MERLIN TimeTraks ® provide a picture of three time-sensitive functions: onset, intensity and duration. Onset means the point of appearance of uncharacteristic activity or heightened eventfulness (within 60-120 days of real time.) It represents the time coordinates in a chronograph, where there is a pronounced restructuring in the character of the TimeTrak ®or where a clearly defined episode begins. Intensity means the value of the TimeTrak ® at a particular time-interval, relative to the average level of activity present in that entire TimeTrak ® Duration means the extent of a given episode. How long does the TimeTrak ® demonstrate significant activity? How long will a given episode (or portion of an episode) last?