When traversing the land of Skyrim, I use my detect life to mainly ensure that if there's danger, I can strike first. This comes with a price. It feels like my magika is contained in a bottle and to detect life, I have to pour it out on the ground. All of it. I know that my alteration xp will only go up if I am detecting a life, but does it go up based on how many lives are being detected?
Also, what about friend vs foe. ie: Does my xp go up higher for detecting hostile lives (given the chance of them murdering me) rather than in a city?