Involvement with the new HSLS:09 offers the National Science Foundation (NSF) the opportunity to fulfill one of its primary goals – that of providing researchers and States the means and opportunity to explore adolescents’ interests, motivation, activities, and background in science, technology, engineering, and mathematics (STEM) content areas. The state representative samples that NSF is sponsoring not only will support comparative analyses between States and the Nation but also will combine data from State administrative databases (e.g., students’ test scores, math and science courses, student records prior to entering 9th grade) with rich, longitudinal survey data for sampled students in those States.