Scientific consensus has gotten a bad reputation—and it doesn’t deserve it

In a recent post, Senior science editor at Ars TechnicaJohn Timmer defends the importance of consensus.

Opening with the following quote from author Michael Crichton:

Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world. In science consensus is irrelevant. What is relevant is reproducible results.

Timmer defends the importance of consensus pointing out:

Reproducible results are absolutely relevant. What Crichton is missing is how we decide that those results are significant and how one investigator goes about convincing everyone that he or she happens to be right. This comes down to what the scientific community as a whole accepts as evidence.

Different fields use different values of what they think constitutes significance. In biology […] scientists are willing to accept findings that are only two standard deviations away from random noise as evidence. In physics […] five standard deviations are required.

Consensus matters because it “simply shapes the discussion.”

[A]ny idea in science carries the seeds of its own destruction. By directing research to the areas where there are outstanding questions, a consensus makes it more likely that we’ll generate data that directly contradicts it. It may take a little while to get recognized for what it is, but eventually the data will win out.

Probably the most talked about consensus revolves around climate change.

The Intergovernmental Panel on Climate Change produces assessment reports that summarize the latest knowledge in the field.

[P]eople have used a variety of methods—literature searches, polling of scientists, and so on—to measure the state of the consensus. Each of those attempts has put the consensus number for climate change in the area of 97 percent agreement.

A consensus definitely exists. Does that mean it’s right?

There have clearly been times in the past where the consensus wasn’t especially brilliant. Mendel was ignored instead of starting to build a consensus, and Alfred Wegner’s formative ideas about plate tectonics were roundly ridiculed. But it’s worth noting that these cases are the exception. The majority of the time, the consensus is a bit closer to being right than whatever came before it. And while it may be slow to change sometimes, it can eventually be shifted by the weight of the evidence.

Read the full post here.