• How to adopt the Trust-based Interaction Design practice

• Key Concepts
• Trust in Multi-Agent Systems
• Reputation in Multi-Agent Systems
• Trust in Organic Computing Systems

• Trust Model

• Tasks
• Identify Sources of Uncertainty
• Define Trust Model
• Define Agent Decisions based on Trust Values
• Design Trust Measurement Infrastructure
• Design a Reputation System

• Bibliography for Trust and Reputation in Multi-Agent Systems

• The Trust Life Cycle

• [Agent Architecture]
• [Interaction Model]
• [Multi-Agent System Architecture]
• [Requirements Model]
• [System Environment Description]

The key principles of trust-based interaction design are:

• Evaluate interactions for their favorability. As agents interact with each other, they accumulate data about each other that can be used in decision making.
• Create a model of other agents' behaviour to make predictions about them. A good trust model allows an agent to make a prediction about the behaviour of a potential interaction partner in future interactions.
• Use knowledge about other agents to minimise risk and interact more efficiently. The knowledge accumulated in the system can help in making decisions that minimise risk by choosing interaction partners with a high probability of a favourable interaction outcome and increase efficiency by reducing the need to repeat interactions or use corrective mechanisms.

The concept of an interaction can here be regarded very generally. Not only are communications with other agents an interaction but also querying of sensors, the use of environmental data, and others. All these interactions are sources of uncertainties that can be mitigated by trust, as described in Trust in Multi-Agent Systems.

As part of this practice, the stakeholders need to perform the following tasks in order to customise the trust lifecycle for a specific system:

• Find sources of uncertainty that can be mitigated by trust (cf. Identify Sources of Uncertainty)
• Select trust models and metrics (cf. Define Trust Model)
• Devise agent decisions based on trust (cf. Define Agent Decisions based on Trust Values)
• Design observation of interactions (cf. Design Trust Measurement Infrastructure)
• (Optional:) Incorporate reputation system (cf. Design a Reputation System)

The best way to read this practice is to first familiarize yourself with its overall structure: what is in it and how it is organized.

Next, review the key concepts for the practice. An especially important concept is Trust in Multi-Agent Systems. After you understand the basic principle of trust, turn your intention to The Trust Life Cycle that describes the relationship between interactions and trust. At this point, you might also want to read some of the seminal papers on trust that are pointed out in the supporting material. Then review the tasks, accessing guidelines and tool mentors associated with each task as needed. You can also access the guidance provided by the practice directly through the Guidance folder.

For step-by-step instructions on how to adopt this practice, see How to adopt the Trust-based Interaction Design practice.