The Private School Universe Survey (PSS) is conducted by the National Center for Education Statistics (NCES) on behalf of the U.S. Department of Education in order to collect basic information on American private elementary and secondary schools. PSS grew out of a proposal in 1988 to develop a private school data collection that would improve on the sporadic collection of private school data dating back to 1890 and improve on commercially available private school sampling frames. PSS was first collected in the 1989–90 school year, with data collections every 2 years since.