Traditional observation approaches fall down when the subjects of observation are young Deaf children involved in exploratory design activities, who want to interact with observers, and move rapidly and unpredictably between activities. This paper presents a reflective discussion of our experiences observing design research with young (3-5 years) Deaf children, and recommendations for researchers working with similar groups. Key lessons include: interactions between children and observers can be a source of design data; “passive” observers may not need to know sign language to capture detailed data; and having an appropriate ratio of observers to children is important but may be difficult to balance.