Deductive vs. Inductive Reasoning • The difference: inductive reasoning uses patterns to arrive at a conclusion (conjecture) (in most cases based on a pattern, observations it will happen 99. 999% of the time …) deductive reasoning uses facts, rules, definitions or properties to arrive at a conclusion. (like a detective – you have to Be sure it’s VALID, proven all logic

Examples of Inductive Reasoning *in most cases yes, but not ALWAYS 100%%% 1) Every quiz has been easy. Therefore, the test will be easy. 2) The teacher used Power. Point in the last few classes. Therefore, the teacher will use Power. Point tomorrow. 3) Every fall there have been hurricanes in the tropics. Therefore, there will be hurricanes in the tropics this coming fall.

Example of Deductive Reasoning An Example: The catalog states that all entering freshmen must take a mathematics placement test. You are an entering freshman. Conclusion: You will have to take a mathematics placement test.

Inductive or Deductive Reasoning? Geometry example… x Triangle sum property – the sum of the angles of any triangle is always 180 degrees. Therefore, angle x = 30° 60◦ Deductive Reasoning – conclusion is based on a property

Inductive or Deductive Reasoning? Geometry example… What comes next? Is there a rule? Colored triangle rotating 90° CW in the corners of the square Inductive Reasoning