Query

Single term query

The query specifies only one term for retrieving all documents which contain the term. e.g.,

japan

AND query

The query specifies two or more terms for retrieving all documents which contain both terms. You can insert the and operator between the terms. e.g.,

Japan and tokyo

You can ommit the and operator. Terms which is separated by one ore more spaces is assumed to be AND query.

OR query

The query specifies two or more terms for retrieving all documents which contain either term. You can insert the or operator between the terms. e.g.,

Japan or tokyo

NOT query

The query specifies two or more terms for retrieving all documents which contain a first term but does't contain the following terms. You can insert the not operator between the terms to do NOT query. e.g.,

japan not tokyo

Grouping

You can group queries by surrounding them by parentheses. The parentheses should be separated by one or more spaces. e.g.,

( japan or tokyo ) and osaka not kyoto

Phrase searching

You can search for a phrase which consists of two or more terms by surrounding them with double quotes like "..." or with braces like {...}. In our service, precision of phrase searching is not 100 %, so it causes wrong results occasionally. e.g.,

{Bill Clinton}

Substring matching

The are three types of substring matching searching.

Prefix matching

inter* (terms which begin with inter)

Inside matching

*text* (terms which contain text)

Suffix matching

*net (terms which terminated with net)

Notes

• In any queries, our service ignores case distinctions of alphabet characters. In other words, it does case-insensitive pattern matching in any time.
• Japanese phrases are forced to be segmented into morphemes automatically and are handled them as phrase searching. This processing causes invalid segmentation occasionally.
• Alphabet, numbers or a part of symbols (duplicated in ASCII) characters which defined in JIS X 0208 (Japanese Industrial Standards) are handled as ASCII characters.
• Our service can handle a term which contains symbols like TCP/IP. Since this handling isn't complete, you can describe TCP and IP instead of TCP/IP, but it may cause noisy results.
• Substring matching takes more time than other methods.
• If you want to use and, or or not simply as terms, you can surround them respectively with double quotes like "..." or braces like {...}.