So far, DI experimental studies involve forensic psycholinguistics research and forensic speaker recognition.

Forensic psycholinguistics research

Evidence, especially in the common law countries, has always been the focus of the dispute resolution processes. Since the emergence of New Evidence Scholarship in the 1960s, the professionals from both theory and practice fields, including those from continental law countries, of which China is generally assumed to belong to, have come to realize that the process of proof, for evidence, is actually a process of information construction rather than discovery of concrete matters and that the process of information construction can not be accomplished atomistically but holistically with a multidisciplinary effort.

 

Witness statements, being dynamic information, can reveal the case-related truth in a direct manner and thus play a vital role in the evidence information construction and attract much attention concerning its credibility assessment. Presently, many approaches, such as polygraph, fMRI, SVA, JMC and son on, have been employed to assess the evidence from the perspectives of physiology, psychology, cognition respectively. Unfortunately, the results from these approaches have not been adopted by legal courts for they could not meet with all the four the requirements from the Daubert Criteria.

 

The research, with a simulation experiment, in which 60 college student volunteers take part,  half of them seeing a violent video and the other half not, will obtain 60 witness statements required to describe the violence in the video , thus 30 true and 30 imaginary. Based on the Principle of Universal Cognitive Competence and Language Adaptive Theory, the similarities and differences of these witness statements can be assumed and will be analyzed both quantitatively and qualitatively in the perspective of the Discourse Information Theory(Du, 2002,2007,2009,2010). It is expected that some specific indicators will be found to assess the credibility of witness statements and that these indicators will also be applied to Polygraph with an aim to enhancing its efficacy.

 

Forensic speaker recognition

Du (2013) suggested the application of discourse information analysis to forensic voice recognition, and believed that the combination of discourse information and speech sound could ensure higher accuracy and precision. The theoretical basis of such a suggestion is that first, information transmission has an effect on the characteristics of speech sound (ibid), and secondly, discourse information is the covert reflection of cognition so that it is difficult for a speaker to exercise a conscious control at the level of discourse information (Du, 2007).

On the basis, forensic speaker recognition research is carried on to exploit the role of discourse information.

References

Du, Jin-bang 2002. An overview of the research of forensic psycholinguistics [J]. Modern Foreign Languages (1).

Du, Jin-bang 2007. A study of the tree information structure of legal discourse [J]. Modern Foreign Languages (1).

Du, Jin-bang 2009. Information flow in discourse [J].  Journal of Foreign Languages (3).

Du, Jin-bang 2010. A study on legal facts constructed via courtroom dialogue [J]. Journal of Guangdong University of Foreign Studies (2).

Du, Jin-bang, Luo, Hong-xiu. 2013. Information-based legal corpus and its use in legal discourse analysis [J]. Journal of Yunment 1 (34):135-140.