A study was conducted in which the infants' behavior was allowed to control stimulus duration. A group of five infants were tested once a week from 3 through 14 weeks of age. A second group of five infants were tested once a week from 8 through 14 weeks of age. A third group of 18 infants were tested once at 3, 8, or 14 weeks of age. Once a stimulus was presented to an infant, it remained on until the two observers had simultaneously recorded no looking behavior for a continuous period of two seconds. Each of six checkerboard stimuli and the grey square were shown twice in two different orders. The longest looking time to a single stimulus recorded in this study was 1073 seconds, or over 17 minutes. Looking durations of over 2 minutes were very common. On several occasions, durations of over 8 minutes were recorded. An analysis of the data was performed. The most important result of this study is the length of time an infant will spend looking at a stimulus in an experimental session. This suggests that it is possible to assess infant attentional patterns in chunks of long behavioral episodes. (CK)