Definition
Deduction
A deduction is a conclusion that must follow from the facts and rules already given.
What it means
A deduction is not a lucky guess. Put the facts in order and ask what they force. When every allowed case leads to the same conclusion, you have deduced it.
Remember it
Facts are tracks: a deduction is where the tracks have to lead.
Example
Every red card in a set is a triangle. Card A is red. Therefore Card A must be a triangle. The conclusion is forced by the two stated facts.
Watch for
A conclusion that seems likely is not yet a deduction. The facts must make every other conclusion impossible.
Common mix-up
Deduction moves from rules and facts to a necessary conclusion. Inductive reasoning uses examples to suggest a rule that may still need proof.
Exact meaning
A deduction is a conclusion obtained by valid reasoning from stated facts, definitions, or established results. If those starting statements are true, the conclusion cannot be false.