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Disputation: Lisbeth Fullu Skyberg

Cand. polit Lisbeth Fullu Skyberg will be defending the thesis Testimony and evaluations of credibility for the degree of Ph.D.

Original title: Rettslige forklaringers troverdighet. En teoretisk, historisk og empirisk undersøkelse av bevismuntlighetens betydning for vurdering av troverdighet i straffesaker.

The disputation will be held in Norwegian

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Lisbeth Fullu Skyberg

Photo: Karl-Fredrik Tangen

Trial lecture - time and place

Adjudication committee

  • Professor Vidar Halvorsen, University of Oslo (leader)
  • Associate professor Ellen Wessel, Norwegian Police University (1. opponent)
  • Professor emeritus Kjell Å Modeer, Lund University (2. opponent)

Chair of defence

Head of Department May-Len Skilbrei


  • Professor Ola Mestad


How do judges evaluate credibility in criminal cases and based on what? From the enactment of the Criminal Procedure Act in 1887 and until now, the principle that testimony [evidence] must be presented orally and directly to the court has been paramount in criminal law. Although the principle of oral and direct testimony has several rationales, one of the most important is that this presentation form will make the judges evaluations of credibility more accurate. In his book on court proceedings, Jo Hov expresses the belief in directly presented oral evidence as an epistemological tool in this pointed remark: “it has been said that papers don’t blush”.

In this phd dissertation, the historical and contemporary legal grounds for the chief role attributed to the principle of oral and direct testimony in criminal proceedings are explored. How oral and direct testimony influences and informs judges’ assessments of credibility is also examined. 

What influence legal evaluations of credibility in practice
Through theoretical and historical analysis of legal conceptualizations of credibility, the reading of judgments, observations of court deliberations and interviews with judges, the phd-thesis develops the contours of an empirically based credibility assessment theory/theory of sources of credibility, in analogy to the more traditional and well established theory of sources of law. 

Inherent in the principle of free evaluation of evidence is the absence of formal methodology with regard to evaluation of evidence. Nevertheless, the analysis brings to light an informal structure as far as credibility assessments are concerned. The purpose of the analytical reconstruction of a credibility assessment theory based of five elements is to highlight tacit and implicit knowledge applied by courts, so that the criteria applied in credibility assessments can be subject to discussion.

The need for knowledge
The analysis shows that support by the behavioral sciences of the credibility assessment theory varies between the five elements. The analytical reconstruction of a credibility assessment theory thereby provides a basis for discussion both from a psychological and from a legal historical perspective, both with greater attention to what should influence credibility assessments in courts, what should not, how and why.


Published June 3, 2019 1:11 PM - Last modified Dec. 10, 2019 5:01 PM