About the Principal Investigators

Deborah Schifter, Virginia Bastable, and Susan Jo Russell have been collaborating on professional development for math teachers, mathematics curriculum, and mathematics teaching research projects since 1993. In addition to Developing Mathematical Ideas, they have co-authored Connecting Arithmetic to Algebra and the forthcoming book, Mathematical Argument in the Elementary Classroom.

	Deborah Schifter is a principal research scientist at the Education Development Center in Waltham, Massachusetts. Not only has she taught elementary, secondary, and college-level mathematics but she has also worked as an applied mathematician. Since 1985 she has been a mathematics teacher educator and education researcher. Schifter’s publishing credits include the authored book Reconstructing Mathematics Education:  Stories of Teachers Meeting the Challenge of Reform and the editing of a two-volume anthology of teachers' writing, What's Happening in Math Class? She was also a writer for The Mathematical Education of Teachers as well as for the second and third editions of the kindergarten–grade 5 curriculum Investigations in Number, Data, and Space.
	Susan Jo Russell is a principal research scientist at the Education Research Collaborative at TERC, in Cambridge, Massachusetts. She began her career as an elementary classroom teacher of kindergarten–grade 3 and a coach for teachers in kindergarten–grade 5. For more than thirty years, she has been an educational researcher and teacher educator, focusing on how students and teachers learn about data analysis, number and operations, and early algebra. Russell co-directed the first and second editions of the National Science Foundation–funded elementary curriculum Investigations in Number, Data, and Space, and is developing materials for teachers about mathematics practices for the third edition.
	Virginia Bastable is the associate director of Mathematics Leadership Programs (MLP) at Mount Holyoke College in South Hadley, Massachusetts. Before turning to a career in professional development and research in mathematics education, she was a middle and secondary school mathematics teacher. At MLP, Bastable facilitates course work for teachers, teacher leaders, and math coaches. She is a co-author of the second edition of the kindergarten–grade 5 curriculum Investigations in Number, Data, and Space, and is contributing to the development of the third edition.