Medición informal del p-valor mediante simulación

Existe un creciente reconocimiento de la importancia de desarrollar el razonamiento inferencial informal (RII) antes de aprender los conceptos formalmente. No obstante todavía hay poca investigación sobre su desarrollo en el aula en el nivel bachillerato (15-18 años). En situaciones informales, la principal dificultad es medir el p-valor de un estadístico, debido que no se tiene la noción de distribución muestral de forma natural. En el presente estudio se analiza el razonamiento de estudiantes de bachillerato para medir el p-valor de un estadístico al usar una aplicación dinámica que crea una distribución muestral empírica mediante la simulación computarizada. Se encuentra que la mayoría de los estudiantes miden el p-valor adecuadamente con ayuda de la simulación, lo que representa un cambio significativo en el RII

El aprendizaje desde la instrucción : la evolución de las estrategias personales en tareas de proporcionalidad numérica

This study examines the personal strategies evolution used by students in numerical proportionality task solving during instruction. The analysis of a sequence of video/audiotaped lessons allowed the observation of the process of cognitive construction by students in the classroom. The «local» effectiveness of intuitive strategies is considered a phase in the construction of more general strategies

Program development using abstract interpretation (and the ciao system preprocessor)

The technique of Abstract Interpretation has allowed the development of very sophisticated global program analyses which are at the same time provably correct and practical. We present in a tutorial fashion a novel program development framework which uses abstract interpretation as a fundamental tool. The framework uses modular, incremental abstract interpretation to obtain information about the program. This information is used to validate programs, to detect bugs with respect to partial specifications written using assertions (in the program itself and/or in system librarles), to genérate and simplify run-time tests, and to perform high-level program transformations such as múltiple abstract specialization, parallelization, and resource usage control, all in a provably correct way. In the case of validation and debugging, the assertions can refer to a variety of program points such as procedure entry, procedure exit, points within procedures, or global computations. The system can reason with much richer information than, for example, traditional types. This includes data structure shape (including pointer sharing), bounds on data structure sizes, and other operational variable instantiation properties, as well as procedure-level properties such as determinacy, termination, non-failure, and bounds on resource consumption (time or space cost). CiaoPP, the preprocessor of the Ciao multi-paradigm programming system, which implements the described functionality, will be used to illustrate the fundamental ideas

Wetland restoration and nitrate reduction: the example of the periurban wetland of Vitoria-Gasteiz (Basque Country, North Spain)

Changes in land use and agricultural intensification caused wetlands on the quaternary aquifer of Vitoria-Gasteiz (Basque Country) to disappear some years ago and nitrate concentration in groundwaters increased very quickly. The Basque Government recently declared the East Sector of this aquifer a Vulnerable Zone according to the 91/676/CEE European Directive. Recently, the wetlands have been restored through the closure of the main drainage ditches, the consequent elevation of the water table and the abondonment of agricultural practices near the wetlands. This is the case of the Zurbano wetland. Restoration has allowed the recovery of its biogeochemical function, which has reduced nitrate concentrations in waters. Nitrate concentrations which exceed 50 mg l–1 in groundwaters entering into the wetland are less than 10 mg l–1 at the outlet. Conditions in the wetland are conducive to the loss of nitrates: organic matter rich wetted soils, clay presence allowing a local semiconfined flow and very low hydraulic gradient. Water quality monitoring at several points around the wetland showed the processes involved in nitrate loss, although some aspects still remain unresolved. However, during storm events, the wetland effectively reduces the nitrate concentration entering the Alegria River, the most important river on the quaternary aquifer

Evidences of evanescent Bloch waves in Phononic Crystals

We show both experimentally and theoretically the evanescent behaviour of modes in the Band Gap (BG) of finite Phononic Crystal (PC). Based on experimental and numerical data we obtain the imaginary part of the wave vector in good agreement with the complex band structures obtained by the Extended Plane Wave Expansion (EPWE). The calculated and measured acoustic field of a localized mode out of the point defect inside the PC presents also evanescent behaviour. The correct understanding of evanescent modes is fundamental for designing narrow filters and wave guides based on Phononic Crystals with defects.Comment: 8 pages, 3 figure

El conocimiento acerca de las matemáticas y las prácticas de enseñanza

The individual and contextual influences that two periods of school experience have over the way in which two prospective teachers build their personal view of Mathematics and its teaching are studied. In particular, the important role played by the perceived knowledge of the subject matter knowledge is shown. Also, the strategies used in trying to give coherence and meaning to the experimented changes are discussed

The CIAO multiparadigm compiler and system: A progress report

Abstract is not available

Introducción de las técnicas de modelización para el estudio de la física y de las matemáticas en los primeros cursos de las carreras técnicas

In this article we present a program of interdisciplinary practices for a first engineering course. We followed this program during the course 1996-1997, and we give several examples of the kind of exercises that we used. We also present some remarks and conclusions that we have achieved in our experience. Our purpose is to introduce a teaching strategy for Mathematics and Physics at the University level

More than a magazine: exploring the links between lads’ mags, rape myth acceptance and rape proclivity

Exposure to some magazines aimed at young male readers – lads’ mags – has recently been associated with behaviors and attitudes that are derogatory towards women, including sexual violence. In the present study, a group of Spanish adult men were exposed to the covers of a lads’ mag while a second group was exposed to the covers of a neutral magazine. Results showed that, compared to participants in the second group, participants who were exposed to covers of lads’ mags who also showed high rape myth acceptance (RMA) and legitimized the consumption of such magazines reported higher rape proclivity in a hypothetical situation. These findings suggest the need to further explore the possible detrimental effects of some sexualized media that are widely accepted in many Western countries