We have implemented an application-independent collaboration manager, calle
d Collagen, based on the SharedPlan theory of discourse, and used it to bui
ld a software interface agent for a simple air travel application. The soft
ware agent provides intelligent, mixed initiative assistance without requir
ing natural language understanding. A key benefit of the collaboration mana
ger is the automatic construction of an interaction history which is hierar
chically structured according to the user's and agent's goals and intention
s.