The answer is type II error. This happens when the null hypothesis is false, however wrongly neglects to be rejected. It is neglecting to affirm what is available, a miss. A sort II blunder might be contrasted and a purported false negative (where a real 'hit' was neglected by the test and seen as a 'miss') in a test checking for a solitary condition with a complete consequence of genuine or false. A Type II mistake is submitted when we neglect to a true alternative hypothesis.
