Fractions are foundational for success in algebra and STEM, but they are notoriously difficult for students. In past work, two separate branches of research from psychology and math education have studied fractions knowledge using different, isolated approaches. In this dissertation, I synthesize research from both fields about proportional…

Mathematical performance plays a vital role in students' academic development. Studies have shown that some basic cognitive processes, including inductive reasoning, are critical for the development of mathematical performance. However, little empirical evidence has been accumulated regarding the association between inductive reasoning and…

Background: The role of gender in both spatial and mathematics performance has been extensively studied separately, with a male advantage often found in spatial tasks and mathematics from adolescence. Spatial reasoning is consistently linked to mathematics proficiency, yet despite this, little research has investigated the role of spatial…

This study reviews how slope is developed in expository materials across a seven-textbook series. Slope development is analyzed using a framework of five slope components to describe which components are used and connected, and by investigating accompanying levels of covariational reasoning. Findings suggest that the series describes slope from…

We describe how we supported middle-school students developing meanings for quadratic growth by bringing together three theoretical framings and designing a task sequence grounded in that framework. Specifically, this framework was assembled from the research on students' quantitative and covariational reasoning, Realistic Mathematics Education,…

The development and use of learning trajectories is a body of research that has made enormous contributions to the field of mathematics education, offering insight into the teaching and learning of topics at all levels. Simultaneously, the work of building learning trajectories can benefit from explicitly adopting an anti-deficit stance,…

Emergent graphical shape thinking (Moore & Thompson, 2015) is a way of reasoning that is critical across numerous STEM fields. However, evidence indicates that the underlying component ideas for emergent thinking are underdeveloped in school mathematics education (e.g., Thompson & Carlson, 2017), and few studies directly report on…

Supporting students' mathematical reasoning is an important goal of mathematics instruction, but can be challenging for many teachers .We report the results of a study aimed at better understanding and identifying the ways in which teachers support student reasoning when provided with conceptually rich tasks. This study resulted in the Teacher…

Mathematical literacy (ML) is considered central to the application of mathematical knowledge in everyday life and thus is found in many comparative international educational standards. However, there exists barely any evidence about predictors and outcomes of ML having a lasting effect on achievement in nonmathematical domains. We drew on a large…

STEM integration holds significant promise for supporting students in making connections among ideas and ways of thinking that might otherwise remain "siloed." Nevertheless, activities that integrate disciplines can present challenges to learners. In particular, they can require students to shift epistemological framing, demands that can…

We studied developmental trends in 5 important reasoning tasks that are critical components of the operational definition of rational thinking. The tasks measured denominator neglect, belief bias, base rate sensitivity, resistance to framing, and the tendency toward otherside thinking. In addition to age, we examined 2 other individual difference…

Empirical arguments rely on examples without necessarily addressing all cases. Students should be skeptical of empirical evidence and should seek more secure arguments for generalizations, such as those that explain why a generalization is true for all cases. Generalizing on the basis of patterns in data is an important mathematical practice;…

Ingroup preferences when deciding who to include in 2 distinct intergroup contexts, gender and school affiliation, were investigated. Children and adolescents, in the 4th (9-10 years) and 8th (13-14 years) grades, chose between including someone in their group who shared their group norm (moral or conventional) or who shared their group membership…

What are the characteristics leading teachers to nominate gifted students in Spain? To answer this question, several demographic (i.e., gender, grade) and psychological (i.e., multiple intelligences, emotional intelligence, intellectual aptitude, and divergent thinking) characteristics of 563 secondary students nominated as gifted by their…

This study explores the impact of working with online learning activities of linear growing patterns (CLIPS) on students transitioning into Grade 9. Fifty students were interviewed about their understanding of linear growing patterns. Twenty-five students had participated in a study involving an experimental instructional approach that emphasized…