The evolution of testimony

Building on the claims that (i) testimony is not a sufficient condition of truth, (ii) biases affect testimony and its evaluation, but (iii) testimony is an important source of knowledge, one important step in the evolution of legal testimony is the move from a priori rules of exclusion (given alleged biases, social or cognitive) to default admission with a posteriori assessment (given the expected benefits in terms of accuracy). A similar step is the move from hearsay ban to hearsay ban exceptions (again, given the expected benefits in terms the accuracy). On the other hand, artificial intelligence poses new challenges to the legal use of testimony, especially if we will employ, as witnesses, devices that answer questions: this could come at the expense of safeguards (like the right to confrontation) set for the benefit of criminal defendants.