The National Center for Education Statistics (NCES) is the primary federal entity for collecting and analyzing data related to education.
Why use these data rather than the ARL Index alone?
(1) the data in each are not based on the same survey;
(2) the web interface of the NCES provides more flexibility for analysis than the stagnant ARL data;
(3) the NCES includes institutional data, so you can choose comparison libraries based on university characteristics;
(4) the NCES library data is broader in scope than is the ARL data;
(5) using both lends credibility to each.