Distributed Fact Checking.

We formulate the problem of fake news detection using distributed inexpert agents. We consider the source for news/statements as a binary source (to model true vs. false statements). Upon observing news, each agent labels the news as true or false, which equals the validity of the statement with some probability depending on the reliability of the agent. In other words, each agent is viewed as a Binary Symmetric Channel (BSC) that misclassifies each statement with some error probability. For an algorithm that estimates the validity by thresholding a linear combination of the individual agents’ labels, we characterize the optimal weights and threshold to minimize the probability of error. We establish an upper bound on this probability of error as well as the naive majority rule.