LUC's e-Library supports two types of search requests, natural language and Boolean. A natural language search is any sequence of text, like a sentence or a question. After a natural language search, LUC's e-Library sorts retrieved documents by their relevance to your search request.
A Boolean search request consists of a group of words or phrases linked by connectors such as and and or that indicate the relationship between them. Examples:
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Land use and controls |
All words must be present |
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Land use or controls |
Either word or phrase can be present |
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Land use w/5 controls |
Land use must occur within 5 words of controls |
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Land use not w/5 controls |
Land use must not occur within 5 words of controls |
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Land use Only Land use must be present | |
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If you use more than one connector, you should use parentheses to indicate precisely what you want to search for. For example, asphalt and sealcoating or Land use could mean (asphalt and sealcoating) or land use, or it could mean asphalt and (sealcoating or land use). Noise words, such as if and the, are ignored in searches. Search terms may include the following special characters: |
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? |
Matches any single character. Example: appl? matches apply or apple. |
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* |
Matches any number of characters. Example: appl* matches application |
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~ |
Stemming. Example: apply~ matches apply, applies, applied. |
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% |
Fuzzy search. Example: ba%nana matches banana, bananna. |
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# |
Phonic search. Example: #smith matches smith, smythe. |
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& |
Synonym search. Example: fast& matches quick. |
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~~ |
Numeric range. Example: 12~~24 matches 18. |
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: |
Variable term weighting. Example: asphalt:4 w/5 potholes:1 |
Words and Phrases
You do not need to use any special punctuation or commands to search for a phrase. Simply enter the phrase the way it ordinarily appears. You can use a phrase anywhere in a search request. Example:
asphalt w/5 Land use
If a phrase contains a noise word, Lucs.org will skip over the noise word when searching for it. For example, a search for statue of liberty would retrieve any document containing the word statue, any intervening word, and the word liberty.
Punctuation inside of a search word is treated as a space. Thus, can't would be treated as a phrase consisting of two words: can and t. 1843(c)(8)(ii) would become 1843 c 8 ii (four words).
Wildcards (* and ?)
A search word can contain the wildcard characters * and ?. A ? in a word matches any single character, and a * matches any number of characters. The wildcard characters can be in any position in a word. For example:
appl* would match apple, application, etc.
*cipl* would match principle, participle, etc.
appl? would match apply and apple but not apples.
ap*ed would match applied, approved, etc.
Use of the * wildcard character near the beginning of a word will slow searches somewhat.
Natural Language Searching
A natural language search request is any combination of words, phrases, or sentences. After a natural language search, Lucs.org sorts retrieved documents by their relevance to your search request. Weighting of retrieved documents takes into account: the number of documents each word in your search request appears in (the more documents a word appears in, the less useful it is in distinguishing relevant from irrelevant documents); the number of times each word in the request appears in the documents; and the density of hits in each document. Noise words and search connectors like NOT and OR are ignored.
Synonym Searching
Synonym searching finds synonyms of a word in a search request. For example, a search for fast would also find quick. You can enable synonym searching for all words in a request or you can enable synonym searching selectively by adding the & character after certain words in a request. Example: fast& w/5 search.
The effect of a synonym search depends on the type of synonym expansion requested on the search form. Lucs.org can expand synonyms using only user-defined synonym sets, using synonyms from Lucs.org's built-in thesaurus, or using synonyms and related words (such as antonyms, related categories, etc.) from Lucs.org's built-in thesaurus.
Fuzzy Searching
Fuzzy searching will find a word even if it is misspelled. For example, a fuzzy search for apple will find appple. Fuzzy searching can be useful when you are searching text that may contain typographical errors, or for text that has been scanned using optical character recognition (OCR). There are two ways to add fuzziness to searches:
- Enable fuzziness for all of the words in your search request.
- You can also add fuzziness selectively using the % character. The number of % characters you add determines the number of differences Lucs.org will ignore when searching for a word. The position of the % characters determines how many letters at the start of the word have to match exactly. Examples:
- ba%nana Word must begin with ba and have at most one difference between it and banana.
- b%%anana Word must begin with b and have at most two differences between it and banana.
Phonic Searching
Phonic searching looks for a word that sounds like the word you are searching for and begins with the same letter. For example, a phonic search for Smith will also find Smithe and Smythe.
To ask Lucs.org to search for a word phonically, put a # in front of the word in your search request. Examples: #smith, #johnson
Stemming
Stemming extends a search to cover grammatical variations on a word. For example, a search for fish would also find fishing. A search for applied would also find applying, applies, and apply. There are two ways to add stemming to your searches:
Check the Stemming box in the search form to enable stemming for all of the words in your search request. Stemming does not slow searches noticeably and is almost always helpful in making sure you find what you want.
If you want to add stemming selectively, add a ~ at the end of words that you want stemmed in a search. Example: apply~
Variable Term Weighting
When Lucs.org sorts search results after a search, by default all words in a request count equally in counting hits. However, you can change this by specifying the relative weights for each term in your search request, like this:
asphalt:5 and potholes:1
This request would retrieve the same documents as asphalt and potholes but, Lucs.org would weight asphalt five times as heavily as potholes when sorting the results.
In a natural language search, Lucs.org automatically weights terms based on an analysis of their distribution in your documents. If you provide specific term weights in a natural language search, these weights will override the weights Lucs.org would otherwise assign.
AND Connector
Use the AND connector in a search request to connect two expressions, both of which must be found in any document retrieved. For example:
asphalt and Land use would retrieve any document that contained both phrases.
(asphalt or sealcoating) and (potholes w/5 minutes) would retrieve any document that (1) contained either asphalt OR sealcoating, AND (2) contained potholes within 5 words of minutes.
OR Connector
Use the OR connector in a search request to connect two expressions, at least one of which must be found in any document retrieved. For example, mending asphalt or Land use would retrieve any document that contained mending asphalt, Land use, or both.
W/N Connector
Use the W/N connector in a search request to specify that one word or phrase must occur within N words of the other. For example, asphalt w/5 potholes would retrieve any document that contained asphalt within 5 words of potholes. The following are examples of search requests using W/N:
(asphalt or potholes) w/5 sealcoating
(asphalt w/5 sealcoating) w/10 potholes
(asphalt and sealcoating) w/10 potholes
Some types of complex expressions using the W/N connector will produce ambiguous results and should not be used. The following are examples of ambiguous search requests:
(asphalt and sealcoating) w/10 (potholes and minutes)
(asphalt w/10 sealcoating) w/10 (potholes and minutes)
In general, at least one of the two expressions connected by W/N must be a single word or phrase or a group of words and phrases connected by OR. Example:
(asphalt and sealcoating) w/10 (potholes or minutes)
(asphalt and sealcoating) w/10 Land use
Lucs.org uses two built in search words to mark the beginning and end of a file: xfirstword and xlastword. The terms are useful if you want to limit a search to the beginning or end of a file. For example, asphalt w/10 xlastword would search for asphalt within 10 words of the end of a document.
NOT and NOT W/N
Use NOT in front of any search expression to reverse its meaning. This allows you to exclude documents from a search. Example:
asphalt and not potholes
NOT standing alone can be the start of a search request. For example, not potholes would retrieve all documents that did not contain potholes.
If NOT is not the first connector in a request, you need to use either AND or OR with NOT:
asphalt or not potholes
not (asphalt w/5 potholes)
The NOT W/ ("not within") operator allows you to search for a word or phrase not in association with another word or phrase. Example:
asphalt not w/20 potholes
Unlike the W/ operator, NOT W/ is not symmetrical. That is, asphalt not w/20 potholes is not the same as potholes not w/20 asphalt. In the asphalt not w/20 potholes request, Lucs.org searches for asphalt and excludes cases where asphalt is too close to potholes. In the potholes not w/20 asphalt request, Lucs.org searches for potholes and excludes cases where potholes is too close to asphalt.
Numeric Range Searching
A numeric range search is a search for any numbers that fall within a range. To add a numeric range component to a search request, enter the upper and lower bounds of the search separated by ~~ like this:
asphalt w/5 12~~17
This request would find any document containing asphalt within 5 words of a number between 12 and 17.
Numeric range searches only work with positive integers. A numeric range search includes the upper and lower bounds (so 12 and 17 would be retrieved in the above example).
For purposes of numeric range searching, decimal points and commas are treated as spaces and minus signs are ignored. For example, -123,456.78 would be interpreted as: 123 456 78 (three numbers). Using alphabet customization, the interpretation of punctuation characters can be changed. For example, if you change the comma and period from space to ignore, then 123,456.78 would be interpreted as 12345678.