The concentration in K-12 education on higher-order thinking has diminished the importance of math fact automaticity, which is the ability to deliver a correct answer immediately from long-term memory without impeding the working memory. This quantitative study investigated the influence of automaticity of high school students on their Missouri…

This dissertation is guided by my driving research question: what works for whom in education and why? I examine issues of instruction, assessment, and research approaches that begin to answer this question. Study 1 examines a classroom intervention's child x instruction interactions. Study 2 examines underlying cognitive factors, including…

This study examines how large scale assessments like the Scholastic Aptitude Test (SAT), developed for students proficient in academic English, may not produce reliable and valid outcomes for academically vulnerable students, namely English Language Learners (ELLs). This mixed-methods study was conducted to uncover differences between the old and…

The purpose of this study was to establish the reliability and validity of the construct map for students' conception of equivalence with special emphasis on investigating the impact of structure of equation on students' conception of equivalence. The study examined the role of structure of equations in identifying students' conception of…

The purpose of this study was to examine adult developmental mathematics (ADM) students' knowledge of fraction addition and subtraction as it relates to their demonstrated fraction schemes and ability to disembed in multiplicative contexts with whole numbers. The study was conducted using a mixed methods sequential explanatory design. In the first…

The present study aimed to represent the innovative assessments that support students' learning in STEM education through using the integrative framework for Cognitive Diagnostic Modeling (CDM). This framework is based on three components, cognition, observation, and interpretation (National Research Council, 2001). Specifically, this dissertation…

Though the No Child Left Behind Act of 2001 requires secondary students with Asperger's syndrome (AS) to take high-stakes mathematical tests, many students with AS exhibit weaknesses in mathematical and executive functioning skills. The purpose of this mixed-methods case study was to explore the use of differentiated mathematical strategies with…