This paper examines evidence for relationships among individual differences (IDs) in L1 achievement, L2 aptitude, and L2 achievement. It begins by providing an overview of my academic journey from L1 educator to L2 researcher and explains the development of the Linguistic Coding Differences Hypothesis (LCDH). Next, I review Peter Skehan's…

In this paper, we aim to differentiate the internal and external horizons of "fusion." "Fusion" in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the…

Many developmental mathematics programs emphasize computational fluency with the assumption that this is a necessary contributor to student success in general studies mathematics. In an effort to determine which skills are most essential, scores on a computational fluency test were correlated with student success in general studies mathematics at…

Standardized admissions tests such as the SAT (originally stood for "Scholastic Aptitude Test") and the ACT measure only a narrow segment of the skills needed to become an active citizen and possibly a leader who makes a positive, meaningful, and enduring difference to the world. The problem with these tests is that they promised, under…

In this article, I describe studies conducted over 25 years with secondary and post-secondary L2 learners in the United States. The evidence from these studies shows that there are important connections between students' early L1 skills and their L2 aptitude and L2 proficiency and that individual differences in students' L1 skills in elementary…

Common forms of testing of student understanding of science content can be misleading about their understanding of the nature of scientific thinking. Observational astronomy integrated with related ideas of force and motion is a rich context to explore the correlation between student content knowledge and student understanding of the scientific…

An important but too infrequently considered methodology that can be used in research, especially research focusing on Pearson's "r" (B. Walsh, 1996) or the multiple "R" (see B. Thompson, 1992) involves testing for moderator or mediator variable effects. As explained by M. Gall, W. Borg, and J. Gall (1996), moderator analysis…