The National Science Digital Library (NSDL) was created in 2000 by the US National Science Foundation as a freely available online library of links to science, technology, engineering and mathematics (STEM) information resources. NSDL strives to provide a centralized point of access to quality resources aggregated from a variety of other digital libraries, projects funded by the National Science Foundation, and NSDL reviewed web sites. The NSDL community comprises a broad spectrum of contributors including museums, federal agencies, research laboratories, libraries, professional societies and commercial content providers. The daily management of the site is maintained through the collaborative efforts of the University Corporation for Atmospheric Research, Cornell University, and Columbia University.
NSDL offers access to resources and tools that support teaching and learning for pre‐K‐16, post‐secondary, graduate study, and professional education. Resources include images, video, audio, animation, software, datasets, news reports, online community discussions, and text documents such as journal articles and lesson plans. Items submitted directly to the NSDL are reviewed by the NSDL Collections Director. Resources included by NSDL partner libraries have already undergone a review process through peer review boards or committees. Other resources have been developed as a result of National Science Foundation or other federal agency grants whose competitive selection processes include expert review panels. NSDL also provides an Ask‐NSDL service, where users can send questions, which are answered, from a pool of over 300 scientists and technical professionals.
There are a variety of ways to navigate through the site's resources. Users can browse alphabetically by title or by collection name. The browse‐by‐topic feature allows searchers to follow a subject path under the general categories of Education, Health, Mathematics, Science, Social Studies, and Technology. These categories can be browsed textually or by using an interactive Java‐based image map. Also available is a links page targeted to specific audiences including K‐12 teachers, librarians, university faculty, first‐time users, and the NSDL community.
NSDL is searchable. The homepage features a text box to search the entire library. This method will work best for most users. Keyword searches can be limited by certain criteria. However, using these more advanced search mechanisms requires knowledge of the limitations of the system. For example, users can narrow their search results by grade level and/or by format, but not all resource metadata have the format and grade level information available, so limiting by these criteria may exclude some relevant resources from the results list. Searches can also be limited to specific NSDL collections. An easy to locate Search Tips link brings the user to a concise, helpful screen offering instructions on advanced search techniques and considerations.
While most of the resources accessed through NSDL are free, some information providers require a fee to retrieve specific information. Because NSDL aggregates resources from a wide variety of content providers, each provider has its own copyright policies. NSDL claims that most of the providers anticipate “fair use” for educational purposes, but caution should be exercised before reusing any material without the authors' permission.
The National Science Digital Library provides links to very useful, practical material for a wide audience of educators and learners. The screens are well organized and visually appealing. The browse feature allows for easy navigation. Searching the site by keyword is an effective way to navigate through the hundreds of resources available. But since the NSDL adds links on a weekly basis, the inconsistencies of some of the search features (such as setting limits to grade level and format) need to be resolved as the library grows.
