Inductive vs. Deductive Reasoning

Inductve Reasoning is defined as "creating general principles by starting with many specific instances" (naked science). The example we used in class involved taking many different triangles of all different shapes and sizes and realizing that they all have a sum or 180 degrees for their internal angles. From this we induced that all triangles have internal angles that add to be 180 degrees.

Deductive reasoning is defined as "arriving at a specific conclusion based on generalizations" (naked science). These tend to be the If, then, but, therefore statements. An example from nakedscience.org is this. It is hypothesized that the color of a mineral is determined by its crystal structure. This hypothesis can be tested using deductive reasoning. "If the color of a mineral is determined by its crystal structure; then all purple minerals should have the same crystal structure. But purple amethyst has a hexagonal structure and purple fluorite has an isometric structure (determined by observations). Therefore, the hypothesis is not supported or strengthened" (naked science).




http://www.nakedscience.org/mrg/Deductive%20and%20Inductive%20Reasoning.htm