With millions invested in educational technology, what is its impact on student achievement and engagement? This question formed the basis for a review of the current literature on the impact of iPads and other instructional technology on student academic growth and motivation in public schools. The research supports technology’s positive impact on student achievement and engagement, but more research is needed in order to better understand how iPad use impacts students in the early elementary mathematics classroom. This dissertation study examines the effects of an iPad-based math intervention, as compared to a traditional paper-pencil approach, on second graders’ achievement and engagement in mathematics. The students were assigned to treatment and control groups in matched pairs based on sex and pre-test scores. Then students engaged in a four-week math intervention, using either the iPad or paper-pencil. At the end of each intervention, students completed quantitative posttests given by their classroom teachers. Students then switched treatment and control groups for a second four-week math intervention. Quantitative pre-post assessments include Bridges math unit tests, easyCBM math tests, and a Likert-scale engagement measure. After the two interventions were completed, qualitative focus group data were collected from the teachers involved in the study, giving a more complete view of student engagement. With finite intervention time and resources, schools need to know how to best improve student achievement and engagement in mathematics. This study fills a documented research gap and will help inform school decisions regarding instructional technology in the early elementary math classroom.

<p dir="ltr">To better predict volcanic behavior, we must understand the processes that occur in the underlying magma reservoirs. This thesis contains three chapters that work together to better understand processes that occur in sub-volcanic reservoirs. Chapter 2 is a study of an ancient, coupled volcanic-plutonic system to determine the link between the volcanic and plutonic parts of the system. The IXL-Job Canyon magmatic system is an ~28-29 Ma system, which shows a rapid transition between eruption of tuffs and lava flows to construction of an upper-crustal pluton, via incremental emplacement. The system experienced an eruptive hiatus during and after pluton construction, until the eruption of a newly identified, younger, rhyolitic tuff. This work suggests that the absence of volcanic activity at the surface does not mean that the underlying magmatic plumbing system is also inactive. Chapter 3 compiles existing U-Pb zircon ID-TIMS data for upper-crustal, silicic magmatic systems, to determine the size and frequency of magmatic increments that accumulate to build up these systems. A Monte Carlo-based model is used to investigate the underlying distributions of the increment size and time between increments, and results in sizes and inter-event times that follow an exponential distribution. This work helps guide how we can try to introduce broadly generalizable complexities into thermal models of such systems. Chapter 4 focuses on organic interferences, a common issue that impacts the speed and quality of U-Pb and Pb-Pb data collected on TIMS instruments. We share two techniques used at the Purdue Radiogenic Isotope Geology Lab to first reduce and then avoid any residual organic interferences. These techniques help shorten analytical times, increasing throughput, and provide a means to reduce uncertainties on our measurements, since the presence of organic interferences can bias and increase the uncertainties on U-Pb dates.</p>