72 WINDOWS: on/off

To observe and record the behavior, in terms of switching on and off, of the lights of a building visible from the window.

For 3 hours, every 15 minutes:

1. Observe each of the windows in the building.

2. Make a mark on the grid if the light of the observed window is on, otherwise observe the next window.

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

•