The Thesis Paradox: An Empirical Study of the Impact of Doctoral Research

With an annual production of more than 41 000 Ph.D.s per year in the US alone (NSF, 2004), doctoral theses are expected to have a considerable impact on academic knowledge development. Previous research on dissertations examined topics ranging from quality and time-to-degree of a doctoral education (e.g., Ziolkowski, 1990; Bowen, Lord & Sosa, 1991; Gonzalaz, 1996; Katz, 1997), to the skills required of doctoral candidates (e.g., Isaac, Quinland & Walker, 1992; Barry, 1997), pre-thesis and post-thesis publication productivity (e.g., Lee, 2000; Anwar, 2004), and the role of dissertations as information sources (e.g. Boyer, 1973; Davidson, 1977). Despite these numerous studies on Ph.D.s and Ph.D. theses, there is a current lack of information concerning the scientific impact of this mode of diffusion.

This paper assesses the impact of theses based on their citation frequency in peer-reviewed papers and measures the evolution of this impact over time. Theses are becoming more available in electronic form (e.g., Networked Digital Library of Theses, 2005); hence, one can assume that they are increasingly consulted and used by researchers.