Recent work in artificial intelligence has increasingly turned to argumentation asa rich interdisciplinary area of research that can provide new methods related toevidence and reasoning in the area of law. In this book, DouglasWalton providesan introduction to basic concepts, tools, and methods in argumentation theoryand artificial intelligence as applied to the analysis and evaluation of witnesstestimony. He shows how witness testimony is by its nature inherently fallibleand sometimes subject to disastrous failures. At the same time, if used properly,such testimony can provide evidence that it is not only necessary but inherentlyreasonable for logically guided legal experts to accept or reject a claim. Waltonshows how to overcome the traditional disdain for witness testimony as a typeof evidence shown by logical positivists and the views of trial skeptics who doubtthat trial rules deal with witness testimony in a way that yields a rational decisionmakingprocess. This book will be of interest to those who work in the areas ofanalytical philosophy, informal logic, artificial intelligence, and law.