Also valuable are trend indicators. These show output (breakfasts delivered, software modules completed, vouchers processed) measured against time (performance this month versus performance over a series of previous months), and also against some standard or expected level. A display of trends forces you to look at the future as you are led to extrapolate almost automatically from the past. This extrapolation gives us another window in our black box. Also, measurement against a standard makes you think through why the results were what they were, and not what the standard said they would be.
