Uribe-Zarain, Ximena2010-07-082010-07-082009-10-08http://udspace.udel.edu/handle/19716/5398This evaluation report, prepared by the Delaware Education Research and Development Center (R&D Center), includes a description of the performance of a group of mathematics teachers who participated in the School Based Teacher Leaders (SBTL) project from 2005 until 2009 in the state of Delaware. During five years trained observers from our center conducted classroom observations as part of the annual evaluation of the project.en-USMathSecondary mathTechnical Report