In general, however, you can safely expect that people who engage in predictive tasks will underestimate their objective ignorance. Overconfidence is one of the best-documented cognitive biases. In particular, judgments of one’s ability to make precise predictions, even from limited information, are notoriously overconfident. What we said of noise in predictive judgments can also be said of objective ignorance: wherever there is prediction, there is ignorance, and more of it than you think.