Education Law Section 3012-c requires a new performance evaluation system for classroom teachers ("teachers") and building principals ("principals"). New York State will implement a statewide comprehensive evaluation system for school districts and boards of cooperative educational services (BOCES). The evaluation system is designed to measure teacher and principal effectiveness based on performance, including measures of student achievement and evidence of educator effectiveness in meeting New York State teacher or school leader standards. The new statewide evaluation system established by section 3012-c builds on, and does not eliminate, New York's existing APPR process, which is set forth in Section 100.2(o) of the Commissioner's regulations. The purpose of this guidance is to answer questions that educators, administrators, and community stakeholders may have about Education Law Section 3012-c (Chapter 103 of the Laws of 2010) and Section 100.2(o) and Subpart 30-2 of the Commissioner's regulations. (Contains 4 tables and 1 footnote.)