For EB2 - Exceptional Ability Criteria including NIW, you need to meet at least 3 criteria of the following 6:
(1) An official academic record showing that the alien has a degree, diploma, certificate, or similar award from a college, university, school, or other institution of learning relating to the area of exceptional ability;
(2) Evidence in the form of letter(s) from current or former employer
(3) A license to practice the profession or certification for a particular profession or occupation;
(4) Evidence that the alien has commanded a salary, or other remuneration for services, which demonstrates exceptional ability;
(5) Evidence of membership in professional associations; or
(6) Evidence of recognition for achievements and significant contributions to the industry or field by peers, governmental entities, or professional or business organizations. http://www.greencardapply.com/niw/niw_requirement.htm
http://www.greencardapply.com
http://www.greencardfamily.com