Information systems with an intelligent or knowledge component are now prevalent and include knowledge-based systems, intelligent agents, and knowledge management systems. These systems are capable of explain their reasoning or justify their behavior. Empirical studies, mainly with knowledge-based systems, are reviewed and linked to a theoretical and practical base. The present paper has two main objectives: a) to present a negotiation strategy that allows the interaction between an intelligent agent and a human consumer. This kind of negotiation is adapted to the Latin American market and idiosyncrasy where an appropriate tool to perform automated negotiations over Web does not exist. b) To include animations in order to show an agent that represents an actual person. This incorporation aims to reduce the impact and gap created by the new technology. The agent presented can find an optimal path to achieve its goal using its mental states and libraries designed for the business roles.