Define the difference between a Type 1 and Type 2 error.

A type one error is often referred to as an optimistic error, this is because the researcher has incorrectly rejected a null hypothesis that was in fact true, they have been too lenient. A type two error is the reverse of a type one error, it is when the researcher makes a pessimistic error. This is where the researcher fails to reject the null hypothesis when it was false because in actual fact the alternative hypothesis was true, the researcher has been too stringent.