Again, not arguing the result in this case, but here's a quotation
from the SRD:
Quote:
To make a skill check, roll 1d20 and add your character’s skill modifier for that skill. The skill modifier incorporates the character’s ranks in that skill and the ability modifier for that skill’s key ability, plus any other miscellaneous modifiers that may apply, including racial bonuses and armor check penalties. The higher the result, the better. Unlike with attack rolls and saving throws, a natural roll of 20 on the d20 is not an automatic success, and a natural roll of 1 is not an automatic failure.
You can, of course, make a house rule to the contrary. IMO, the lack of critical successes and failures for skills makes sense. It prevents things like a first level rogue trying to activate a high-level item until it works for him (critical success), or a 20th level ranger strangely unable to spot the glowing neon, 2' deep tracks in front of him (critical failure).