 Participants were leading scientists from a wide range of fields.Casual recollections of several participants as well as published comments in the Transactions volumes stress the communicative difficulties in the beginning of each set of conferences, giving way to the gradual establishment of a common language powerful enough to communicate the intricacies of the various fields of expertise present.Participants were deliberately chosen for their willingness to engage in interdisciplinary conversations, or for having formal training in multiple disciplines, and many brought relevant past experiences (gained either from earlier Macy conferences or other venues).