Applying Hierarchy of Expert Performance (HEP) to investigative interview evaluation: strengths, challenges and future directions

Abstract

The purpose of this paper is to systematically examine the research literature on the decision of expert interviewers within the theoretical framework of the Hierarchy of Expert Performance (HEP). After providing an overview of the HEP framework, existing research in the investigative interviewing at each of the eight levels of the HEP framework is reviewed. The results identify areas of strength in reliability between experts’ observations (Level 2) and of weakness in reliability between experts’ conclusions (Level 6). Biases in investigative interview experts’ decision making is also revealed at biasability between expert conclusions (Level 8). Moreover, no published data are available in reliability within experts at the level of observations (Level 1) or conclusions (Level 5), biasability within or between expert observations (Level 3 and 4) and biasability within expert conclusions (Level 7). The findings highlight areas where future research and practical endeavour are much needed for the investigative interview.

Key words:

• bias
• decision making
• forensic/investigative interview
• HEP
• Hierarchy of Expert Performance
• professional judgements

Author statement

We are grateful to the anonymous reviewers who provided their invaluable suggestions to improve this manuscript. This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.

Ethical standards

Declaration of conflicts of interest

Ching-Yu Huang has declared no conflicts of interest

Ray Bull has declared no conflicts of interest

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Notes

1 In countries where investigative interview protocols have been systematically implemented, such as the USA, the UK, Israel and Japan, the interviewers are trained experts in both conducting and evaluating the interviews. Sometimes, researchers specialized in this area of research may also be call to serve as expert witnesses in evaluating the interviews. In this paper, we use ‘interviewers’ to refer to the person conducting the interviews, and ‘experts’ to refer to the person evaluating the interviews, who can be either an experienced and well-trained interviewer or a researcher with relevant expertise serving as an expert witness.

2 Although it is not always apparent if something is relevant or not, and there are instances where it is hard to determine what is irrelevant, there are nevertheless instances that information is clearly not relevant. For example, the race of the interviewee is irrelevant and should not contribute to determining their credibility. It is not within the aim or scope of this paper to determine what is relevant, or irrelevant, but to make the point that there is some information that is irrelevant, and if it impacts the decision making, it is biasing (see discussion of this matter by the National Commission on Forensic Science, 2015).