Development of a Mechanics Reasoning Inventory

Strategic knowledge is required to appropriately organize procedures and concepts to solve problems. We are developing a standardized instrument assessing strategic knowledge in the domain of introductory mechanics. This instrument is inspired in part by Lawson's Classroom Test of Scientific Reasoning and Van Domelen's Problem Decomposition Diagnostic. The predictive validity of the instrument has been suggested by preliminary studies showing significant correlation with performance on final exams administered in introductory mechanics courses at the Massachusetts Institute of Technology and the Georgia Institute of Technology. In order to study the validity of the content from the student's perspective, we have administered the instrument in free-response format to 40 students enrolled in calculus-based introductory mechanics at the University of Wisconsin-Platteville. This procedure has the additional advantage of improving the construct validity of the inventory, since student responses suggest effective distractors for the multiple-choice form of the inventory.National Science Foundation (U.S.) (PHY-0757931)National Science Foundation (U.S.) (DUE-1044294)National Institutes of Health (U.S.) (1-RC1-RR028302-01

Toward an Integrated Online Learning Environment

We are building in LON-CAPA an integrated learning environment that will enable the development, dissemination and evaluation of PER-based material. This environment features a collection of multi-level research-based homework sets organized by topic and cognitive complexity. These sets are associated with learning modules that contain very short exposition of the content supplemented by integrated open-access videos, worked examples, simulations, and tutorials (some from ANDES). To assess students' performance accurately with respect to a system-wide standard, we plan to implement Item Response Theory. Together with other PER assessments and purposeful solicitation of student feedback, this will allow us to measure and improve the efficacy of various research-based materials, while getting insights into teaching and learning.National Science Foundation (U.S.) (Grant 0757931)National Institutes of Health (U.S.) (Grant # 1RC1RR028302-01

Improved Student Performance In Electricity And Magnetism Following Prior MAPS Instruction In Mechanics

We examine the performance of a group of students in Introductory Electricity and Magnetism following a ReView course in Introductory Mechanics focusing on problem solving employing the Modeling Applied to Problem Solving (MAPS) pedagogy[1]. The group consists of students who received a D in the fall Mechanics course (8.01) and were given the chance to attend the ReView course and take a final retest. Improvement to a passing grade was qualification for the Electricity and Magnetism course (8.02) in the spring. The ReView course was conducted twice—during January 2009 and January 2010. As a control, we took a group of students with similar z-scores in 8.01 in Fall 2007 that were not offered the ReView course. We show that the ReView students perform ~0.7 standard deviations better than the control group (p~0.002) and ~0.5 standard deviations better than what is expected based on their performance in 8.01(p ~0.001).National Science Foundation (U.S.) (NSF grant # 0757931)National Institutes of Health (U.S.) (NIH grant # 1RC1RR028302-01

Importancia de la batimetría de las planicies basales en la propagación de tsunamis transoceánicos

The initial form of a tsunami originated by an homogeneous seismic source consists on a simple wave front. While the tsunami propagates in deep water, this simple form suffers several modifications by the tsunami's interaction with the ocean basin's bathymetry. When the tsunami climbs the continental slope, it suffers more modifications due to the bathymetry and topography of the coastal region. The manner in which these local features modify the tsunami's form depends on the tsunami's form itself, i.e., different tsunamis arriving at the same location do not have the same form, though resemblances can be identified among them, and also among the same tsunami arriving to different regions. In this paper the importance that these modifications on the tsunami's form acquires when it approaches to the coast, is identified for the arrival of the Alaska 1964's tsunami to Hilo Bay in Hawaii and of the Indonesia 2004 and 2005's tsunamis to Colombo in Sri Lanka

Modeling applied to problem solving

We describe a modeling approach to help students learn expert problem solving. Models are used to present and hierarchically organize the syllabus content and apply it to problem solving, but students do not develop and validate their own Models through guided discovery. Instead, students classify problems under the appropriate instructor‐generated Model by selecting a system to consider and describing the interactions that are relevant to that system. We believe that this explicit System, Interactions and Model (S.I.M.) problem modeling strategy represents a key simplification and clarification of the widely disseminated modeling approach originated by Hestenes and collaborators. Our narrower focus allows modeling physics to be integrated into (as opposed to replacing) a typical introductory college mechanics course, while preserving the emphasis on understanding systems and interactions that is the essence of modeling. We have employed the approach in a three‐week review course for MIT freshmen who received a D in the fall mechanics course with very encouraging results.National Science Foundation (U.S.

What do Seniors Remember From Freshman Physics?

We have given a group of 56 MIT seniors who took mechanics as freshmen a written test similar to the final exam they took in their freshman course, plus the Mechanics Baseline Test (MBT) and Colorado Learning Attitudes about Science Survey (C‐LASS) standard instruments. Students in majors unrelated to physics scored 60% lower on the written analytic part of the final than they did as freshmen. The mean score of all students on conceptual multiple choice questions included on the final also declined by about 60% relative to the scores of freshmen. The mean score of all participants on the MBT was insignificantly changed from the posttest taken as freshmen. More specifically, however, the students’ performance on 9 of the 26 MBT items (with 6 of the 9 involving graphical kinematics) represents a gain over their freshman pretest score (a normalized gain of about 70%, double the gain achieved in the freshman course alone), while their performance on the remaining 17 questions is best characterized as a loss of approximately 50% of the material learned in the freshman course. Attitudinal survey results indicate that almost half the seniors feel the specific mechanics course content is unlikely to be useful to them, a significant majority (75–85%) feel that physics does teach valuable skills, and an overwhelming majority believe that mechanics should remain a required course at MIT.National Science Foundation (U.S.

When students can choose easy, medium, or hard homework problems

We investigate student-chosen, multi-level homework in our Integrated Learning Environment for Mechanics [1] built using the LON-CAPA [2] open-source learning system. Multi-level refers to problems categorized as easy, medium, and hard. Problem levels were determined a priori based on the knowledge needed to solve them [3]. We analyze these problems using three measures: time-per-problem, LON-CAPA difficulty, and item difficulty measured by item response theory. Our analysis of student behavior in this environment suggests that time-per-problem is strongly dependent on problem category, unlike either score-based measures. We also found trends in student choice of problems, overall effort, and efficiency across the student population. Allowing students choice in problem solving seems to improve their motivation; 70% of students worked additional problems for which no credit was given.National Science Foundation (U.S.) (Grant PHY-0757931)National Science Foundation (U.S.) (Grant DUE-1044294

What Else (Besides the Syllabus) Should Students Learn in Introductory Physics?

We have surveyed what various groups of instructors and students think students should learn in introductory physics. We started with a Delphi Study based on interviews with experts, then developed orthogonal responses to “what should we teach non‐physics majors besides the current syllabus topics?” AAPT attendees, atomic researchers, and PERC08 attendees were asked for their selections. All instructors rated “sense‐making of the answer” very highly and expert problem solving highly. PERers favored epistemology over problem solving, and atomic researchers “physics comes from a few principles.” Students at three colleges had preferences anti‐aligned with their teachers, preferring more modern topics, and the relationship of physics to everyday life and also to society (the only choice with instructor agreement), but not problem solving or sense‐making. Conclusion #1: we must show students how old physics is relevant to their world. Conclusion #2: significant course reform must start by reaching consensus on what to teach and how to hold students’ interest (then discuss techniques to teach it).National Science Foundation (U.S.) (NSF grant PHY-0757931

Determination of the availability of payment for conservation and improvement activities of wetlands ecosystem of the Huaraz City, Peru

Universidad Nacional Agraria La Molina. Facultad de Economía y Planificación. Departamento Académico de Economía y PlanificaciónEl Método de Valoración Contingente (MVC) fue utilizado con el propósito de determinar la intención de pago (IDP) de los ciudadanos en la ciudad de Huaraz - Perú (Región Ancash) con el fin de estimar un financiamiento para subsidiar el diseño e implementación de las actividades de conservación y restauración de un ecosistema de humedales. Para estimar la IDP, se usó el modelo probabilístico LOGIT; el cual es base de las proposiciones teóricas de Bishop-Heberlein. Los resultados indicaron que las variables más influenciables en la (IDP), son una serie de variables de “apreciación” (de los ciudadanos) respecto a la importancia ecológica de los humedales en la región. Sin embargo, las variables socioeconómicas, como los ingresos, la edad, educación, etc., no fueron muy significativos en explicar la variación en la intención de pago. El mejor indicador estadístico para medir la IDP fue la media, que se estimó al $1.05 USD/familia/mes, revelando que la Región Ancash (Perú) podría erigirse anualmente por un estimado de$312,266 USD. Una importante conclusión es que la valoración económica es la llave para diseñar e implementar actividades de conservación y mejoramiento de los humedales, este sería el comienzo de un proceso que terminaría exitosamente si son completados algunos escalones pendientes.Contingent Valuation Method (CVM) was used with the purpose of determining the willingness to pay (WTP) of the citizens of Huaraz city - Peru (Ancash Region) in order to estimate a financial to subsidize the design and implementation of conservation and restoration activities of the wetland ecosystem. To estimate the WTP, a LOGIT probabilistic model was use; which is base on the theoretical proposal of Bishop-Heberlein. Results indicate that the most influential variables in the WTP, are a set of variables of "appreciation" (of te citizen´s) regarding the ecological importance of the wetlands in their region. However, socioeconomic variables, such as income, age, education, etc., were not significant in explaining the WTP variation. The best statistical indicator for measuring the WTP was the median, which was estimated at $1.05 USD/family/month, revealing that in Ancash region (Peru) it could raise annually by an estimated of$312,266 USD. An important conclusion is that economic valuation is key to design and implement activities of conservation and improvement of the wetlands, this being the beginning of a process that will end successfully if some remaining steps are completed

A new subspecies of Black and Yellow Silky Flycatcher, Phainoptila melanoxantha^

in Costa Rica. In some middle and highlands the abrupt topography delayed the complete destruction of mon-UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí