This is one of three reports (Including The Contributions of Teacher Leaders and The Work of Teacher Leaders) wrriten by Inverness Associates on the California Subject Matter Projects (CSMP). "The CSMPs consist of nine Projects providing professional development in nine different disciplines...at 101 regional sites--all of which are designed to attract, develop, nurture, sustain, and promote teacher leadership." This report primarily focuses "on understanding the realities of teacher leadership: what motivates teacher leaders' what sources of knowledge they draw upon in working with their colleagues; what supports they find most useful, what issues and barriers they face."