I'd just like to point out that daggers can be and always have been used as slashing weapons, and not just to go all Stabbity McStabface. There are several perfectly valid reasons to slash instead of stab with a dagger or short blade, including but not limited to requiring less accuracy, for parrying attacks, and for causing nice, wide, painful gashes to the rich-in-nerve-ending outer layers of the skin.
Yea I really hate this misconception that you need a long weapon to slash people with. No, what you need is a blade terminating in a point, just like you do for stabbing.
You can slash somebody with the tip of a pencil if you want to. But, the depth of the cut is limited by the length of the cutting edge, and the fact that there were no stabbing attacks with the dagger in Oblivion was a definite over sight.