One set of universe surveys, the Common Core of Data (CCD), is featured in this issue. The CCD is made up of six separate annual surveys that are sent to state education departments, where data are compiled from state administrative records for the 90,900 public elementary and secondary schools and the 14,500 regular school districts with students. The CCD surveys include public school fiscal and nonfiscal data aggregated at the state and at the school district levels, as well as school-level data. These surveys, plus the biennial Private School Survey (PSS) of data from 27,000 private schools, comprise the NCES universe surveys at the elementary and secondary school levels.

At the postsecondary level, the Integrated Postsecondary Education Data System (IPEDS) includes all 9,600 institutions and educational organizations that provide postsecondary education. As of fall 2000, IPEDS will consist of two annual surveys-a fall and a spring data collection-which will include data on institutional characteristics, completions, enrollments, graduation rates, finance, and the state of residence of first-time students. IPEDS data can be used to describe trends in postsecondary education at the institutional, state, and national levels. For example, researchers can use IPEDS data to analyze data on enrollments and completions of students at different levels by sex and race/ethnicity and by characteristics of postsecondary institutions such as tuition and room and board charges and institutional revenue and expenditure patterns. IPEDS data collection will be entirely Web based beginning in fall 2000.

The Library Statistics Program includes one biennial and two annual universe surveys. The Public Libraries Survey is an annual survey of 8,900 public libraries, with data ranging from usage, size of collection, staffing patterns, and finances to electronic access. The annual State Library Agencies Survey provides descriptive data on services related to library development and the administration of federal funds for libraries. The Academic Library Survey is a biennial universe survey that collects data from the 3,800 degree-granting postsecondary institutions to provide national and state overviews of academic libraries on topics similar to those reported for public libraries.

Although the three cooperatives operate separately, they share a number of common features:

• Membership: Each cooperative includes members from federal, state, and local education agencies with responsibilities for collecting and reporting education data. The members include data providers, data users, government employees, and representatives of public and private institutions and associations.
• Utility: The mission statement of each cooperative stresses the goal of meeting policymakers' needs for data that support policy development, implementation, and evaluation.
• Comparability: In order to be useful, the data must be of high quality and must be comparable across reporting units; thus, quality and comparability are also key-stones of each cooperative's mission statement.
• Coordination: To meet these goals, each cooperative recognizes the need to work together to develop and adopt data standards, including common definitions, standards for the electronic exchange of data, guidelines to promote data collection, and data sharing processes that appropriately preserve confidentiality while permit-ting access and minimizing burden.