They are not the same.
Improved Parry: The character gains a +4 bonus to his opposed attack roll when using the parry skill.
I.e Not very good as parry only give you the change to parry 3 attacks no matter how many attaks you have.
Requires a INT of 13+
Expertise:
You get a +5 to your AC but a -5 to your attack roll.
Good for creatures that can hit you hard but arn't hard to hit.
Requires a INT of 13+
Most fighters only use expertise to get to the Weapon Master class as it is a skill that is required for this class.
__________________
|