Just like with the stock market, watching gains and losses with too fine a granularity will make you tense up and "buy high and sell low."
If you're "going long" on your productivity, collect all the data you like--but have a smoothing function between that input and the resulting metrics. That way, 20 minutes spent to gain 3 hours will look like the slight-dent-and-sharp-rise it is, not a scary better-stop-this plunge.
If you're "going long" on your productivity, collect all the data you like--but have a smoothing function between that input and the resulting metrics. That way, 20 minutes spent to gain 3 hours will look like the slight-dent-and-sharp-rise it is, not a scary better-stop-this plunge.