(1) Induction is the process of making general conclusions on the basis of the specifics. For example, if you notice while driving on Road I-75 that some drivers tailgate and some other people have come to the same conclusion, and a local website confirms the same conclusion about tailgating on I-75, then you can safely make an inductive claim saying that tailgating is a problem on I-75. To be valid and accepted, an inductive claim has to meet two requirements: use of sufficient examples, and reliability of sources that provide the examples. In the inductive claim above, there are three particulars that back up the inductive claim: your first hand experience, other people’s first hand experience, and the local website. Second, if the three sources are reliable, then the inductive claim is valid and accepted. In case we do not have sufficient sampling (examples or particulars), then the induction is not accepted because in this case, the induction will be more of a stereotyping or unsupported generalization.
(2) Deduction does not aim at reaching the truth as induction, but it rather tests the sound relationships between premises or statements. For example:
Major premise: All NBA players make a decent income.
Minor Premise: John is an NBA player
Conclusion: John makes a decent income.
The goal here is not to reach the truth as in induction, but to rather see if a logical, consistent relationship exists between the three statements. In other words, has the conclusion come out of the two premises? In this example, yes, the conclusion is the outcome of the two premises, but if the conclusion is not the outcome of the two premises, then the deduction becomes invalid and unacceptable as in the following example:
Major Premise: Tuition at Harvard is very high.
Minor Premise: John studies at Harvard.
Conclusion: John pays high tuition at Harvard.
To evaluate the above deduction, we need to judge whether or not relationship between the premises is consistent. First, the minor premise is not consistent with the major premise because it does not say if John is a tuition-paying student at Harvard. Second, the verb “study” can mean “read,” so it is possible that John goes to the Library at Harvard to read or study his subjects for another school, so there is a possibility that he is not a student at Harvard. Second, even if he is a student at Harvard, he can be on a scholarship, so he is not really paying tuition. Due to such inconsistency between the minor premise and the major premise, the conclusion is not valid.