How Convinced Should We Be by Negative Evidence?

Since John Locke, the so-called argument from ignorance has been considered to be a fallacy, and is widely represented in informal logic textbooks as an example of incorrect reasoning. This might seem surprising to researchers in many scientific disciplines who routinely draw inferences from negative evidence. Oaksford and Hahn (2004) argued that this discrepancy can be explained within a Bayesian framework. We present here experimental evidence for this view.