Comment by BizarroLand

That's why the term "Garbage In, Garbage Out" exists.

In any non-edge case (that is, where the system is operating in ideal conditions and no flaw or bug, known or unknown, exists in the system), a verifiably functioning computer will produce the exact same results for any process every time.

If the computer does not do what you expected it to do and spits out garbage, then you gave it garbage data.