In this paper, I address some of the unique challenges of studies of learning in museums through a microanalytic case study of meaning-making among a group of youth and a curator. Through an examination of youths' forms of participation in one exhibit, I illustrate local meaning making achieved through multiple modalities--by doing, talking, and the manipulation of the exhibit. In turn, I show how multiple on-going dialogues come to interact and constitute talk and action at the science exhibit underlining the idiosyncratic nature of meaning-making. While the dialogue examined in this paper may be considered as a rather unremarkable event in terms of learning, it underlines that the study of meaning-making entails a focus on more than mere conversations in situ in that verbal and nonverbal interactions need to be considered simultaneously. Furthermore, the analysis suggests that museums may be best seen as one among many resources for science literacy development whose impact can only be understood through an assessment of learning trajectories over time and across space. Suggestions are made for museum design and future studies of learning in consideration of the issues raised.