How can I get information about an enemy's elemental weakness?

How can I determine elemental weaknesses (the armamentalist abilities can add elemental properties to party members during battle) for enemies? I know thieves have an ability to gain more information on enemies, but it does not appear to display elemental weaknesses (if they exist).

Solution 1:

Against most normal monsters, weaknesses rarely come into play as you can beat them down quite fast. Weaknesses mostly come into play against bosses, and the only place I know of to get weaknesses for bosses is the DQ9 wiki: http://dragonquest.wikia.com/

Solution 2:

The thief's Eye For Trouble ability adds additional information to the Defeated Monster List, which sometimes tells elemental strengths and weaknesses. If there, it's somewhere in the text description of the monster, and not called out alongside experience or gold per monster.