3.1.4 Advanced Search
The EarthRef Digital Archive Advanced Search form allows you to combine various search terms and fields to generate the most specific results. It also allows you to modify your search by using the boolean keywords OR, AND or AND NOT between search terms. Separating your search terms with spaces or colons is the equivalent of using the OR keyword.
The search form gives two fields into which you may type your search terms, and each field is related to a pulldown list. The pulldown list allows you to indicate in which field you would like to use your search terms, including Keyword, Parameter, Material, Latitude Range, Longitude Range, Continent, Country, Region, Age Range (in Ma), and Time Scale. Each of the allowed ranges may be specified by using spaces between the terms, e.g., 0 4550 to specify the Age Range 0 to 4550 Ma.
You may use one, both, or neither search term fields, depending upon the type of search you wish to perform. If you use both fields, you must select a boolean modifier AND, OR, or AND NOT from the list that appears between the fields. This will affect how the search query is built, and will affect the number of results that appear in your search. AND means that the terms in both fields must appear in the search results, while OR indicates that one or the other (or both) may appear. AND NOT means that the first terms must be in the results, but the second terms must not be. If both search term fields are left blank, the Project Name and/or Expert Level fields must be used in your search.
The Data Type list allows you to search for ERDA contributions that have files of a certain type associated with them. Indicating a certain data type in your search will result in only those contributions containing the selected data type.
Expert Level indicates to which audience a particular contribution is directed. They range from Preschool and Elementary School to State-of-the-Art Science. You may choose to search for contributions only within a specified level by selecting "This Level Only", or to broaden your search results by selecting "This Level and Lower" or "This Level and Higher". By selecting one of the two latter options, your search will include contributions in the level specified in the Expert Level list, plus any level that appears above it or below it, as specified in the Lower or Higher modifier.
The Project Name list allows you to specify that you are searching for contributions that relate to a specific EarthRef Project. Contributions are grouped into projects to allow users to locate them more easily. You may specify a general project name, such as "Earth Science Software", or a more specific name, such as "EarthRef.org Data Population Tools".