"> 2. Is the measurement accurate? 0.5% doesn't sound > like a lot to me. 0.5% of a very large number is a very large number" i dont quite go with this - a percentage is the exact instrument to move away from absolutes you can argue that 10% of 1,000,000 is a large number but to the person earning, say, that 1,000,000 it's not actually that big a deal. 10% of 10,000 is a much smaller number but means a lot more to the person earning just that 10,000