The difference here is that an inductive argument takes one specific case and uses it to make a general argument that is supposed to apply more broadly. By contrast, a deductive argument takes one or more known facts or ideas and applies them to the case at hand.
For example, an inductive argument might go like this: World War II started while a Democratic president was in office. Therefore, we can see that having a Democratic president leads to war. (Reasoning from a specific incident to a general conclusion.)
By contrast, a deductive argument would say, for example: the party of the sitting president generally loses seats in Congress at the midterm election. Therefore, it is likely that the Democrats will lose seats in this midterm election. (Reasoining from a broader concept to a specific case.)
The key criteria for inductive arguments in establishing viable sample populations are:
- Is the sample known?
- Is the sample sufficient?
- Is the sample representative?