Quick questions on Inductive arguments and strength explained: H2 Knowledge and Inquiry

Inductive arguments are not valid or invalid; they are strong or weak, and strength comes in degrees. An inductive argument is strong if its premises, were they true, would make the conclusion highly probable, and weak otherwise. A strong inductive argument whose premises are actually true is called cogent, the inductive counterpart of a sound deductive argument. So the evaluative pair for induction is strength and cogency, mirroring validity and soundness for deduction.

An analogical argument infers that because two things are alike in some respects, they are alike in a further respect. Its strength depends on the number and relevance of the similarities and the absence of relevant differences. Analogy is powerful for generating hypotheses but easily abused: a single striking similarity rarely supports a strong conclusion if the relevant differences are large.

A third form reasons from a body of evidence to the hypothesis that best explains it: the patient has these symptoms, and the diagnosis that best accounts for them is X, so probably X. Its strength depends on how much better the favoured explanation is than its rivals, judged by criteria such as explanatory scope, simplicity, and fit with background knowledge. This form is central to science and to detective-style reasoning, and it underlies the scientific-method debates in the sciences area.

Explain why an inductive argument can have true premises and a false conclusion without being a bad argument. [6 marks]

State two factors that make an enumerative generalisation strong. [6 marks]

Explain what inference to the best explanation is and one criterion for judging which explanation is best. [8 marks]