Research on subjective bias cognition effect in handwriting identification

Abstract

This article starts from the point of view that handwriting examination is dependent on empiricism and by analyzing the core steps of handwriting identification explains that it might be influenced by subjective bias. In practice, examiners cannot avoid biases in decision-making; instead, we must accept the existence of subjective bias in handwriting identification and then discuss its impact; for instance, feature selection in the process of comprehensive evaluation, which involves a comparison of the number and quality of similarities and differences between a questioned sample and the references. While we conclude that comprehensive evaluation is the most important step in the identification process, industries in China do not stipulate explicit and transparent criteria for it, making it hard to numerically quantify the characteristics of handwriting identification. In this article, forensic examiners' opinions on handwriting identification were obtained through a survey. One finding was that most handwriting examiners believe that handwriting identification is subject to subjective bias. In addition, they believe that the subjective cognition of handwriting identification can somehow help actively produce the correct opinion; before the examination, most handwriting examiners think that they should understand the context and so on. Finally, through the questionnaire, which contained variations such as the same case with different background information, different cases with the same background information, and the same case with or without context, it was concluded that handwriting identification does have certain subjectivity. However, which kind of factors influence this subjectivity is not presently clear. Furthermore, it is difficult to control uncertainties when forming an opinion on identification. An alternative way is to perform scrutiny after the formulation of handwriting opinions; for example, internal and external reviews such as appearing in court.