This skill feat states: Prerequisites: expert in Arcana, Nature, Occultism, or expert in Religion. You rarely misidentify an item. When using Arcana, Nature, Occultism, or Religion checks to Identify Magic, if you roll a critical failure, you get a failure instead.
It seems like RAI you would need to be expert in the applicable knowledge skill in order to able to benefit from Assured Identification, but looking at the language of some of the other skill feats, it is not so clear to me.
For example, the Quick Recognition skill feat states: Prerequisites: Recognize Spell; master in Arcana, Nature, Occultism, or Religion. You Recognize Spells swiftly. Once per round, you can Recognize a Spell using a skill in which you’re a master as a free action.
That feat specifies you need to be master in any skill you intend to use for this feat. Assured identify has no such language of "in which you are expert." So does this mean you can use it for trained-only skills?
As an example, a character is expert in Arcana, meeting the feat's prerequisite, so he takes that skill feat. He is also trained in Nature and wants to benefit from Assured Identification when making a Nature check to identify a magic item with the primal trait. Does this work? How would you rule it?