Scientific Reasoning

What is Science? Testing hypotheses about the world with data Performing experiments that control alternative causes in order to make causal attributions Scientists must do causal reasoning –Generate theories –Test theories

The Cycle of Science Scientific reasoning must use both inductive and deductive reasoning

Confirmation bias The Wason task –People are told that the sequence satisfies a particular rule and are asked to determine the rule by generating other 3-number sequences as tests. Scientists also show a confirmation bias –Koehler showed that scientists are more critical of findings that do not fit with their theoretical beliefs than of findings that do fit with their beliefs. Studies designed to disconfirm are important

Studying Scientific Reasoning Case studies –How do actual scientists reason? –Dunbar did studies in real microbiology labs Scientists use analogies to form theories, generate hypotheses, and comprehend patterns of data Analogies tend to be “close analogies” –Weisberg has looked historical cases purported to show great insight. Kekule and the benzene ring Debunking the “Brazil” model of the unconscious

Experimental Control Scientists work to create experimental control –Hold constant the effects of alternative causes across experimental groups People in general seem to recognize that this is a good strategy for assessing causes –Fits with everyday reasoning people do –Experimental studies demonstrate that even young children try to adopt this strategy

Mental simulation Scientists get a lot of mileage out of mental simulations used as “intuition pumps.” –Einstein and light What happens as the moving cart approaches the speed of light?

Scientific Reasoning Scientists are people too People are scientists too Reasoning processes in people and scientists are similar –Scientists are more systematic than people in general More tools Better notes More need for consistency