This is Perl module Lingua::JA::TFIDF. INSTALLATION Lingua::JA::TFIDF installation is straightforward. If your CPAN shell is set up, you should just be able to do % cpan Lingua::JA::TFIDF Download it, unpack it, then build it as per the usual: % perl Makefile.PL % make && make test Then install it: % make install DOCUMENTATION Lingua::JA::TFIDF documentation is available as in POD. So you can do: % perldoc Lingua::JA::TFIDF to read the documentation online with your favorite pager. Takeshi Miki