******************* Put Figure 1 about here **************
We have identified three key determinants of the net value derived by
a Collaboratory user based on primary goals of usage: level of
information access, interaction richness and
information/interaction cost. The first two elements determine the
gross benefit that accrue to users from spending time on the
Collaboratory, while the third element relates to the users' cost of
acquiring information and engaging in interactions over the
Collaboratory. While we do not imply that our model provides a
complete description of user interactions on a Collaboratory, we
believe it offers a sound rationale for designing a Collaboratory
based on the concept of maximizing user value.