Search Tips

Type one or more words into the search box and click the Search button (or the Enter key).

You must enter words into the search box for the NSDL search to work.

NSDL searches for results using NSDL metadata records (information about the resource) and the text of the resources, when that text is publicly available on the internet. This is similar to searching a catalog in the library, while simultaneously searching the text of the actual books in the library; you are searching on information about the resource, as well as on information from inside the resource.

Search is not case sensitive.

An exact match in capitalization is not required; the following searches will all return the same results:

Want words in a specific order? Use quotation marks.

If you place quotation marks around a phrase or a sequence of words, only resources that include all of the words within the quotes, and in that exact order, will be returned in the search results.

For example, searching on "earth science," enclosed in quotes, means your search results must have the phrase "earth science" in them. Without the quotes, the results may have the words earth and/or science in them, but the words are not required to appear next to each other, or in that particular order.

Combining search terms for better results with boolean logic.

Use boolean logic to broaden or narrow your results by combining search terms using the three Boolean operators AND, OR and NOT.

AND
Use AND to narrow a search by combining terms. AND will return results that contain both search terms.
Example: Frog AND Tree

OR
Use OR to broaden a search to include results that contain either term.
Example: Hurricane OR Typhoon

NOT
Use NOT to narrow a search by excluding terms. NOT returns results that contain only one of the search terms but not the other term.
Example: Bernoulli NOT Physics

Having Problems?

Getting no results, or unexpected results? Try the following:

Check spelling.

Spelling errors can lead to unexpected results or no results. Check your spelling, or try alternate spellings. The search service suggests alternatives for words not found in its dictionary. Click on the suggested spelling offered by the search service for more results.

Choose your words carefully.

Use terms that are as specific as possible to the subject you are interested in, instead of more general terms. For example, use cumulonimbus instead of clouds, or dinosaur instead of large animal. Keep in mind that some words have more than one meaning, or different meanings in different contexts. The word current, for example, can relate to electricity as well as to oceans; using the word electricity along with current, or using the phrase electrical current, will narrow the search. Use words likely to appear in resources devoted to the subject you are interested in, and not likely to appear in resources about other subjects. Or try synonyms; for example, if you are not satisfied with the results from searching on the word weather, try meteorology.

Reset your search options.

Filtering (see below) is a useful way to narrow search results to a manageable number, but if you select too many filtering options, you may filter out all results. If you have selected search filters, you can remove or change them by hovering your mouse over the Reset Search Options button; or you can remove the Grade Level and Format filters individually by unchecking the boxes you have checked.

Using Filters to Narrow Your Search (optional)

Filtering out search results you're unlikely to want, or limiting your search results to resources that share desired characteristics, are useful techniques when your search terms retrieve too many resources. NSDL allows you to do this in several ways.

Filter by audience.

You can confine your search to resources appropriate to different groups of users by selecting an audience tab at the top of the Search Results page. Choosing the General Search tab excludes resources from two large research-paper collections, CiteSeer and ArXiv, that tend to overwhelm search results for the general user. These collections are included in the search when the Specialized Search or Higher Education & Research tabs are chosen.

The K-12 tab excludes resources primarily targeted to higher education and research audiences. (If you are interested in resources for highly advanced high-school students, be aware that the K-12 filter may exclude resources that could be useful.)

The Higher Ed & Research tab excludes resources primarily targeted to K-12 audiences. (If you are interested in resources for college or technical school students in need of basic review, be aware that the Higher Ed & Research filter may exclude resources that could be useful.)

The Specialized Search tab does not exclude any resources by default. More options are available for you to narrow your search by grade level, subject, resource format, and search by Pathway. The search by Pathway option will confine your search results to the Pathway collections that you select. Please see What Are NSDL Pathways? for an explanation of the Pathways.

Filter by collection.

NSDL includes groups of digital resources ("collections") selected or made available by organizations such as the American Museum of Natural History, the National Science Teachers Association, and MIT. Please see the Glossary for an explanation of a Collection. When you search NSDL, you are searching all of these collections simultaneously. On the Search Results page, the logo that appears in the "Found in Collection" column identifies the source of a resource. Hovering your mouse over a collection logo allows you to either exclude a collection unlikely to offer resources in which you are interested, or to search only within a particular collection more tailored to your needs or interests.

Filter by format or grade level. *

Limiting your search results by format (available when you use the K-12, Higher Ed & Research, or Specialized Search tabs) will yield only resources in the formats you have selected. Limiting the results by grade level (available when you use the K-12 tab) will yield only resources that have been identified as being relevant to the grade-level span you have chosen.

Relevant Results from NSDL Pathways

The "Recommended Resources from NSDL Pathway Partners" are resources selected or developed by the NSDL Pathway portals. Please see What Are NSDL Pathways? for an explanation of the Pathways.

* Not all resources in NSDL include format or grade-level information in their metadata, so limiting your search through use of these filters may exclude some relevant resources from the results.