The generational gap of science: a dynamic cluster analysis of doctorates in an evolving scientific system

Abstract

The features of science and technology (S&T) systems change over time. Simultaneously, at an individual level, the characteristics of actors in these systems also change concomitantly. In this study, the characteristics of doctorates in a changing S&T system are analyzed. This is performed by a series of cluster analyses on doctorates-with the goal of identifying shifting profiles-in strategic periods spanning three decades, which represents milestones in an evolving S&T system. A series of archetypal profiles of doctorates are identified, including changes to the relative weights of each of them, along with a pattern of alternating convergence and divergence over time on the characteristics of these doctorates.

PhD funding as a determinant of PhD and career research performance

“…This may be related to the development of the academic system in Portugal, which is growing fast in terms of new doctorates and young applicants to doctoral studies (according to Santos, Horta, and Heitor (2016), more new doctorates were awarded in the past decade than in the previous decades altogether). These younger applicants may also be perceived as potentially more productive and internationally oriented (Santos and Horta 2015; this is aligned with the fostering of the internationalization of the scientific system -as non-Portuguese nationals also tend to be more successful in the award of PhD funding as Table 3 shows). Despite the academic system offering fewer stable employment opportunities (Araújo 2008), Portuguese universities need to further qualify their academic body, and high general unemployment rates (Santos, Horta, and Heitor 2016) make the option to pursue a PhD possibly more appealing to younger generations with tertiary degree qualifications.…”

“…According to the Census exercise of 2011, 56% of the doctorate holder population residing in Portugal were male (also 56% in the sample), with an almost inexistent rate of unemployment (0.06%). Most doctorate holders residing in Portugal are Portuguese nationals (94%; 96% in the sample) and the most recently minted doctorates take more postdoctoral positions than in the past (GPEARI 2011;INE 2011;Santos and Horta 2015). Data provided by the Portuguese Ministry of Science and Education distribute the doctorate holders in the population by field of knowledge from 1970 to 2013 as follows: social sciences (26%; 24% in the sample), engineering and technology (25%; also 25% in the sample) and natural sciences (23%; 22% in the sample), humanities (14%; 13% in the sample), medical sciences (10%; also 10% in the sample), and agriculture (2%; 6% in the sample).…”

The research agenda setting of higher education researchers

“…The first stage of the analysis employs cluster analysis to identify specific profiles and create a typology of research agendas. In the literature, cluster analysis has been used in a variety of contexts, including the study of behavioral patterns (e.g, Chou, 2008), science and technology indicators (e.g, Almeida et al, 2009), and profiles of the careers of researchers (Santos and Horta, 2015). In the analysis undertaken for this article, a TwoStep clustering algorithm is used, which offers several advantages over traditional clustering procedures.…”

“…It allows for the use of both categorical and continuous variables, which is not possible with traditional clustering methods (Norusis, 2012); it is compatible with very large datasets (Zhang et al, 1996); and it is capable of statistically determining the optimal number of clusters (see Chiu et al, 2001 for a detailed description of this procedure). The clustering procedure used log-likelihood estimation, given that the reported Euclidean distance performed poorly in this context (see Santos and Horta, 2015). The model fit was evaluated by means of the average silhouette measure of cohesion and separation ranging from -1 to 1.…”

The Impact of Publishing During PhD Studies on Career Research Publication, Visibility, and Collaborations

“…This was because individuals who have left academia might be holding non-research positions and are thus less likely to keep on publishing (Santos and Horta 2015).…”