Sanity check

A sanity check or sanity test is a basic test to quickly evaluate whether a claim or the result of a calculation can possibly be true. It is a simple check to see if the produced material is rational (that the material's creator was thinking rationally, applying <a href="/facts/Sanity/oGRSfB5m">sanity</a>). The point of a sanity test is to rule out certain classes of obviously false results, not to catch every possible error. A <a href="/facts/Rule-of-thumb/RopfGsJ0">rule-of-thumb</a> or <a href="/facts/Back-of-the-envelope_calculation/oMsTryuL">back-of-the-envelope calculation</a> may be checked to perform the test. The advantage of performing an initial sanity test is that of speedily evaluating basic function.
In arithmetic, for example, when multiplying by 9, using the <a href="/facts/Divisibility_rule/y381b06v">divisibility rule</a> for 9 to verify that the <a href="/facts/Digit_sum/3xJXufJD">sum of digits</a> of the result is divisible by 9 is a sanity test—it will not catch every multiplication error, but is a quick and simple method to discover many possible errors.
In <a href="/facts/Computer_science/lN3pEyPz">computer science</a>, a sanity test is a very brief run-through of the functionality of a <a href="/facts/Computer_program/e38jH9N9">computer program</a>, system, calculation, or other analysis, to assure that part of the system or methodology works roughly as expected. This is often prior to a more exhaustive round of testing.

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Sanity check