Her research addresses the implementation of RTI and MTSS in urban settings and with English language learners. She engages educators on how to improve systems and instructional practices for students with reading difficulties and those who are English language learners and who have disabilities. Maria B. Serpa, Ed.D. has three decades of experience with educational assessment of ELL students with and without disabilities. Dr. Serpa is professor Emerita at Lesley University. She is co-author of several publications in assessment and (bi)literacy. Her research focuses on nondiscriminatory culturally and linguistically responsive assessment of ELSWDs biliteracy. Paying by check or purchase order?