Actually, there are classifications existing - if you look at SAR terminology you end up with high angle, low angle, alpine (high elevation mountaineering), mountaineering (what we all think of as hiking with occasional use of nontechnical aids such as crampons or hiking poles) - all classifications require knowledge of how to use navigational aids and do night navigation....
For a grading of ascents check out the Yosemite Decimal System:
* Class 1: Walking with a low chance of injury.
* Class 2: Simple scrambling, with the possibility of occasional use of the hands. Little potential danger is encountered.
* Class 3: Scrambling with increased exposure. A rope can be carried but is usually not required. Falls are not always fatal.
* Class 4: Simple climbing, with exposure. A rope is often used. Natural protection can be easily found. Falls may well be fatal.
* Class 5: Technical free climbing involving rope, belaying, and other protection hardware for safety. Un-roped falls can result in severe injury or death.
Things like talus hopping and scree surfing (glissading, if you are talking about snow fields) fall somewhere in class 2 - class 4 depending on slope.
I am piss poor in some skills, and good at navigation, low angle, mountaineering and "not stepping on the wobbly one."
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