Supervised interaction is concerned with the problem of establishing trust between contracting agents in electronic markets. It is designed to put safeguards in place that ensure that errant behaviour in business transactions is either prevented or sanctioned. Supervised Interaction consists of three elements: an organisational framework, a contract specification language and a contract management protocol. The organisational framework emphasises the importance of introducing a trusted third party into any automated business transaction. The normative positions of the agents involved in an automated business transaction are explicitly expressed within the contracts that govern agents' behaviour during supervised interaction. This interaction model is designed to provide the web of trust necessary for successful deployment of agent-mediated electronic markets.