Introduction: the context for critical issues in early childhood professional development / Ivelisse Martinez-Beck and Martha Zaslow -- Toward better definition and measurement of early childhood professional development / Stephanie M. Curenton -- Defining and measuring professional development in early childhood research / Kelly L. Maxwell, Cathie C. Feild, and Richard M. Clifford -- Estimating the size and characteristics of the United States early care and education workforce / Richard N. Brandon and Ivelisse Martinez-Beck -- Quality and qualifications: links between professional development and quality in early care and education settings / Kathryn Tout, Martha Zaslow, and Daniel Berry -- Studying the culture of quality early education and care: a cumulative approach to measuring characteristics of the worfkforce and relations to quality in four Midwestern states / Helen Raikes, Julia Torquati, Susan Hegland, H. Abigail Raikes, Jacqueline Scott, Lana Messner, Carla Peterson, Kathy Thornburg, Becky Houf, and Sandra Scott -- Completing the model: connecting early child care worker professional development with child outcomes / Kyle L. Snow -- Toward effective support for language and literacy through professional development / David K. Dickinson and Joanne P. Brady -- Helping early childhood educators to teach mathematics / Herbert P. Ginsburg, Rochelle Goldberg Kaplan, Joanna Cannon, Maria I. Cordero, Janet G. Eisenband, Michelle Galanter, and Melissa Morgenlander -- Self-regulation as a key to school readiness: how early childhood teachers can promote this critical competency / Elena Bodrova and Deborah J. Leong -- Designing models for professional development at the local, state, and national levels / Naomi Karp -- Standardized observation and professional development: a focus on individualized implementation and practices / Robert C. Pianta -- Alignment in educator preparation for early and beginning literacy instruction: a state-level case example / Kathleen Roskos, Catherine A. Rosemary, and M. Heidi Varner -- NAEYC's standards for early childhood professional preparation: getting from here to there / Marilou Hyson and Heather Biggar -- Economic perspectives on early care and education / V. Jeffrey Evans -- A framework for cost-benefit analysis of professional development in early care and education / W. Steven Barnett and Pamela J. Kelley -- Early childhood professional development programs: accounting for spillover effects and market intervention / H. Elizabeth Peters and Barbara Bristow -- A course for improved professional development across various programs and policies / Martha Zaslow -- Creating and sustaining a high-quality workforce in child care, early intervention, and school readiness programs / Sharon Landesman Ramey and Craig T. Ramey -- Improving connections between professional development research and early childhood policies / Melissa Welch-Ross, Anne Wolf, Martha Moorehouse, and Colleen Rathgeb.