Task: Design Trust Measurement Infrastructure
Design the elements of the system that allow the derivation of experiences.
Disciplines: Architecture
Purpose

Provide the infrastructure required to derive trust values.

Relationships
Parent Practices
InputsMandatory:
    		Optional:
      Outputs
        Main Description

        In order to measure the trust value, contracts have to be established and the results of interactions have to be compared to these contracts. For this purpose, the desired and the actual result of interactions need to be determined and transformed into an experience. Depending on the interaction, the contract can either be stated explicitly or even negotiated in a separate interaction or be defined implicitly.

        In any case, experiences have to be stored in the system and made available to the trust model. The trust model will have to be able to access the experiences and create a trust value from them. The value will then have to be available to the agent or a reputation manager.

        Existing patterns for this infrastructure should be employed whenever possible.

        Steps
        Specify the contents of contracts
        This step has to be performed for each interaction with different contracts. The designer has to make sure that all relevant aspects of the interaction are captured in the contract. Depending on the actual interaction, this includes prices, delivery deadlines, maximum response times, etc.
        Define the data stored in experiences

        Experiences can store pre-processed data, such as deviations from the contract, or raw data, e.g., the contract and the actual result of the experience. Depending on the trust model used, only relevant information must be stored. However, discarding information can also mean that the system is not flexible w.r.t. later changes in the trust model. The designer has to make a conscious and well documented decision which data is kept and which pre-processing steps have to take place.

        Design interfaces to the trust model and the agents
        In order to make the data available to the trust model and to the agents, appropriate interfaces have to be defined. If a reputation system is used, make sure that it can also access the trust values or it automatically receives new trust values (pull or push).
        More Information
        Supporting Materials
        Whitepapers

        This material is made available under the Creative Commons—Attribution-ShareAlike License v3.0.

        © Copyright 2013, 2014 by Institute for Software & Systems Engineering, University of Augsburg
        © Copyright 2015 by Chalmers | University of Gothenburg
        Contributors
        Contact: Jan-Philipp Steghöfer
        Impressum

        Parts of this material is based on the Eclipse Process Framework Practice Library, distributed under the Eclipse Public License V1.0.