their core results were remarkably consistent. Across states and grade levels, test scores correlated positively and statistically significantly with staff and collection size; library staff activities related to learning and teaching, information access and delivery, and program administration; and the availability of networked computers, both in the library and elsewhere in the school, that provide access to library catalogs, licensed databases, and the World Wide Web. The cause-and-effect claim associated with these correlations was strengthened by the reliability of the relationships between key library variables (i.e., staffing levels, collection size, spending) and test scores when other school and community conditions were taken into account.