Scientific Method Set of procedures by which scientists learn about the world

Marine Laboratories Woods Hole Mote Marine Laboratory Univ. Miami - RSMAS UC, Santa Barbara University of Georgia University of Georgia – Odum School of Ecology University of Georgia – Odum School of Ecology Univ. Rhode Island

The Scientific Method

Two Ways of Thinking Induction: one uses separate observations to arrive at general principles Deduction: reasoning from general principles to specific conclusions

Induction Because sailfish, sharks, and tuna are all fishes, all fishes have gills. General conclusions made on the basis of specific observations.

Deduction Suppose a marine biologist used induction to make the general statement: All marine animals have gills. That marine biologist might then reason that if all marine animals have gills and whales are marine animals, then whales must have gills.

Hypothesis A statement that might be supported by data. If (cause), then (effect) statement.

Hypothesis There are no absolute truths Scientists speak of accepting a hypothesis, never proving them Testing hypothesis: more confidence can be placed in a hypothesis that has stood up to the hard testing than in an untested one. Suggesting an alternative hypothesis. The nature of scientific proof:

Experiment Factors affecting observations: variables Controlled vs. experimental variable