Northern Light supports natural language searching. You can simply type a question into the search box.. Northern Light supports full Boolean capability (AND, OR, NOT), including parenthetical expressions, in all search forms. There is no limit to the level of nesting which you can use in a query.  You can use AND (or preface a word with a +) to indicate words that Must appear in the document you are searching for.  You can use NOT (or preface a word with a -) to indicate that a word must not appear in the document.  You can use OR to indicate words that can appear in the document you are searching for, but are not required.  Northern Light automatically searches  most common plural and singular forms of words in addition to a search word (a search on cat will also return results containing the word cats, and a search on cats will return results containing the word cat.)

Examples:

What is the capital of California?
golf courses Washington
   (instead of Golf)
"Jack AND Jill"
    will return documents regarding the phrase "Jack AND Jill"
War AND Peace
    will return documents that contain the word Jack and the word Jill.
War +Peace
Mustang NOT horse
Mustang -horse
Horse OR Pony

Northern Light also supports two wildcards in queries.  The * (asterisk) can be used to replace multiple characters.  The % (percent) symbol is used to replace only one character.  The only limitation is that you must have at least four non-wildcard characters in a word before you introduce a wildcard.  Please note that

Examples:

chemi* will find results containing words that begin with 'chemi' (e.g. chemical, chemistry, chemist)
psych*ist will find all results which contain words that begin and end with 'psych' and 'ist' (e.g. psychologist, psychiatrist)
gene%logy will return documents containing words beginning with 'gene' and ending with 'logy,' separated by a single letter (e.g. genealogy and geneology). Useful for commonly misspelled words

You can also use multiple truncation symbols within a single word.  Expanded words found by using truncation symbols will not affect the relevancy ranking of those documents, so you may want to use additional related terms in your query to ensure that your results are accurate and meaningful.