Here is an entry from my morgue book. I sat at Winstead's on Friday and drew the check-out station. 2 minutes with a drawing every 30 seconds.
Incremental Drawing with Model 9/13/10
Here we sat out on the lawn and drew our wonderful model doing 2 minute poses. She progressed across the '9' sculpture over 12 steps.
I could see how this is helpful when each pose is keyed onto it's own page but when it's a jumble like this all I get out of it is the path the head and shoulders take throughout the action. Although there is something magical about that in it's own right.