What data do you need to determine influence?
Trying to determine someone level of influence is attractive for a number of reasons, not least to be able to understand how valuable you are as a multiplier in a social network.
There are growing (nine as I write) significant attributes that will affect your influence. The issue is interruption of words...
What authority have you been given by you social graph and what authority can you command (depth)
How credible are you on the topic in question, the closeness to your are of given authority
Proven domain expertise from an independent third party that shows more than common knowledge or willing to stand up and be counted. Think how others whom you are influenced by rate you
Often overlooked but sometime meeting people helps or having someone local is a positive.
Both the relationships between people and how they are connected. Closeness is more than family
Think about the size and potency of your "social graph"
How others whom you influence rate you
The relevancy to local and disparate communities
Is like your bank account it goes up and down. Trust is not fixed and varies by country and culture. It is a mashup of many factors but also needs to be measured as a unique.