The American Library Association and the Association for Library Service to Children (ALSC) offers the Great Web Sites for Kids page. Users will find a large accumulation of recommended sites for kids under different categories such as science, which includes Astronomy and Space, Chemistry and Physics, General Science, Geology, Science Experiments, and Weather and Environment, among others. Other headings include the subjects of Geography and Maps, Biology, and Dinosaurs. Each site contains a brief description, a recommended age level, as well as a direct link . The ALSC uses several criteria in choosing a site, including one that states it "must be meaningful and useful content that educates, informs, or entertains" -- very much like its own site.