Dimensional comparison theory (DCT; Möller & Marsh 2013:Psychological Review, 120(3), 544-560), first formulated 10 years ago, describes individuals' internal comparison processes applied between different areas of their lives. Dimensional comparisons explain the seemingly counterintuitive phenomenon that students' verbal and mathematical…

To address the seven guiding questions posed for authors of articles in this special issue, we begin by discussing the development (in the late 1970s-early 1980s) of Eccles' expectancy-value theory of achievement choice (EEVT), a theory developed to explain the cultural phenomenon of why girls were less likely to participate in STEM courses and…

In the past decade, moderated mediation analysis has been extensively and increasingly employed in social and behavioral sciences. With its widespread use, it is particularly important to ensure the moderated mediation analysis will not bring spurious results. Spurious effects have been studied in both mediation and moderation analysis, but this…

Education and income are strong predictors of health and longevity. In the last 20 years many efforts have been made to understand if these relationships are causal and what the possible role of policy should be as a result. The evidence from various studies is ambiguous: the effects of education and income policies on health are heterogeneous and…

Human intelligence (also called general intelligence, "g," or Spearman's "g") is a highly useful psychological construct. Yet, since the middle of the 20th century, gifted education researchers have been reluctant to discuss human intelligence. The purpose of this article is to persuade gifted education researchers and…

Item response theory (IRT) models are the main psychometric approach for the development, evaluation, and refinement of multi-item instruments and scaling of latent traits, whereas multilevel models are the primary statistical method when considering the dependence between person responses when primary units (e.g., students) are nested within…

It is an exhilarating and important time for conducting research on learning, with unprecedented quantities of data available. There is a danger, however, in thinking that with enough data, the numbers speak for themselves. In fact, with larger amounts of data, theory plays an ever-more critical role in analysis. In this introduction to the…

There are usually limited user evaluation of resources on a recommender system, which caused an extremely sparse user rating matrix, and this greatly reduce the accuracy of personalized recommendation, especially for new users or new items. This paper presents a recommendation method based on rating prediction using causal association rules.…

This report was commissioned by the Council of Exceptional Children (CEC) Board of Directors and a workgroup comprising seven special education researchers (Bryan Cook, Chair; Virginia Buysse; Janette Klingner; Tim Landrum; Robin McWilliam; Melody Tankersley; and Dave Test) who developed, vetted, and piloted the new standards for determining…

An estimated 2.5 million people worldwide are living with multiple sclerosis (MS), and this disease may be increasing in prevalence. MS is a disease of the central nervous system that is associated with heterogeneous symptoms and functional consequences, and the current first-line disease-modifying therapies often become ineffective later in the…

Identity fusion is a relatively unexplored form of alignment with groups that entails a visceral feeling of oneness with the group. This feeling is associated with unusually porous, highly permeable borders between the personal and social self. These porous borders encourage people to channel their personal agency into group behavior, raising the…

A distinction is proposed between measures and predictors of latent variables. The discussion addresses the consequences of the distinction for the true-score model, the linear factor model, Structural Equation Models, longitudinal and multilevel models, and item-response models. A distribution-free treatment of calibration and…

Intervention integrity or adherence describes qualities of carrying out an intervention plan and in research is fundamentally linked to experimental validity questions addressed by measurement of independent and dependent variables. Integrity has been well described in conceptual writing but has been a continuing thorny subject in research and…

Indefinite symmetric matrices that are estimates of positive-definite population matrices occur in a variety of contexts such as correlation matrices computed from pairwise present missing data and multinormal based methods for discretized variables. This note describes a methodology for scaling selected off-diagonal rows and columns of such a…

Qualitative manuscripts occupy a multidimensional world and can vary by their "latitude" (where they are with respect to the humanities and sciences), "longitude" (where they are with respect to the length and number of data excerpts), and "altitude" (where they are with respect to the level of theorizing). In this article, I discuss these 3…