Textual kidnapping - a case of plagiarism among three student texts?

The linguistic analysis of text for forensic purposes has been developing rapidly over the past decade. However, the discipline has done so in spite of a lack of established tools, methods or theories. Writers in the field have been contributing to a suite of techniques and methods of analysis and this paper offers some further tools for the statistical analysis of text. A case of alleged plagiarism is investigated through the use of two computer programs: Vocalyse and File Comparison. The discussion demonstrates how a quantitative statistical investigation of hapaxes, unique and common lexical and closed class vocabulary can support a qualitative textual analysis, in order to establish whether a case of plagiarism has occurred. The statistical tools and methods explained are offered as examples for use and development by readers.