Geller's research focuses on the development and validation of formative assessment systems in mathematics that provide instructionally relevant information to support students with diverse needs. Her work centers on using technology to provide flexible assessment systems through the integration of accommodations and principles of universal design. She disseminates her research findings through publications and presentations in the areas of mathematics education, measurement and assessment, and special education. Her experience as a science teacher in public high schools and her training as a K–12 administrator inform her research. Scholarship from several Spanish-speaking researchers was used to develop the foundation and blueprint of ISIP Español.