Jack the Writer: A Verbal & Visual Analysis of the Ripper Correspondence is a different approach to the subject of 'Ripperology'. In this book, the author, Dirk Gibson, provides a quantitative content analysis of the letters. Gibson first grounds this study of the Jack the Ripper letters in an analysis of the legitimacy of the documents. The dialectic method is used to carefully consider the authenticity of these letters. The largest extant collection of Jack the Ripper letters is provided in this book, approximately 250 in number.

Gibson made a holistic judgment about the authenticity of individual letters, based on predictions and warnings of future crimes that actually occurred, inclusion of information about the crimes only known by the killer, handwriting, topic, resemblance to other letters, specific content, blood smears, and linguistic criterion. Roughly half of the letters might have been genuine, based on these factors. In a sense it doesn’t matter, because content analysis reveals that the style and content of the legitimate and unauthentic missives were the same.

Interestingly, most scholars of the Ripper crimes dismiss the letters as being unimportant, echoing the sentiments of the case investigators at the time. Critics assert that the letters were bogus, and/or meaningless.

Nevertheless, since the time of the crimes there has been debate over the legitimacy of these communications. Dr. Thomas Dutton was the Admiralty Surgeon and Agent of the Chichester Division, Physician to Uxbridge Road Maternity and Child Welfare Clinic and the Royal Defense Corps He was also a handwriting analyst and expert at microphotography. He studied 128 Ripper letters, He concluded that 34 items were produced by the same person, despite attempts to disguise the handwriting as that of an uneducated man or a clerk.

Critics of the letters said that none of them were written by the killer, or that between two and four could be authentic. It was widely believed at the time that the letters were the work of a journalist named Best or Bullen. Detectives working the case, law enforcement administrators, and coroners disbelieved in the authenticity of the letters.

The complete text of each of the extant letters is presented in two chapters. The missives from 1888 are shared in one chapter, and the post-1888 letters in another.

The heart of this study, the content analysis, resulted in five thematic categories; dominant themes, meaningful themes, major themes, “large” minor content themes, and “small” minor content themes. The dominant content themes appeared on average in 69.26 % of the letters, the major themes were found in 60% of the missives, and the meaningful theses occurred in 23.3% of the items of correspondence. The “large” minor theme category themes were present in 9 letters, compared to 3.76 letters in the “small” minor theme category.

The three dominant themes were; crime predictions and warnings (mentioned in 204 letters, taunting and ridiculing the police (198 letters), and use of the term “boss” (142):