About Us

Principal Investigators (P.I.’s) 

Sascha Longstreth, Ph.D.

[email protected]

Sascha Longstreth Dr. Longstreth is an Associate Professor in the Department of Child and Family Development at San Diego State University. She began her career as a preschool teacher and has extensive experience in a variety of educational settings.  She has worked with the YMCA, Head Start, and Polinsky Children’s Center to train early care and education teachers on topics related to infant and early childhood mental health. Dr. Longstreth’s research is closely connected to her teaching practice, and she is currently investigating the quality of discipline policies in NAEYC-accredited programs across the nation.  She has also investigated teacher’s perceptions of continuity of care and is deeply committed to the exploration of practices that support children’s developing social emotional competence.

Sarah Garrity, Ed.D.

 Sarah GarrityDr. Garrity is an Associate Professor in the Department of Child and Family Development at San Diego State University and was a practitioner in the field of early care and education for almost twenty years as a Head Start teacher, administrator, and literacy coach for the Early Reading First program. At SDSU, she teaches courses on best practices of infant toddler care and language and literacy for a diverse society. Dr. Garrity's research involves the exploration of how best practices are implemented in the field, with a focus on continuity of care, positive behavioral support, and programs serving culturally and linguistically diverse students. Her research aims to increase understanding of the research to practice gap by exploring the complexities of educational settings. In addition to her work on the TAGPEC, she is also investigating Head Start teacher beliefs on discipline and teaching practices.

Graduate Students

We are currently working with several graduate students to explore how evidence-based behavior guidance policies can be used to improve social and academic outcomes for young children.

If you are a student at SDSU and are interested in joining our lab, or if you are a graduate student at another university and would like to use the TAGPEC as a research tool, please contact us.


TAGPEC checklist

Our work is guided by the 5 assumptions of our Humanistic Approach to Teaching and Behavior Guidance


1. The role of the adults is to teach children appropriate social emotional skills

2.  Relationships guide and regulate behaviors

3. Behavior is communication

4. Each child is a unique individual

5. Implicit bias affects decision making