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Case analysis may refer to

Proof by cases in mathematics
Study of the best, worst and average cases
Case study, detailed examination of a subject
The case method used in teaching

This disambiguation page lists articles associated with the title Case analysis.
If an internal link led you here, you may wish to change the link to point directly to the intended article.

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+'''Case analysis''' may refer to
-{{for|the rule of inference propositional logic which expresses Case analysis|Disjunction elimination}}
-{{Unreferenced|date=December 2009}}
+* [[Proof by cases]] in mathematics
-'''Case analysis''' is one of the most general and applicable methods of analytical thinking, depending only on the division of a problem, decision or situation into a sufficient number of separate cases. Analysing each such case individually may be enough to resolve the initial question. The principle of case analysis is invoked in the celebrated remark of [[Sherlock Holmes]], to the effect that when one has eliminated the impossible, what remains must be true, however unlikely it seems.
+* Study of the [[best, worst and average case]]s
+* [[Case study]], detailed examination of a subject
+* The [[case method]] used in teaching
-The logical roots of the Holmes remark speak to the principle of [[excluded middle]]. That indicates the importance to case analysis of [[logical disjunction]]: stringing together propositions with the [[logical connective]] ''"or"''. [[Medical diagnosis]] can indeed follow the Holmes pattern, with a patient's symptom possibly caused by a number of conditions: the patient suffers from ''A'' or ''B'' or ... or illness ''I''; see [[differential diagnosis]]. [[Deductive logic]] is applied to reducing the number of cases; see [[case-based reasoning]].
+{{DEFAULTSORT:Case analysis}}
-A canonical statement of case analysis in the sentential calculus is this:
+{{disambiguation}}
-"If a statement ''P'' implies a statement ''Q'', and a statement ''R'' also implies ''Q'', and at least one of ''P'' or ''R'' is true, then ''Q'' must be true."
-: <math>(((P \rightarrow Q) \land (R \rightarrow Q)) \land (P \vee R)) \rightarrow Q \, </math>
-==Exhaustive analysis==
-The most important issue in this style of case analysis is that the cases should be collectively ''exhaustive'': everything is covered. The condition that they should be ''exclusive'', while convenient, is not to be assumed lightly; for example a patient's liver problem might be caused by [[hepatitis]] ''and'' abuse of alcohol, with one factor not ruling out the other. This points up the distinction between [[exclusive or]], and logical disjunction which is the default meaning of 'or' (in logic, mathematics and science) and which is non-exclusive. Case analysis of the non-overlapping kind is a special case, only.
-==Other terminology==
-'''Case-by-case analysis''' is a more specific term for such a pinning-down of cases. It assumes a situation in which a thorough-going case analysis can be completed: all cases covered and resolved. This is not always realistic. Other forms of case analysis are [[best case analysis]] and [[worst case analysis]], scenarios for the optimist and pessimist, respectively.
-Two names for approaches that take complete case-by-case analysis as not meeting the needs of the topic under consideration are [[casuistry]], most often in [[ethics]], and the [[case study]] method used in business schools.
-==See also==
-*[[Mutually exclusive]]
-*[[Collectively exhaustive]]
-*[[Pattern matching]]
-*[[Proof by exhaustion]]
-{{DEFAULTSORT:Case Analysis}}
-[[Category:Methods of proof]]
-[[Category:Theorems in propositional logic]]