From: Development and verification of an agent-based model of opinion leadership
Variablea | Specifications |
---|---|
Global variables | Values can be accessed by all agents |
Announced evidence—new evidence made known to agents, expressed as a probability | Value (1-100) based on a random normal distribution around a mean determined by the model user, visible to the agents |
Credibility of the evidence announcer—probability that what the announcer says is true | Value (1-100) of the credibility of the random individual agent that announces the evidence, made visible to other agents |
Agent set variables | Value determined by membership in a group |
Unearned authority (UA)— authority resulting from the agent’s position | Defined by position: UA of staff nurses = 50, UA of educators = 80, UA of nurse managers = 90 |
Agent variables | Each agent has unique value assigned by the model program based on model user input of the mean |
Prior-belief—individual agent’s level of confidence as to the probability of a given proposition | Agent belief at the beginning of process. Initial setting is random normal distribution (1–100) with model user adjusted mean. Sequential values are determined by the belief revision process. |
Earned authority—authority based on a person’s performance | Random normal distribution (1–100) with model used adjusted mean |
Motives—probability that an individual takes a course of action based on epistemic (truth) or pragmatic (utility) goals | Random normal distribution (1–100) with model user adjusted mean. <50 = pragmatic, ≥50 = epistemic. |
Procedure-based agent variables | Values calculated based on agent procedures |
Visibility—agent’s behaviors are made known to others | Prior belief combined with a threshold based on motives. Pragmatic agents have a lower prior-belief threshold for visibility |
Credibility—evaluation about the probability that what the agent says is true | Weighted combination of earned and unearned authority. Weight based on visibility of agent. |
Assessed evidence— agent’s evaluation of the truth value of new evidence | Absolute value of the difference between an agent’s prior belief and the announced evidence |
Assessed credibility of announcer—agent compares his own perceived credibility with that of the announcer | Absolute value of the difference between an agent’s own credibility and credibility of the announcer who shares the new evidence |
Uncertainty—agent unable to assess the truth value of the evidence | Based on a threshold of evidence and credibility assessments. Determines need for advice |
Availability— agent meets the threshold requirements to act as an advice giver | Visible agents with a model user adjusted threshold of credibility available for giving opinion to other agents seeking advice |
Get advice— seek out available agents as a resource to decrease uncertainty about evidence | Agents who need advice create links with available opinion resources (potential OLs). Reassess evidence and announcer credibility based on the beliefs and credibility of the opinion resources |
In-link—incoming communication from an uncertain agent to an agent available to give advice | Number of links an available agent receives from uncertain agents |
Out-link—outgoing communication from an uncertain agent | Number of links an uncertain agent sends to available agents |
New belief— revised probability assessment of the evidence | Agents change their beliefs based on their prior beliefs and a threshold assessment of the evidence. Individual agent’s new belief replaces the prior belief for the next sequence (tick). If the assessment does not meet the threshold for revising belief, the new belief remains the same as the prior belief. Aggregate of individual belief revision changes the overall community context in terms of consensus belief. |