This publication presents changes and modifications for 2006-2007 to the "International Rules for Precollege Science Research: Guidelines for Science and Engineering Fairs." It is written to guide fair directors, teachers, scientists, parents, and adult volunteers as they pursue their work of encouraging students to explore and investigate their world through hands-on research. Change categories include: (1) General; (2) Hazardous Chemicals, Activities or Devices; (3) Human Subjects; (4) Form Changes. In addition to providing the rules of competition, these rules and guidelines for conducting research were developed with the intent to do the following: (1) protect the rights and welfare of the student researcher and human subjects; (2) protect the health and well-being of vertebrate animal subjects; (3) follow federal regulations governing research; (4) offer guidance to affiliated fairs; (5) use safe laboratory practices; and (6) address environmental concerns.