The "p"-median clustering model represents a combinatorial approach to partition data sets into disjoint, nonhierarchical groups. Object classes are constructed around "exemplars", that is, manifest objects in the data set, with the remaining instances assigned to their closest cluster centers. Effective, state-of-the-art implementations of…

The prevailing assumption by some that deep processing promotes stronger learning outcomes while surface processing promotes weaker learning outcomes has been called into question by the inconsistency and ambiguity of results in investigations of the relation between levels of processing and performance. The purpose of this literature review is to…

Comments on the original article, "Many forms of culture," by A. B. Cohen. Cohen offered an eye-opening review of how culture means much more than ethnicity within a nation or differences between nations. After developing a much-expanded definition of culture, he concluded, "I have lamented the fact that psychology has focused on some important…

Video game playing has received increased academic interest over the last few decades, particularly with regard to the psychological understanding of addiction. Based on the many studies carried out by the authors, this paper summarises some of the methodological challenges which may arise when studying video game players, including obstacles…

In this commentary, we demonstrate how the potential outcomes framework can help understand the key identification assumptions underlying causal mediation analysis. We show that this framework can lead to the development of alternative research design and statistical analysis strategies applicable to the longitudinal data settings considered by…

Jans, Peters, and De Weerd (2010) examined the studies demonstrating that spatial attention can be split across 2 noncontiguous target locations. They find all these studies to be flawed and conclude that spatial attention only selects a single location at any given time. They do, however, suggest that there could be exceptional circumstances that…

This article compares Donald Campbell's and Donald Rubin's work on causal inference in field settings on issues of epistemology, theories of cause and effect, methodology, statistics, generalization, and terminology. The two approaches are quite different but compatible, differing mostly in matters of bandwidth versus fidelity. Campbell's work…

A key challenge for cognitive psychology is the investigation of mental representations, such as object categories, subjective probabilities, choice utilities, and memory traces. In many cases, these representations can be expressed as a non-negative function defined over a set of objects. We present a behavioral method for estimating these…

This study surveyed 1,234 empirical studies on giftedness, gifted education, and creativity during 1998-2010 (April), using PsycINFO database and targeted journals as main sources, with respect to main topics these studies focused on, methods they used for investigation, and the conceptual spaces they traversed. Four main research topics emerged…

In recent years, single-case designs have increasingly been used to establish an empirical basis for evidence-based interventions and techniques in a variety of disciplines, including psychology and education. Although traditional single-case designs have typically not met the criteria for a randomized controlled trial relative to conventional…

In this article, we note the many ontological, epistemological, and methodological similarities between how Campbell and Rubin conceptualize causation. We then explore 3 differences in their written emphases about individual case matching in observational studies. We contend that (a) Campbell places greater emphasis than Rubin on the special role…

The purposes of this paper are to outline seven types of qualitative data analysis techniques, to present step-by-step guidance for conducting these analyses via a computer-assisted qualitative data analysis software program (i.e., NVivo9), and to present screenshots of the data analysis process. Specifically, the following seven analyses are…

Objective: The purpose of this article is to provide recommendations for writing a successful R13 conference grant proposal for the National Institutes of Health (NIH). Methods: The authors reviewed successful NIH conference grant proposal abstracts. They also reflect on their own experience in writing an NIH conference grant proposal and…

This study identified historical continuities and discontinuities across a century of secondary research published in "English Journal" (1912-1966) and "Research in the Teaching of English" (1967-2011). It highlights considerable methodological continuity across six decades of "English Journal" and some shifts in research emphases that tended to…

Recursive partitioning methods have become popular and widely used tools for nonparametric regression and classification in many scientific fields. Especially random forests, which can deal with large numbers of predictor variables even in the presence of complex interactions, have been applied successfully in genetics, clinical medicine, and…