Uncertainty affects nearly everything we do. Virtually every decision we make involves uncertainty of one kind or another. However, uncertainty does not come naturally to people’s minds.Wheneverwe can (and sometimeswhenwe can’t),we substitute an imagined certainty thatwe find more comfortable and easier to plan against. Statistics offers tools to deal with uncertainty, principally through probability. There are many models and methods in a statistician’s toolkit. Which to use when, and how to createmore when necessary are the typical tasks facing users of statistical methods. Every application of statistics has to be sensitive to the institutional context in which the problem arises. In the case of forensic evidence, the institutional structure includes both the organizations for which forensic scientists work and the legal structures to which they ultimately report.