Jeremy Miciak and his colleague, Jack Fletcher, from the University of Houston Texas Center for Learning Disabilities argue that cognitive testing is not necessary for the identification of SLD through an SLD Manual with the TEA logo on it.  He argues that cognitive testing through any of the 5 PSW methods are not reliable or valid, and that cognitive testing does not do a good job of effectively guiding instruction.  As an alternative, he poses a TCLD or Hybrid Model that incorporates but formal achievement assessments and detailed progress monitoring data.