Twenty-two young children, maintained on a diet that excluded certain foods, were challenged intermittently with a blend of seven artificial colors in a double-blind trial. Parents' observations provided the criteria of response. One child that responded mildly to the challenge and one that responded dramatically were detected. The latter, a 34-month-old female, showed a significant increase in aversive behaviors. These results further confirm previous controlled studies.

The specification of units is an important issue in any family interaction research in which samples of communication are coded. This paper first reviews the methods investigators have used to cope with this problem and then outlines a new Interaction Unitizing Scheme for preparing type‐scripts using the “speech” as the interaction unit. Subsequently, coding can be done directly from these unitized transcripts, or they can be used to define units when coding from audio or videotape. Reliability methods are outlined, and data are presented indicating that the unitizing scheme has high inter‐coder reliability.