danah asks why bi-directional networks? http://www.zephoria.org/thoughts/archives/2005/11/29/attention_netwo.html
My comment:
Depends on the goals of the system. I don’t think having online social networks that accurately represent “real” social networks is the higher order goal of most systems, though they would be valuable from a research perspective. If you are trying to find a date through a friend, or a job recommendation, etc., that people actually reciprocate a friendship or work together is very meaningful. In Wallop we thought about having unidirectional networks but from a statistical perspective, when examining interaction behavior, it makes sense to represent relationships as bidirectional because you want to normalize the strength of each relationship by each person’s other relationships. That is, a friendship is more meaningful if both parties interact with each other more than with other people. Otherwise the most active person (sometimes known as a spammer) comes up as everyone’s best friend.
