search results return by relevancy

Hi there I have some scripts that do a search in a MySQL database table. I want to be able to return rows that match a query, in order of relevancy. For example, say I have a table that has the following data |row_id| data |------|------------------------------------- | 1 | cat | 2 | cat cat | 3 | cat cat cat | 4 | cat cat | 5 | cat cat cat cat cat cat cat | 6 | cat | 7 | cat cat cat cat | 8 | cat cat cat cat cat I want to do a search that would return row_id 5 first, then row_id 8, then row_id 7, then 3, etc. So I want to order the return by relevancy. What should the sql query look like? select * from table where data like '%cat%' order by ????? thanks -jen