Observations in a neighborhood day care center revealed that teachers, when they handed out a "paint shirt" without fastening it, set up a situation in which children helped one another. With modifications, this naturally occurring situation was used in order to increase the incidence of peer helping behavior so that it could be studied naturalistically. The modifications structuring the setting were as follows: a "superperson suit" similar to a paint shirt (a blue smock with a red star on the chest, fastened with a large button and buttonhole at the back of the neck) was introduced to the children as a new toy. The opportunity to wear the superperson suit was determined by a random drawing of children's names; each time a name was drawn, the teacher would set a timer, place the suit on the child's front with the straps over the shoulders, and say quietly that she was too busy to button it. Videotaping began at this point. The child was allowed to enter free play and either continue to hold the superperson suit on in front, solicit help, or attempt to button the suit by himself or herself. Each child's turn lasted 4 minutes. Videotapes were coded in terms of several categories of donor and recipient behaviors. Additionally, peer ratings and peer nominations were obtained from each child. In 3.13 hours of observation, the structured naturalistic observation method yielded 56 opportunities to help, 32 instances of spontaneously offered help, and 13 instances of recipient prompted help, a substantial increase over the average rate of helping (less than once per hour) reported in unstructured naturalistic settings. (RH)