I believe that I read or heard somewhere that changing the difficulty does not change the amount of experience gained. If correct, how does this exactly apply to skills? I would think that a normal enemy might have more hp and armor than an easy enemy therefor take more hits from a 1h sword or use more magic to kill, thus resulting in more experience gained for the skill being focused on. Is skill experience based on damage done with a sword or hits landed? Meaning do I have to do 100 HP damage for level 2 one handed sword or swing and hit my sword 100 times? I played Morrowind, but I cannot recall what is correct. If anyone knows an answer based on previous TES games or has heard for this game in particular, please let me know.
The way that the previous elderscrolls games have contributed to leveling up is on the amount of times your skill is successfully used (eg each time your sword hits is 1 point towards the associated skill leveling up, or every successful cast of a spell is a point towards the associated magicka school the spell is from, or every hit you take is a point towards the armor skill you are wearing.)
Thats the simple version, as lower skills may have 2-5 points for each successful hit/cast to enable them to level faster, but this usually slows down as the skills get higher.
The dificulty slider in previous games just really gave enemies higher Health and Damage so they took more hits to kill and did more damage to you.
The only difference that I have heard in Skyrim is the higher the skill the quicker it levels so it looks like the lower skills have only 1 point towards the skill leveling when used, where as higher skills have more points towards the leveling when used so they level faster