When scientists set out to explore and explain natural phenomena, they often start with specific observations that highlight a particular question or problem. They then induce a possible answer or solution, known as a hypothesis. This type of logical thinking, which uses observations to reach general rational conclusions, is called inductive reasoning.

After a hypothesis has been established, scientists deduce that certain events should occur if the hypothesis is true. Researchers use these predictions, the result of deductive reasoning, to test the hypothesis. Compared to inductive reasoning, deductive reasoning works in the opposite direction, starting with general principles or laws (i.e., conclusions) and using them to predict specific results (i.e., future observations). Deductive tests are often formulated as “If...then” statements: if the hypothesis is true, then the prediction should be observed.

Although deductive reasoning is at the heart of hypothesis-driven science, whereas inductive reasoning is mostly associated with descriptive science, both forms of logic are integral to research and often tie in together within the same experiments.