We propose a method for using ethnographic field data to substantiate agent-based models for socially-oriented systems. We investigate in-situ use of domestic technologies created to encourage fun engagement between grandparents and grandchildren separated by distance. The field data added an understanding of what 'intergenerational fun' means when 'filled' with concrete activities. Our contribution is twofold. First, we extend the understanding of agent-oriented concepts by applying them to household interactions. Second, we establish a new method for informing quality goals with field data to enable development of novel applications in the domestic domain.