Guesstimate: An app for making decisions with confidence (intervals)

Abstract

I’m happy to announce the public beta of Guesstimate, a web app for creating models and Fermi estimates with probability distributions.  It’s free, open source, and relatively easy to use. . Effective Altruism is largely about optimizing expected value.  Expected value estimates often have high uncertainty for multiple inputs, but the uncertainty of the outputs is rarely calculated.