The scientific method tests ideas with evidence. It is a process used to explore observations and answer questions. It doesn’t pretend to have all the answers, but it is a vehicle for finding answers. Sometimes questions have to be broken down and experiments have to be conducted multiple times to verify an answer or to rule out a hypothesis. Scientists in every field use the scientific method to answer questions: chemistry, physics, geology, psychology, medicine, biology, and more. The University of California at Berkeley has a wonderful explanation of how the scientific method works in both simple and complex situations.

If we think we know the answer to a question without testing the evidence, we are guessing or we are engaging in confirmation bias, which is our tendency to interpret new evidence to support our existing beliefs or theories. Everyone, regardless of how intelligent or open-minded, struggles with confirmation bias. We make the answer fit what we think it ought to be rather than looking hard at evidence and analyzing it. In every experiment, scientists try to eliminate confirmation bias. That’s why most of the world’s most significant discoveries start with “Huh. That’s strange,” instead of “Yeah, I thought so.”

Because it is driven by the evidence, science is self-correcting. When scientists get an answer, they continue to refine the problem and test hypotheses to make sure they’re right. When they get a different answer, they test that one, too, and analyze it against the results of other experiments – and sometimes to change the answers entirely. That’s how we came to change our notions about the structure of the solar system (the earth is not the center of the universe) and how disease and deformity happen (they are not caused by bodily humors or demonic possession, but rather germs and genetics). It’s hard to let go of answers that are “almost right” when they satisfy us, but as we discover new evidence, we have to tweak our conclusions.

With its “Misconception of the Month” series, the National Center for Science Education (NCSE) explains the nature of science and tackles common misconceptions about hot-button issues like climate change and evolution. NCSE belongs to the American Association for Advancement of Science (AAAS), the world’s largest multidisciplinary scientific society and a leading publisher of cutting-edge research through its Science family of journals. Founded in 1848, AAAS promotes cooperation among scientists, defends scientific freedom, encourages scientific responsibility, and supports science education and science outreach for the betterment of all humanity.