Free-Text Search Help Page

1. Text Search
   To do a simple word search type the text you wish to find into the box after "Search terms:".
   Enclose multiple words in quotes if you want to search on the whole phrase.
   Alternatively, you can leave the text box blank and select from the data sets in the drop down list next to "Search in:" to get all of a certain type of data. For instance selecting "WDC Coral" will provide you a list of all the coral data. Narrow your search even further by using both a search term and a specific dataset.
2. Wildcard Searches
   To perform a single character wildcard search use the "?" symbol in place of a character.
   To perform a multiple character wildcard search use the "*" symbol in place of a set of characters.
   The single character wildcard search looks for terms that match that with the single character replaced. For example, to search for "fire" or "fore" you can use the search:
   
   f?re
   
   Multiple character wildcard searches looks for 0 or more characters. For example, to search for tree, trees or treering, you can use the search:
   
   tree*
   
   You can also use the wildcard searches in the middle of a term.
   
   tr*g
   
   Would find both treering and tracking
   Note: You cannot use a * or ? symbol as the first character of a search.
3. Boolean searches
   Note: All boolean keywords must be entered in all caps.   
   AND
   The AND operator is the default conjunction operator. This means that if there is no Boolean operator between two terms, the AND operator is used. The AND operator matches datasets where both terms exist anywhere in the metadata of a single dataset. The symbol && can be used in place of the word AND.
   
   To search for documents that contain either "Atlantic Ocean" or "Younger Dryas" use the query:
   
   "Atlantic Ocean" AND "Younger Dryas"
   
     OR
   The OR operator finds a matching dataset if either of the terms exist in a dataset. The symbol || can be used in place of the word OR.
   To search for documents that contain either "Atlantic Ocean" or "Caribbean" use the query:
   
   "Atlantic Ocean" OR Caribbean
   
     NOT
   Using NOT(all caps) will find datasets that include one term, but not another. So "tree NOT colorado" will find all datasets with "tree" in them, but exlude all the ones that also have "colorado".
   
   
   
   Grouping into sub queries
   Parentheses can be used to group clauses to form sub queries. To search for either "Atlantic" or "Pacific" and "salinity" use the query:
   
   (Atlantic OR Pacific) AND salinity
   
   This makes sure that salinity must exist and either term Atlantic or Pacific may exist.
4. Fuzzy Searches
   Fuzzy searches find words similar to the search term based on the Levenshtein Distance, or Edit Distance algorithm. To do a fuzzy search use the tilde, "~", symbol at the end of a Single word Term. For example to search for a term similar in spelling to "Anderson" use the fuzzy search:
   
   Anderson~
   
   This search will find names like Andersson and Andersen.
   It will also find special characters in words, so Jurgen~ will find Jürgen
   
   
5. Proximity Searches
   You can find words that are within a specific distance of other words. To do a proximity search use the tilde, "~", symbol at the end of a Phrase followed by a number. For example to search for a "Atlantic" and "salinity" within 10 words of each other in a document use the search:
   
   "Atlantic salinity"~10
6. Escaping Special Characters
   Special characters are part of the query syntax, but they must be escaped to be successfully searched. The current list special characters are
   
   + - && || ! ( ) { } [ ] ^ " ~ * ? : \
   
   To escape these character use the \ before the character.
   For example to search for the phrase "[Target: bulloides]" type in:
   
   \[Target\: bulloides\]
   
   
7. Latitude/Longitude Search
   Latitudes should be entered as values 90 to -90 with no "N" or "S" included to indicate direction. Negative values will indicate Southern hemisphere latitudes.
   Longitudes should be entered as values -180 to 180 with no "E" or "W" included. Negative values will indicate Western hemisphere longitudes.
   
   Blank fields will be assumed to be the maximum allowed value for that direction, so leaving all fields blank will search the entire globe.
Age Boundary Search
Search uses Calendar Years Before Present where present is defined as 1950. Years more recent than 1950 are indicated by using negative values.
<= is used to find datasets that include data more recent than the value entered.
>= is used to find datasets that include data older than the value entered.

<= -20 cal yr BP will return datasets with data newer than 1970 AD
>= 1500 cal yr BP will return sets with data older than 450 AD)

One search trick is to set the age bounds so that they appear to have no overlap. This will actually find datasets that are completely within the bounds listed.
<= -49 cal yr BP and >= 500 cal yr BP

Will find sets where ALL the data in the set is between 1999 AD and 1450 AD.

Setting the bounds >= -49 cal yr BP and <= 500 cal yr BP will find datasets that include data between 1999 AD and 1450 AD, but it will include datasets with data values outside of these bounds as well. A dataset that runs from 10,000 years BP to Present would be included when it may not have the desired resolution.

http://www.ncdc.noaa.gov/paleo/oaisearch-help.html Downloaded Tuesday, 28-Oct-2008 19:08:16 EDT Last Updated Tuesday, 15-Apr-2008 11:55:14 EDT by paleo@noaa.gov Please see the Paleoclimatology Contact Page or the NCDC Contact Page if you have questions or comments.