Julie C. Libarkin

Rise of the Andes

The surface uplift of mountain belts is generally assumed to reflect progressive shortening and crustal thickening, leading to their gradual rise. Recent studies of the Andes indicate that their elevation remained relatively stable for long periods (tens of millions of years), separated by rapid (1 to 4 million years) changes of 1.5 kilometers or more. Periodic punctuated surface uplift of mountain belts probably reflects the rapid removal of unstable, dense lower lithosphere after long-term thickening of the crust and lithospheric mantle.

College Student Conceptions of Geological Time and the Disconnect between Ordering and Scale

College student conceptions of the scale of geologic time and the relationships between time and geological or biological events were evaluated through interviews, open-ended questionnaires, and student generated timelines collected from four institutions. Our data indicate students hold a number of alternative conceptions about the Earths formation and the appearance of life, and these ideas are remarkably consistent across institutions. Transferability of these findings was evaluated via comparison with Geoscience Concept Inventory questions related to geologic time collected from 43 institutions nationwide. Detailed evaluation of student timelines reveals a notable disconnect between the relative relationships between the age of the Earth, the time required for the origin of the first life forms (prokaryotes), and the evolution of dinosaurs and humans. Students generally placed these events in the correct relative order, but had a poor understanding of the scale of time between events. Intriguingly, timelines can be mapped onto ternary diagrams, and the relationship between ternary diagram zoning and specific ideas of geologic time is explored. We found that some students, for example those with a young Earth perspective, map onto specific conceptual zones on ternary diagrams.

A Test of the Circumvention-of-Limits Hypothesis in Scientific Problem Solving: The Case of Geological Bedrock Mapping

Sources of individual differences in scientific problem solving were investigated. Participants representing a wide range of experience in geology completed tests of visuospatial ability and geological knowledge, and performed a geological bedrock mapping task, in which they attempted to infer the geological structure of an area in the Tobacco Root Mountains of Montana. A Visuospatial Ability × Geological Knowledge interaction was found, such that visuospatial ability positively predicted mapping performance at low, but not high, levels of geological knowledge. This finding suggests that high levels of domain knowledge may sometimes enable circumvention of performance limitations associated with cognitive abilities.

Ontology and the Teaching of Earth System Science

Student ontological level is an important consideration for faculty interested in teaching Earth System Science. Interviews with 61 students enrolled in entry-level geology courses at two institutions reveal that very few students exhibit Process or Systems ontologies. Earth Systems Science instruction generally assumes that students are thinking about processes and systems, although this study suggests that students predominantly understand that changes occur on Earth without either 1) a concrete acceptance that these changes result from a cause, or 2) an explanation for these causes beyond scientific terms such as “subduction”. This has critical implications for teaching Earth System Science, and suggests that activities that can help college students develop Process and Systems ontologies need to be developed and evaluated.

Alternative Conceptions of Plate Tectonics Held by Nonscience Undergraduates

Abstract The theory of plate tectonics is the conceptual model through which most dynamic processes on Earth are understood. A solid understanding of the basic tenets of this theory is crucial in developing a scientifically literate public and future geoscientists. The size of plates and scale of tectonic processes are inherently unobservable, necessitating the use of images and models in instruction. To explore plate tectonics conceptions held by undergraduates, we designed and administered a postinstruction survey instrument centered on a common schematic representation of plate tectonics. We report results from a sample of n =60 nongeoscience majors enrolled in five different introductory Earth-science courses taught at a major research university and a community college. Students held a number of alternative conceptions associated with terminology, plate motion, and plate-related subsurface melting. We also note that some aspects of figures commonly used to teach plate tectonics are problematic for students and may actually result in reinforcement of alternative conceptions. Further work at both the K–12 and college levels directed at innovative approaches to address student conceptions regarding plate tectonics, including designing images that support key scientific messages, is needed. This research can inform curriculum development for entry-level geoscience courses as well as the use of images to convey complex science.

An Empirical Methodology for Investigating Geocognition in the Field

The investigation of how geologists engage in field mapping, including strategies and behaviors, is an open area of research with significant potential for identifying connections to best instructional practices. While study of experts in an array of disciplines has yielded general conclusions about the nature of expertise, the consideration of geoscience experts, especially in authentic settings, is virtually unstudied. Field mapping involves a complex interplay between the individual mapper and the natural environment. Both cognition and behavior influence the observations and interpretations that ultimately yield the map, a representation of the natural world. We set out to establish a methodology, adapted from existing studies of expertise, that would allow us to document cognitive and behavioral processes involved in situated map-making and generate preliminary insights into expert-novice differences in mapping behavior and cognition. We present here a theoretically–driven, mixed methods methodology, and suggest that navigation coupled with field artifact and audio data provide the richest and most meaningful insights into geocognition in the field.

Revisiting the Geoscience Concept Inventory: A call to the community

The use of concept inventories in science and engineering has fundamentally changed the nature of instructional assessment. Nearly a decade ago, we set out to establish a baseline for widespread and integrated assessment of entry-level geoscience courses. The result was the first Geoscience Concept Inventory (GCI v.1.0). We are now retiring GCI v.1.0 and rebuilding the GCI as a more community-based, comprehensive, and effective instrument. We are doing this in the hopes that GCI users, many of whom have expressed a need for a revised and expanded instrument, and the geoscience community at large will view it as a springboard for collaborative action and engagement. If we work together as collaborators, the geosciences have the potential to evaluate learning across our community and over time. INTRODUCTION The Geoscience Concept Inventory (GCI; Fig. 1) was developed to diagnose conceptual understanding and assess learning in entry-level geoscience courses. The GCI has become a staple in many classroom-based research studies, is being revised for use in pre-college settings, and has been shown to discriminate between experts and novices. Although a valuable research tool, the GCI is in need of an expansion that can only be accomplished by a community of geoscientists and educators working together. This paper is a call for that collaboration. The GCI holds a unique place in the concept inventory world for several reasons. First, the GCI is the only concept inventory to generate a bank of correlated concept inventory questions for higher education science (Libarkin and Anderson, 2006). Through this correlation, users of the GCI can create course-specific subtests rather than being tied to a single set of questions. Second, the GCI contains single response, two-tier, and multiple-response multiple-choice questions. Two-tier questions offer added insight into student thinking by requesting an explanation for student responses (Treagust, 1988). Multipleresponse questions, essentially a set of true/false items, are generally more difficult than typical single-response items and are cognitively similar to free response questions, offering deeper insight into cognition (Kubinger and Gottschall, 2007). Third, GCI questions were developed from ideas that both experts and novices found important for entry-level geoscience courses. A review of textbooks provided initial ideas about important concepts for inclusion on the GCI, while open-ended interviews with students provided additional topics (Libarkin and Anderson, 2005). For example, in-depth interviews suggest that students conflate gravity and magnetism and inflate the importance of magnetic fields on the movement of large objects. Addressing this mixing and mis-scaling is important for student understanding of geomagnetism and its effects, a discovery that only became apparent after considering the student perspective. THE NEED TO REVISE AND EXPAND THE GCI AS A COMMUNITY The original GCI questions were piloted with up to 5,000 students enrolled at >40 institutions nationwide, with the current version in use by >200 faculty and researchers. The GCI has been used to estimate learning in geoscience courses, including evaluation of specific instructional approaches (e.g., Kortz et al., 2008) and analysis of learning (e.g., Petcovic and Ruhf, 2008). In ongoing work, GCI scores have been shown to correlate strongly with geological mapping ability. This suggests that the GCI, a measure of very foundational knowledge, can be used as a skills measure to predict performance on an expert task. While we are encouraged that GCI v.1.0 was useful in these studies, we acknowledge that the instrument ingrains our own biases and limitations. As many of our colleagues have stated, the GCI is both an effective instrument for gauging learning in entry-level geoscience courses and a test in need of revision. The diversity of geoscience courses at all levels should be reflected in the assessment instruments used to evaluate learning nationwide. Expansion to more complex, wider ranging questions will allow replicable assessment in advanced courses and across geoscience programs. A critical need for questions targeted toward upper-level courses requires community GSA Today, v. 21, no. 8, doi: 10.1130/G110GW.1 *libarkin@msu.edu Revisiting the Geoscience Concept Inventory: A call to the community GROUNDWORK T H E G EO LO GI CAL SCIETY OF AM ERIC A Furthering the Inf luence of Earth Science

Factor Analysis of Drawings: Application to college student models of the greenhouse effect

Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance, suggesting that 4 archetype models of the greenhouse effect dominate thinking within this population. Factor scores, indicating the extent to which each students drawing aligned with representative models, were compared to performance on conceptual understanding and attitudes measures, demographics, and non-cognitive features of drawings. Student drawings were also compared to drawings made by scientists to ascertain the extent to which models reflect more sophisticated and accurate models. Results indicate that student and scientist drawings share some similarities, most notably the presence of some features of the most sophisticated non-scientific model held among the study population. Prior knowledge, prior attitudes, gender, and non-cognitive components are also predictive of an individual students model. This work presents a new technique for analyzing drawings, with general implications for the use of drawings in investigating student conceptions.

Conceptions, Cognition, and Change: Student Thinking about the Earth

at all levels hold explanations of natural phenomena that are at odds with scientific ideas. These non-scientific explanations (alternative conceptions, misconceptions, or common-sense beliefs, among other names) are often resistant to change and can persist despite the best efforts of instructors. Students may overprint their alternative conceptions with material taught in the classroom, creating blended conceptions that are still removed from scientific ideas. Other students may simply reject the scientific conception in favor of ideas that have thus far proven adequate. As a consequence, learners may never integrate scientific conceptions into their explanations of the world. Clearly, alternative conceptions can interfere with learning, suggesting that instruction must be carefully designed to address preexisting ideas. Over the past several decades, curriculum developers for both K-12 and college science have addressed the issue of conceptual change, documenting techniques that engender student learning in a number of scientific disciplines. Existing work suggests intriguing links between nontraditional teaching approaches and conceptual change, although uncertainty surrounds the transferability of instructional techniques to all disciplines and age groups. Unraveling the complex relationships between teaching and learning for a specific discipline and group of learners requires both an understanding of common alternative conceptions and valid and reliable methodologies for assessing conceptual change.

Research in Science Education: Threshold Concepts

This article introduces the idea of threshold concepts as a means to better understand student learning and, hence, to develop an enhanced curriculum to facilitate that learning. The debate surrounding threshold concepts is relatively recent and has mainly been focused within other disciplines such as economics, maths and history. Following on from their contributions to a conference in the UK on threshold concepts in geography, earth and environmental sciences, the authors are seeking to open the debate more widely to the geoscience community and thereby begin to develop an understanding of what this new approach to learning means for our subject area.