Spellcraft / Knowledge(Arcana) - Does it work on Spell-like abilities?

[Ross Byers]

Is it possible to identify a spell-like ability as it is being used/cast via a Spellcraft check? How about identifying a "spell effect" left by a spell-like ability with Knowledge(Arcana)?

This is not spelled out in the rules, which is otherwise clear that Spell-like abilities, while resembling spells in many ways, are not, in fact, spells.