How trust and distrust propagate in social network Explain.

 Propagation of Trust and Distrust

The end goal is to produce a final matrix F from which we can read off the computed trust or distrust of any two users. In the remainder of this section, we first propose two techniques for computing F from CB. Next, we complete the specification of how the original trust T and distrust D matrices can be combined to give B. We then describe some details of how the iteration itself is performed to capture two distinct views of how distrust should propagate. Finally, we describe some alternatives regarding how the final results should be interpreted.

Approaches to Trust Propagation

A natural approach to estimate the quality of a piece of information is to aggregate the opinions of many users. But this approach suffers from the same concerns around disinformation as the network at large: it is easy for a user or coalition of users to adopt many personas and together express a large number of biased opinions. Instead, we wish to ground our conclusions in trust relationships that have been built and maintained over time, much as individuals do in the real world. A user is much more likely to believe statements from a trusted acquaintance than from a stranger. And recursively, since a trusted acquaintance will also trust the beliefs of her friends, trusts may propagate (with appropriate discounting) through the relationship network.

An approach centered on relationships of trust provides two primary benefits. First, a user wishing to assess a large number of reviews, judgments, or other pieces of information on the web will benefit from the ability of a network of trust to present a view of the data tailored to the individual user, and mediated through the sources trusted by the user. And second, users who are globally well-trusted may command greater influence and higher prices for goods and services. Such a system encourages individuals to act in a trustworthy manner, placing positive pressure on the evolving social constructs of the web. Indeed, social network theory and economics have considered a variety of facets of this general subject.