Ellena Sempeles

Ellena Sempeles has expertise in survey methodology, data collection, and statistical analysis. She has worked on large-scale survey research projects for clients including the National Center for Education Statistics (NCES), the National Institutes of Health, and the Centers for Disease Control and Prevention. Her expertise includes designing survey instruments, managing data collection and linkage processes, and conducting both quantitative and qualitative analyses. She is particularly skilled in improving survey protocols and ensuring high data quality through robust methodological practices.

Sempeles has made significant contributions to several NCES surveys, including the National Teacher and Principal Survey, National Household Education Survey, and the National Training, Education, and Workforce Survey. Her work has included leading item quality assessments, optimizing data collection instruments, and addressing nonresponse bias through statistical imputation and linkage methodologies. These efforts have strengthened the reliability and representativeness of data used to inform education policy and program development.

In addition to her work with NCES, Sempeles has played a pivotal role in health-related research projects such as the Project Talent Aging Study. Her efforts have focused on linking longitudinal survey data to external datasets like the National Death Index, revealing critical insights into how early life factors influence cognitive and physical health across the lifespan. She has led data collection initiatives to ensure diverse representation in these studies, including outreach to underrepresented populations.

Sempeles is dedicated to advancing methodologies that enhance the accuracy, utility, and accessibility of large-scale survey data, supporting evidence-based decision-making in education and public health.