The world of fiction writing—nebulous, intuitive and founded upon artistic pretense—is often far removed from the idea of statistical analysis. The very idea that writing style could be distilled into data and spreadsheets and graphs would strike many as preposterous. Yet that lofty (and perhaps preposterous) idea is the aim of this study. What can statistics tell us about the writing process?

The last ten years in the literary world have been utterly dominated by one author and one series of books: J. K. Rowling’s Harry Potter series. The six published Harry Potter books (a seventh is still on the way) have grossed billions of dollars around the world, making Harry and his friends international superstars, and making Ms. Rowling one of the world’s richest persons. Thus it would seem only natural to make Ms. Rowling and her fiction writing the subject of this study.

Indeed, beyond the simple dollars-and-cents reasoning, Ms. Rowling is an interesting subject for study because we have seen her grow as a writer almost before our very eyes. Before her first novel, Harry Potter and the Sorcerer’s Stone, Ms. Rowling was an unpublished amateur writing out her stories on napkins in cafes in Edinburgh, Scotland. Now, six novels later, we have had the chance to see her develop as a writer before the world’s watchful eyes.

The question for this study, therefore, is what, through statistical analysis, can we learn about Rowling’s writing and its evolution over the last ten years? What characterizes her unique style, and how has it changed as she has progressed through her series?

Writing in Entertainment Weekly on July 6, 2003, the author Stephen King reviewed Ms. Rowling’s fifth book, Harry Potter and the Order of the Phoenix. Among his observations he said:

“As a writer, however, she is often careless (characters never just put on their clothes; they always get "dressed at top speed") and oddly, almost sweetly, insecure. The part of speech that indicates insecurity ("Did you really hear me? Do you really understand me?") is the adverb, and Ms. Rowling seems to have never met one she didn't like, especially when it comes to dialogue attribution.”

King’s observation about parts of speech provides the basis for this study. What do the different parts of speech Ms. Rowling employs teach us about her writing? Most significantly, how has she changed, and, based on her past work, can we predict the writing mix of her seventh and final Harry Potter book? To learn more about these questions the study will use the methods of statistics to analyze the writing in each of the first six Harry Potter novels. To mix it up, and to provide a context for external comparison, we will also examine one of Mr. King’s one recent novels, Dreamcatcher, in the same fashion.