The SSAT is written and reviewed by independent school educators, and content and assessment experts. Once a test question is written, it is thoroughly reviewed by a committee that reaches consensus regarding the question's appropriateness. It then goes through a rigorous standardized process to analyze the question and its answers. Once questions are proven statistically sound, they are assembled into test forms. The distribution of question difficulties is set so that the test will effectively differentiate among test takers who vary in their level of ability.