the scientific process is to discover things that no one knew before and push the frontiers of knowledge. How do we do this?
Well, first, remember, nobody is perfect. Scientists make mistakes and can sometimes fool themselves into thinking they are right, when they are not. But still….the scientific process usually finds its mistakes and yields more accurate results than most other fields for two reasons:
1) Self-skepticism
2) The peer review system
Most scientists are skeptics. A good scientist is skeptical of their own results, always double checking and trying to find their own mistakes or fallacies. As I tell my students, “You want to be the one to find your own mistakes, not someone else.” The peer-review system is a critical element of the scientific process. All potential papers and grant proposals will get reviewed by other experts in the field. Usually the process is anonymous, so that the person being reviewed does not know who were the reviewers. In this way, the reviewers can be honest in their reviews. The system isn’t perfect, but it’s better than nothing. Actually a lot better.
Consider what would happen if the used car salesman had to go through peer review: “Folks, this car has brand new tires, the engine is in perfect running condition, and the transmission is brand new. It’s a great deal at only $14,000.” Do you accept the salesman’s claims? If you do, you might end up with a junker for a lot of money! So if you are smart, you get an outside mechanic or expert to evaluate the salesman’s claims. That’s the basic idea of peer review. We ask an outside expert with no financial connection to the transaction to provide an unbiased review.
In the scientific arena, a scientist submits their work to a journal and the journal editor sends the paper out to 2–3 experts for anonymous review. Typically, journals publish anywhere between 20–80% of the papers that are submitted, depending on the journal. Some are much more selective than others. I’ve been through the review process on both sides literally hundreds of times (for every paper and grant proposal I’ve ever submitted). I am also a journal editor, so I’m familiar with some of the challenges and problems that can come up with the process. Peer review can be harsh, especially for young scientists, so it’s important for mentors to help them through the process until they get used to it.
As you know, I love cartoons, especially science cartoons. Here are two good ones about peer review. The first one shows the traditional white male scientist submitting his paper.

I also like the modified version of this cartoon, which has a younger female scientist going through the process. I found this cartoon at https://www.sciencematters.io.
The process is harder for young, female, or minority scientists, who are not part of the “old boys’ club”. I’ll have a blog post later on diversity and sexism and harassment issue in STEM. It’s a serious matter that we all need to address.
