Interactive Public Displays (IPD) enable new ways of interaction as well as communication channels, extending online communities into physical places and supporting a culture of participation. While educational environments have seen how new digital technologies can enhance learning activities beyond the traditional classroom context, the use of IPDs is still an area insufficiently explored. This paper proposes a set of design goals for the implementation and deployment of engaging interactive public display applications in educational settings. Based on findings from a series of design workshops and two deployment studies in authentic settings, seven design goals were identified and defined. The design goals provide clear guidelines for the design of IPDs for schools by making design teams and stakeholders focus on factors fostering user adoption, social interactions and collaboration. The design goals also opened up paths for further explorations regarding display awareness, level of commitment in interactions, the displays' integration into structured activities, and display management at the educational institutions.