Testing Authorship in the Personal Writings of Joseph Smith Using NSC Classification

In a co-authored article my colleagues and I employed both delta and nearest shrunken centroid (NSC) classification in an authorship analysis of the Book of Mormon (Jockers et al., 2008). Our results suggested that several men involved in the early formation of the Mormon Church might have been contributors to the Book of Mormon. For reasons detailed in that article, and summarized again here, we excluded Mormon prophet Joseph Smith from our authorship tests. The work presented here reevaluates our decision to exclude Smith and employs both supervised classification and unsupervised clustering in order to explore the stylistic consistency between documents attributed to Smith (but written in the handwriting of Smith's 24 different scribes) and documents in Smith's own hand.