Ruscio and colleagues (Ruscio, Seaman, D'Oriano, Stremlo, & Mahalchik, this issue) provide a thoughtful empirical analysis of 22 different measures of individual scholarly impact. The simplest metric is number of publications, which Simonton (1997) found to be a reasonable predictor of career trajectories. Although the assessment of the scholarly…

Ruscio et al. (Ruscio, Seaman, D'Oriano, Stremlo, & Mahalchik, this issue) have provided an impressively comprehensive conceptual and empirical psychometric analysis of 22 modern-day citation measures. Their analyses show that although numerous measures have been developed to ameliorate perceived limitations of Hirsch's (2005) "h" index (which is…

Ruscio and colleagues (Ruscio, Seaman, D'Oriano, Stremlo, & Mahalchik, this issue) have done a great service by systematically comparing indices of scholarly impact. Three aspects of their work are particularly valuable: (1) Their assessment of the proliferating collection of metrics, whose development has become something of a cottage industry,…

In their article Ruscio et al. (Ruscio, Seaman, D'Oriano, Stremlo, & Mahalchik, this issue) present a comparative study of some of the different variants of the "h" index. The study evaluates a total of 22 metrics, including the "h" index and "h"-type indices, as well as other conventional measures. The novelty of their work is to a large extent…

Ruscio et al. (Ruscio, Seaman, D'Oriano, Stremlo, & Mahalchik, this issue) write of a thing with which scientists and scholars are all too familiar, the assessment of published research and of its authors. The author was startled to discover how little the agenda of the paper seems to engage with factors one relies on for salary and promotion…

The target article seems to provide yet another illustration of the classic "It don't make no nevermind" principle in statistical analysis. In particular, relatively simple measures appear to do approximately as well as more complex measures do, even including indicators that represent nonlinear transformations of the simpler measures. The authors…

The suggested role for assessment in developing "Roadmaps for Learning" has potentially important implications for the learning of second or foreign languages in school, a major concern of applied linguistics. In this response, the authors consider how the findings of a detailed ethnographic study of classroom-based assessment in two foreign…

This article describes an exploration of the distinction between typological and factorial latent variables in the domain of personality theory. Traditionally, many personality variables have been considered to be factorial in nature, even though there are examples of typological constructs dating back to Hippocrates. Recently, some…

Von Davier, Naemi, and Roberts (this issue) present a nice summary of the statistical ambiguity often encountered in making distinctions between qualitative and quantitative constructs. In this commentary, the author begins with two broad points. The first is that the mixture/factor arguments are most intriguing when firmly embedded in a…

In the focus article of this issue, von Davier, Naemi, and Roberts essentially coupled: (1) a short methodological review of structural similarities of latent variable models with discrete and continuous latent variables; and (2) 2 short empirical case studies that show how these models can be applied to real, rather than simulated, large-scale…

The notion that there is often no clear distinction between factorial and typological models (von Davier, Naemi, & Roberts, this issue) is sound. As von Davier et al. state, theory often indicates a preference between these models; however the statistical criteria by which these are delineated offer much less clarity. In many ways the procedure…

The literature on bibliometric indices for assessing scholarly impact, in particular the "h" index (Hirsch, 2005) and its many variants, is extensive, but nevertheless Ruscio and colleagues (this issue) succeed in making a valuable contribution. They have made the effort of collecting publication and citation data for no less than 1,750…

Von Davier et al. (this issue) describe two analyses that aim at determining whether the constructs measured with a number of observed items are categorical or continuous in nature. The issue of types versus traits has a long history and is relevant in many areas of behavioral research, including personality research, as emphasized by von Davier…

The challenge for a discussant of the Humphry article in this issue is that the profundity of the simple insights of the article, and the lucid arguments by which the insights are sustained, might be easily overlooked, undervalued, or misconstrued. At the risk of repeating major inferences already presented, one may note that the article…

Compared to traditional test theory, where person measures are typically referenced to the distribution of a population, item response theory allows for a much more meaningful interpretation of measures as they can be directly compared to item locations. However, Stephen Humphry shows that the crucial role of the unit of measurement has been…