I have queries that look like this:

SELECT DISTINCT id, MATCH(column) AGAINST('%s' IN BOOLEAN MODE) AS score
 FROM table
  WHERE 
  MATCH(column) AGAINST ('%s' IN BOOLEAN MODE)
 ORDER BY score DESC

I don't actually USE "score" in the results, though, it's just there for sorting.

But in retrospect, I'm not really sure why I'm using "IN BOOLEAN MODE". I realize that I could do this and get the same results (it sorts by "relevance" automatically):

SELECT DISTINCT id
 FROM table
  WHERE 
  MATCH(column) AGAINST ('%s' IN NATURAL LANGUAGE MODE)

I've read the docs on both, but I'm not really sure what the difference is between the two modes:

Natural Language Mode:
[dev.mysql.com...]

Boolean Mode:
[dev.mysql.com...]

I don't use InnoDB.

I know that the user can use + and - in Boolean Mode, as well as other operators, but I can't expect users to know that. And I'm not really sure that they would make it past mysqli_real_escape_string(), anyway. I guess that I could set up a form with the user to select options, and then plug them in myself?

I have no clue what the "50% threshold" is that it mentions, either.

What do you guys and gals think, which is better for a simple search form that users submit from PHP?