I like Gary Wolf's post, and the article he linked to. But I don't like the idea that positive and negative emotions are not two ends of the same scale. Not because I don't think you can be happy and sad at the same time. Rather, I think it assumes an incorrect model of the mind. I believe in Minsky's Society of the Mind theory, that rather than a single entity the mind is a collection of mental agents. Each mental agent itself is a collection of other mental agents, until you get down to the minimal mental agents that twitch your thumb. My interpretation of feeling happy and sad at the same time is that one mental agent is happy while another is sad. In that view, positive and negative are still opposites on the same scale. The conflict only comes when you insist on viewing multiple mental agents as a single entity.
So it seems (to me) that a two dimensional scale with a characterization of the mental agent involved is the best way to measure mood. But then how do you characterize the mental agents? Well, in addition to being a fan of Minsky, I'm a fan of the Buddha. As a Buddhist, when asked to categorize feelings that include suffering, the obvious answer is "desire."
So this week as part of my data collection I started to measure my moods by using a two dimensional value/energy scale, with three values in each dimension, and a tag for each mood specifying the desire involved in the emotion. I will start by trying to track my extreme moods as I have them. As I expand this habit, I may add to that a thrice daily check of my general mood (after getting up, leaving work, and getting ready for bed). I may also add in tracking of common events that I think affect my mood.
At least, that's the plan. But it is clear that quantifying moods is no simple thing, and I intend to adapt my plans based on how the rubber and the road interact.