Matching Items (9)
Filtering by
- All Subjects: science education
- Creators: Semken, Steven
Description
Science, Technology, Engineering & Mathematics (STEM) careers have been touted as critical to the success of our nation and also provide important opportunities for access and equity of underrepresented minorities (URM's). Community colleges serve a diverse population and a large number of undergraduates currently enrolled in college, they are well situated to help address the increasing STEM workforce demands. Geoscience is a discipline that draws great interest, but has very low representation of URM's as majors. What factors influence a student's decision to major in the geosciences and are community college students different from research universities in what factors influence these decisions? Through a survey-design mixed with classroom observations, structural equation model was employed to predict a student's intent to persist in introductory geology based on student expectancy for success in their geology class, math self-concept, and interest in the content. A measure of classroom pedagogy was also used to determine if instructor played a role in predicting student intent to persist. The targeted population was introductory geology students participating in the Geoscience Affective Research NETwork (GARNET) project, a national sampling of students in enrolled in introductory geology courses. Results from SEM analysis indicated that interest was the primary predictor in a students intent to persist in the geosciences for both community college and research university students. In addition, self-efficacy appeared to be mediated by interest within these models. Classroom pedagogy impacted how much interest was needed to predict intent to persist, in which as classrooms became more student centered, less interest was required to predict intent to persist. Lastly, math self-concept did not predict student intent to persist in the geosciences, however, it did share variance with self-efficacy and control of learning beliefs, indicating it may play a moderating effect on student interest and self-efficacy. Implications of this work are that while community college students and research university students are different in demographics and content preparation, student-centered instruction continues to be the best way to support student's interest in the sciences. Future work includes examining how math self-concept may play a role in longitudinal persistence in the geosciences.
ContributorsKraft, Katrien J. van der Hoeven (Author) / Husman, Jenefer (Thesis advisor) / Semken, Steven (Thesis advisor) / Baker, Dale R. (Committee member) / McConnell, David (Committee member) / Arizona State University (Publisher)
Created2014
Description
This dissertation is presented in two sections. First, I explore two methods of using stable isotope analysis to trace environmental and biogeochemical processes. Second, I present two related studies investigating student understanding of the biogeochemical concepts that underlie part one. Fe and Hg are each biogeochemically important elements in their own way. Fe is a critical nutrient for phytoplankton, while Hg is detrimental to nearly all forms of life. Fe is often a limiting factor in marine phytoplankton growth. The largest source, by mass, of Fe to the open ocean is windblown mineral dust, but other more soluble sources are more bioavailable. To look for evidence of these non-soil dust sources of Fe to the open ocean, I measured the isotopic composition of aerosol samples collected on Bermuda. I found clear evidence in the fine size fraction of a non-soil dust Fe source, which I conclude is most likely from biomass burning. Widespread adoption of compact fluorescent lamps (CFL) has increased their importance as a source of environmental Hg. Isotope analysis would be a useful tool in quantifying this impact if the isotopic composition of Hg from CFL were known. My measurements show that CFL-Hg is isotopically fractionated, in a unique pattern, during normal operation. This fractionation is large and has a distinctive, mass-independent signature, such that CFL Hg can be uniquely identified from other sources. Misconceptions research in geology has been a very active area of research, but student thinking regarding the related field of biogeochemistry has not yet been studied in detail. From interviews with 40 undergraduates, I identified over 150 specific misconceptions. I also designed a multiple-choice survey (concept inventory) to measure understanding of these same biogeochemistry concepts. I present statistical evidence, based on the Rasch model, for the reliability and validity of this instrument. This instrument will allow teachers and researchers to easily quantify learning outcomes in biogeochemistry and will complement existing concept inventories in geology, chemistry, and biology.
ContributorsMead, Chris (Author) / Anbar, Ariel (Thesis advisor) / Semken, Steven (Committee member) / Shock, Everett (Committee member) / Herckes, Pierre (Committee member) / Hartnett, Hilairy (Committee member) / Arizona State University (Publisher)
Created2014
Description
This is a qualitative study about sources of self-efficacy and roles of assistive technologies (AT) associated with the science, technology, engineering and mathematics (STEM) choice and participation of STEM professionals and graduate students with sensory and orthopedic disabilities. People with disabilities are underrepresented in STEM, which can be traced back along the STEM pipeline to early undergraduate participation in STEM. Little research exists, however, about pathways and factors associated with successful STEM participation for people with disabilities at any point along their trajectories. Eighteen STEM professionals and graduate students with sensory and orthopedic disabilities were interviewed for this study. Sources of self-efficacy were sought from interview transcripts, as were emergent themes associated with the types, uses and roles of AT. Findings suggest that people with sensory and orthopedic disabilities weigh sources of self-efficacy differently from white males without disabilities in STEM and more like other underrepresented minorities in STEM. Social persuasions were most frequently reported and in far more detail than other sources, suggesting that this source may be most impactful in the development of self-efficacy beliefs for this group. Additionally, findings indicate that AT is critical to the successful participation of people with sensory and orthopedic disabilities in STEM at all points along their STEM pathways. Barriers center around issues of access to full engagement in mainstream STEM classrooms and out of school opportunities as well as the impact of ill-informed perceptions about the capabilities of people with disabilities held by parents, teachers and college faculty who can act as gatekeepers along STEM pathways. Gaps in disability specialists' knowledge about STEM-specific assistive technologies, especially at the college level, are also problematic. The prevalence of mainstream public school attendance reported by participants indicates that classroom teachers and disability-related educators have important roles in providing access to STEM mastery experiences as well as providing positive support and high expectations for students with disabilities. STEM and disability-based networks served to provide participants with role models, out of school STEM learning experiences and important long-term social connections in STEM communities.
ContributorsPacheco, Heather A (Author) / Baker, Dale R. (Thesis advisor) / Forouzesh, Mohammed (Committee member) / Pavri, Shireen (Committee member) / Semken, Steven (Committee member) / Arizona State University (Publisher)
Created2014
Description
Conceptual change has been a large part of science education research for several decades due to the fact that it allows teachers to think about what students' preconceptions are and how to change these to the correct scientific conceptions. To have students change their preconceptions teachers need to allow students to confront what they think they know in the presence of the phenomena. Students then collect and analyze evidence pertaining to the phenomena. The goal in the end is for students to reorganize their concepts and change or correct their preconceptions, so that they hold more accurate scientific conceptions. The purpose of this study was to investigate how students' conceptions of the Earth's surface, specifically weathering and erosion, change using the conceptual change framework to guide the instructional decisions. The subjects of the study were a class of 25 seventh grade students. This class received a three-week unit on weathering and erosion that was structured using the conceptual change framework set by Posner, Strike, Hewson, and Gertzog (1982). This framework starts by looking at students' misconceptions, then uses scientific data that students collect to confront their misconceptions. The changes in students' conceptions were measured by a pre concept sketch and post concept sketch. The results of this study showed that the conceptual change framework can modify students' preconceptions of weathering and erosion to correct scientific conceptions. There was statistical significant difference between students' pre concept sketches and post concept sketches scores. After examining the concept sketches, differences were found in how students' concepts had changed from pre to post concept sketch. Further research needs to be done with conceptual change and the geosciences to see if conceptual change is an effective method to use to teach students about the geosciences.
ContributorsTillman, Ashley (Author) / Luft, Julie (Thesis advisor) / Middleton, James (Committee member) / Semken, Steven (Committee member) / Arizona State University (Publisher)
Created2011
Description
Affect is a domain of psychology that includes attitudes, emotions, interests, and values. My own affect influenced the choice of topics for my dissertation. After examining asteroid interiors and the Moon’s thermal evolution, I discuss the role of affect in online science education. I begin with asteroids, which are collections of smaller objects held together by gravity and possibly cohesion. These “rubble-pile” objects may experience the Brazil Nut Effect (BNE). When a collection of particles of similar densities, but of different sizes, is shaken, smaller particles will move parallel to the local gravity vector while larger objects will do the opposite. Thus, when asteroids are shaken by impacts, they may experience the BNE as possibly evidenced by large boulders seen on their surfaces. I found while the BNE is plausible on asteroids, it is confined to only the outer layers. The Moon, which formed with a Lunar Magma Ocean (LMO), is the next topic of this work. The LMO is due to the Moon forming rapidly after a giant impact between the proto-Earth and another planetary body. The first 80% of the LMO solidified rapidly at which point a floatation crust formed and slowed solidification of the remaining LMO. Impact bombardment during this cooling process, while an important component, has not been studied in detail. Impacts considered here are from debris generated during the formation of the Moon. I developed a thermal model that incorporates impacts and find that impacts may have either expedited or delayed LMO solidification. Finally, I return to affect to consider the differences in attitudes towards science between students enrolled in fully-online degree programs and those enrolled in traditional, in-person degree programs. I analyzed pre- and post-course survey data from the online astrobiology course Habitable Worlds. Unlike their traditional program counterparts, students enrolled in online programs started the course with better attitudes towards science and also further changed towards more positive attitudes during the course. Along with important conclusions in three research fields, this work aims to demonstrate the importance of affect in both scientific research and science education.
ContributorsDingatantrige Perera, Jude Viranga (Author) / Asphaug, Erik (Thesis advisor) / Semken, Steven (Thesis advisor) / Anbar, Ariel (Committee member) / Elkins-Tanton, Linda T. (Committee member) / Robinson, Mark (Committee member) / Arizona State University (Publisher)
Created2017
Description
Previous studies have shown that adequate content knowledge is a necessary, but not sufficient, requirement for affective teaching. While legislation requests teachers to be "highly qualified" in a subject area, such as physics, many teachers are frequently asked to teach in an area when they are not certified through a teaching license to do so. This study uses mixed methods to examine the knowledge of beginning physics teachers. Through semi-structured interviews, classroom observations, and concept maps, the pedagogical content knowledge, subject matter knowledge, and practices of three groups of beginning secondary physics teachers were explored. Data were analyzed qualitatively using cases and quantitatively using descriptive statistics and t-tests, the results of which were combined during the interpretation phase of the research process. The study indicated that, over the first two years of teaching, the in-field group of teachers showed stronger physics content knowledge, a consideration for student difficulties with physics topics, and a positive shift in pedagogical content knowledge impacted by working with students, as compared to the rest of the teachers in the study. This research has implications in the development of secondary physics teachers and in the field of physics education research. Specifically, this research has implications in the physics content support for beginning secondary science teachers, the novice/expert research in physics education research, and the pedagogical preparation of undergraduate students, graduate students, and faculty in physics.
ContributorsNeakrase, Jennifer Jean (Author) / Luft, Julie (Thesis advisor) / Semken, Steven (Committee member) / Culbertson, Robert (Committee member) / Green, Samuel (Committee member) / Clark, Douglas (Committee member) / Arizona State University (Publisher)
Created2010
Description
Biology textbooks are everybody's business. In accepting the view that texts are created with specific social goals in mind, I examined 127 twentieth-century high school biology textbooks for representations of animal development. Paragraphs and visual representations were coded and placed in one of four scientific literacy categories: descriptive, investigative, nature of science, and human embryos, technology, and society (HETS). I then interpreted how embryos and fetuses have been socially constructed for students. I also examined the use of Haeckel's embryo drawings to support recapitulation and evolutionary theory. Textbooks revealed that publication of Haeckel's drawings was influenced by evolutionists and anti-evolutionists in the 1930s, 1960s, and the 1990s. Haeckel's embryos continue to persist in textbooks because they "safely" illustrate similarities between embryos and are rarely discussed in enough detail to understand comparative embryology's role in the support of evolution. Certain events coincided with changes in how embryos were presented: (a) the growth of the American Medical Association (AMA) and an increase in birth rates (1950s); (b) the Biological Sciences Curriculum Study (BSCS) and public acceptance of birth control methods (1960s); (c) Roe vs. Wade (1973); (d) in vitro fertilization and Lennart Nilsson's photographs (1970s); (e) prenatal technology and fetocentrism (1980s); and (f) genetic engineering and Science-Technology-Society (STS) curriculum (1980s and 1990s). By the end of the twentieth century, changing conceptions, research practices, and technologies all combined to transform the nature of biological development. Human embryos went from a highly descriptive, static, and private object to that of sometimes contentious public figure. I contend that an ignored source for helping move embryos into the public realm is schoolbooks. Throughout the 1900s, authors and publishers accomplished this by placing biology textbook embryos and fetuses in several different contexts--biological, technological, experimental, moral, social, and legal.
ContributorsWellner, Karen L (Author) / Maienschein, Jane (Thesis advisor) / Ellison, Karin D. (Committee member) / Robert, Jason S. (Committee member) / Arizona State University (Publisher)
Created2010
Description
The goal of the first study was to characterize the Miocene arkosic conglomerate in the Goldfield Mountains to determine the paleocurrent direction and source of the cobbles. This conglomerate is tilted to the northeast and unconformably overlies Proterozoic basement. Imbrication measurements are scattered but suggest the direction of paleoflow was toward the northwest and northeast, which suggests the cobbles were sourced from the southeast and southwest. The abundance of Dripping Spring Quartzite and the presence of Barnes Conglomerate in the cobbles, suggests an Apache Group source. In addition, south-southeast of the map area, there are several rock units composed of the same material as cobbles within the arkosic conglomerate. The arkosic conglomerate was likely deposited during onset of mid-Cenozoic extension, where the resulting highlands could provide a nearby source for the cobbles. This nearby source is interpreted to be south-southeast of the study area. A second study examined the effectiveness of course reform conducted on an introductory undergraduate course sequence. Questions of this study included: (1) How does the curriculum cater to a student population with diverse goals? (2) How do reformed courses add educational value as perceived by the student? (3) How does the redesigned curriculum and the instructional strategies, as implemented, address the goals of the reform?
The curriculum addressed the goals of the reform by (1) creating more opportunities for students to gain the skills relevant to their future goals, (2) having students utilize big data to make observations, interpretations, and predictions, (3) engaging students in scientific collaboration through group work and discussion, (4) giving students the opportunity to utilize computer programs that apply across various subjects and fields (i.e. Excel, MS Word, ArcGIS), and (5) requiring students to conduct original research to solve a problem and present their results orally and in written form. These redesign efforts were successful in meeting the objectives, and majority of the student participants reported one or more of the reformed experiences were valuable to their education and future goals. An understanding of teaching methods and educational values held by undergraduate students within the School of Earth and Space Exploration can be adapted and applied across subjects.
ContributorsAccetta, Danielle (Author) / Reynolds, Stephen J (Thesis advisor) / Johnson, Julia K (Committee member) / Semken, Steven (Committee member) / Arizona State University (Publisher)
Created2021
Description
Ethnogeology is the scientific study of human relationships with the Earth as a system, typically conducted within the context of a specific culture. Indigenous or historically resident people may perceive local places differently from outside observers trained in the Western tradition. Ethnogeologic knowledge includes traditional indigenous knowledge (alternatively referred to as traditional ecological knowledge or TEK), which exceeds the boundaries of non-Indigenous ideas of physical characteristics of the world, tends to be more holistic, and is culturally framed. In this ethnogeological study, I have implemented several methods of participatory rapid assessment (PRA) from the discipline of field ethnography to collect culturally framed geological knowledge, as well to measure the authenticity of the knowledge collected. I constructed a cultural consensus model (CCM) about karst as a domain of knowledge. The study area is located in the karst physiographic region of the Caribbean countries of the Dominican Republic (DR) and Puerto Rico (PR). Ethnogeological data collected and analyzed using CCM satisfied the requirements of a model where I have found statistically significance among participant’s agreement and competence values. Analysis of the competence means in the population of DR and PR results in p < 0.05 validating the methods adapted for this study. I discuss the CCM for the domain of karst (in its majority) that is shared among consultants in the countries of PR and the DR that is in the form of metaphors and other forms of culturally framed descriptions. This work continuing insufficient representation of minority groups such as Indigenous people, Native Americans, Alaska Natives, and Hispanic/Latinxs in the Earth Sciences.
ContributorsGarcia, Angel Antonio (Author) / Semken, Steven (Thesis advisor) / Brandt, Elizabeth, (Committee member) / Shock, Everett (Committee member) / Bowman, Catherine (Committee member) / Anbar, Ariel (Committee member) / Arizona State University (Publisher)
Created2018