Donna Jackson-Maldonado, Ph.D., is Professor at Department of Languages and Literature (Facultad de Lenguas y Letras) in Universidad Autonoma de Queretaro, Qa de Cedros, Mexico. Dr. Jackson-Maldonado was born in the United States but was brought up in Mexico. She has lived in a bilingual-bicultural environment all of her life. Her initial professional experience was as a speech-language pathologist working with children with language disorders and learning disabilities and deaf children. She also has worked for the Mexican government's special education and communication disorders programs, doing in-service training, writing books and manuals, and developing language assessment instruments. Dr. Jackson-Maldonado received her doctorate in linguistics from El Colegio de Mexico in Mexico City. Her research has been in Spanish and bilingual language development in infants and toddlers. Part of this work was the development of the Mac-Arthur Inventarios del Desarrollo de Habilidades Comunicativas and, with Donna J. Thal, a language and gesture battery for Spanish speakers. Dr. Jackson-Maldonado is currently a full-time professor and researcher at the Universidad Autonoma de Queretaro in Mexico. She directs a project on late-talking Spanish-speaking toddlers. Donna J. Thal, Ph.D., holds a master of science degree in speech pathology and audiology from Brooklyn College and a doctorate in speech and hearing sciences from the Graduate School and University Center of the City University of New York (CUNY). She has been a postdoctoral fellow at the Center for Research in Language at UCSD, an assistant professor at Hofstra University, and an assistant professor at Queens College of CUNY. Dr. Thal is a developmental psycholinguist and a certified and licensed speech-language pathologist who has conducted research in a number of areas, including normal and disordered development of language and cognition, children with focal brain injury, and children with delayed onset of language. She has also carried out studies of language development in Spanish-speaking infants and toddlers. Her most recent work focuses on early identification of risk for clinically significant language impairment and is funded by a grant from the National Institute of Deafness and Other Communicative Disorders (NIDCD), within the National Institutes of Health. Dr. Thal is an editorial consultant for language for the Journal of Speech, Language, and Hearing Research and the American Journal of Speech-Language Pathology. She was the California State nominee for the American Speech-Language-Hearing Foundation Outstanding Clinical Achievement Award in 1996, received the Monty Distinguished Faculty Award from SDSU 1998 and the Albert W. Johnson Research Lecturer Award from SDSU in 1999, and was the Wang Family Excellence Award nominee from SDSU in 2000. She served a 4-year term on the Communicative Disorders Review Committee for the NIDCD from 1998 to 2002. Dr. Thal is a co-author of the MacArthur Communicative Development Inventories. Larry Fenson, Ph.D., is Professor of Psychology at San Diego State University in California. Dr. Fenson has published research on infant attentiveness, early symbolic development, categorization, children's drawing skills, play, and early language development. He received his doctorate in child psychology from the University of Iowa. He served as Assistant Professor at the University of Denver and was a National Institute of Child Health and Human Development postdoctoral fellow with Jerome Kagan at Harvard University. Dr. Fenson is Chair of The CDI Advisory Board. Virginia A. Marchman, Ph.D., is Associate Professor in School of Behavioral and Brain Sciences at the University of Texas at Dallas, Richardson, Texas. Dr. Marchman holds a master of arts degree and a doctorate in developmental psychology from the University of California, Berkeley. She has been an assistant professor at the University of Wisconsin, Madison, and a postdoctoral fellow at the Center for Research in Language at the University of California, San Diego. She has conducted research in several areas of language and cognitive development, language disorders, and early childhood development. Her most recent work focuses on the identification of precursors of language delay and individual differences in lexical and morphological development in monolingual English and bilingual (Spanish and English) speakers. She is on the editorial board of the Journal of Speech, Language, and Hearing Research and was named Distinguished Scholar at the Callier Center for Communication Disorders. Dr. Marchman has worked on the MacArthur Communicative Development Inventories and the MacArthur Inventarios del Desarrollo de Habilidades Comunicativas for the last 15 years. She is author of the CDI Scoring Program. Tyler Newton, M.A., is teacher at Clover Flat Elementary School, Boulevard, California. Tyler Newton received bachelor of arts and master of arts degrees in psychology from San Diego State University. She obtained the California Multiple Subject Teaching Credential from San Diego State University in 2000 and currently teaches second and third grades at Clover Flat Elementary School in Boulevard, California. Her master's thesis involved work on the norming study for the MacArthur Inventarios del Desarrollo de Habilidades Comunicativas. Barbara Conboy, Ph.D., is currently a postdoctoral Research Associate at the Center for Mind, Brain & Learning at the University of Washington. She earned a doctorate in language and communicative disorders at the University of California, San Diego/San Diego State University; a Master of Arts degree in speech-language-hearing at Temple University; and a bachelor of arts in Latin American studies at Smith College. She is certified by the American Speech-Language-Hearing Association as a speech-language pathologist and has worked extensively with bilingual children with language-learning disorders. Her research interests include early bilingualism, experiential factors in language acquisition and brain development, and the early identification and treatment of language impairment in bilingual children. "