[Powertop] questions concerning powertop --calibrate output

Hi,

When running 'sudo powertop --calibrate' I observe that it is 
calibrating idle, disk usage, backlight, CPU, USB devices and so forth. 
  At the end of the calibration process powertop dumps out a table 
headed "Parameter state". Couple of questions about this table:

1. What does the "Value" column refer to, and what units are they being 
measured in? I'm trying to figure out the significance of these values.

I believe that the rows are sorted on name order and the following 
number in parentheses refers to the internal index number of this 
device. At first I thought this number had some deeper significance.

2. At the end of the table there are values annotated as "Score", 
"Guess" and "Actual".  Again, what are these referring to?

3. At the end of the calibration process has powertop tuned the system 
to a more "optimal" power configuration?

Thanks for any insight,

Colin