The design of good user interfaces enhances the acceptance and use of
computers, basically in environments in which their users are not fami
liar with computers. In this paper we concentrate on the design and de
velopment of intelligent interaction systems that provide active conte
xt-sensitive assistance to the user. We seek a compromise solution bet
ween development simplicity and power. To reach this objective, we pro
pose the application of techniques from knowledge engineering to the d
evelopment of active on-line assistance systems, establishing total in
dependence between the knowledge on the interaction domain, the data,
and the control of the communication acts.