If the results are comparable, then the test is reliable. The split-half method, consists of splitting the tests into two halves, and making two different tests with them. Then we can compare the results from part one and part two. Validity means that the test measures what it's supposed to measure. To see if an intelligence test is valid, we should prove that it actually measures intelligence.
Face validity consists of the observation of the items within to determine their relevancy.
Factorial one uses factor analysis, which is a complex statistical procedure. If, in general, the students who do well on school examinations are the ones with the higher scores in the test, then we can say the test accurately measures intelligence. There are two forms of empirical validity, depending on whether the information about the criterion is available at the time of the test, or afterwards. These two forms are concurrent validity and predictive validity. For example, school performance is affected by many more factors, apart from intelligence.