The Design of 'The First Experimental Study Exploring DNA Interpretation'

Abstract

This letter discusses a recent study by Dror and Hampikian published in Science & Justice. The authors infer that exposure to domain-irrelevant information caused DNA analysts in a criminal case to misinterpret a complex mixture. However, the “experimental study” is closer to a small observational study than to a controlled experiment designed to detect the effect of “domain irrelevant” information on the judgments of DNA analysts. As a result, problems of confounding and small sample size stand in the way of strong claims that the "experiment" demonstrates contextual bias in this particular case.

Keywords: DNA mixtures, cognitive bias, experimental design