lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Robert Muir (Commented) (JIRA)" <>
Subject [jira] [Commented] (LUCENE-3726) Default KuromojiAnalyzer to use search mode
Date Fri, 27 Jan 2012 12:22:44 GMT


Robert Muir commented on LUCENE-3726:

I'm thinking a possibility could be to expose possible decompounds as part of Kuromoji's Token

I like this idea: I think it would give the most flexibility, we would populate some attribute
Token just like we do today, and then actual decomposition can be controlled with a configurable

Long term, this lets the tokenizer stay a tokenizer and prevents it from growing too complex.
> Default KuromojiAnalyzer to use search mode
> -------------------------------------------
>                 Key: LUCENE-3726
>                 URL:
>             Project: Lucene - Java
>          Issue Type: Improvement
>    Affects Versions: 3.6, 4.0
>            Reporter: Robert Muir
> Kuromoji supports an option to segment text in a way more suitable for search,
> by preventing long compound nouns as indexing terms.
> In general 'how you segment' can be important depending on the application 
> (see for some studies on this in chinese)
> The current algorithm punishes the cost based on some parameters (SEARCH_MODE_PENALTY,
> for long runs of kanji.
> Some questions (these can be separate future issues if any useful ideas come out):
> * should these parameters continue to be static-final, or configurable?
> * should POS also play a role in the algorithm (can/should we refine exactly what we
> * is the Tokenizer the best place to do this, or should we do it in a tokenfilter? or
>   with a tokenfilter, one idea would be to also preserve the original indexing term,
overlapping it: e.g. ABCD -> AB, CD, ABCD(posInc=0)
>   from my understanding this tends to help with noun compounds in other languages, because
IDF of the original term boosts 'exact' compound matches.
>   but does a tokenfilter provide the segmenter enough 'context' to do this properly?
> Either way, I think as a start we should turn on what we have by default: its likely
a very easy win.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:!default.jspa
For more information on JIRA, see:


To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message