Netto-Induction

 Some Basic Forms of
Induction

Evidentiary Reasoning - treats evidence as traces or indexes of a likely, though not strictly valid, conclusion.
Evidence: A Evidence: B Evidence: C Evidence: D Conclusion: P	The butler had motive for murder The butler had means for murder The butler had opportunity for murder The butler has spots of blood on his shoes The butler committed the murder.

Analogical Reasoning - the hypothetical extention of a pattern perceived in a string of evidence to a comparable (analogical) case. This is the inductive reasoning deployed by criminal profilers to establish their hypotheses
Premise: X is P and Y is P Premise: X is Q and Y is Q Premise: X is R Conclusion: Y is likely to be R	All known murderers have motive and our suspect has motive. All known murderers have opportunity and our suspect has opportunity. All known murderers have means. Therefore, our suspect should have means.

Partial Confirmation of a Hypothesis - this has the same basic form as a species of non sequitur fallacy that we will call "affirming the consequent." It differs from that fallacy chiefly in its use of a qualifier to create a hypothetical (inductive) conclusion, rather than a deductively valid conclusion.
Premise: If P then Q Premise: Q Conclusion: P is likely, or at any rate possible.	If the butler is guilty then his alibi won't hold water. The butler's alibi doesn't hold water. It is likely, or at any rate possible, that the butler is guilty.