Laura Gil

Understanding and Integrating Multiple Science Texts: Summary Tasks are Sometimes Better Than Argument Tasks

One of the major challenges of a knowledge society is that students as well as other citizens must learn to understand and integrate information from multiple textual sources. Still, task and reader characteristics that may facilitate or constrain such intertextual processes are not well understood by researchers. In this study, we compare the effects of summary and argument essay tasks when undergraduates read seven different texts on a particular scientific topic, finding that an instruction to write summaries may lead to better understanding and integration than an instruction to write argument essays. We discuss several possible explanations for this result. We also found that beliefs about the certainty of knowledge in some instances can moderate the effect of task on comprehension performance.

Recording online processes in task-oriented reading with Read&Answer

We present an application to study task-oriented reading processes called Read&Answer. The application mimics paper-and-pencil situations in which a reader interacts with one or more documents to perform a specific task, such as answering questions, writing an essay, or similar activities. Read&Answer presents documents and questions with a mask. The reader unmasks documents and questions so that only a piece of information is available at a time. This way the entire interaction between the reader and the documents on the task is recorded and can be analyzed. We describe Read&Answer and present its applications for research and assessment. Finally, we explain two studies that compare readers’ performance on Read&Answer with students’ reading times and comprehension levels on a paper-and-pencil task, and on a computer task recorded with eye-tracking. The use of Read&Answer produced similar comprehension scores, although it changed the pattern of reading times.

Cation and anion recognition characteristics of open-chain polyamines containing ethylenic and propylenic chains

Abstract The interaction of the polyamines 4,7,10,13-tetraazahexadecane-1,16-diamine (L1) and 4,7,10-triazatridecane-1,13-diamine (L2) with H + , Cu 2+ , Zn 2+ , Co 2+ and the nucleotides ATP, ADP and AMP has been followed by NMR and potentiometric studies performed at 298.1 K in 0.15 mol dm −3 NaClO 4 . The influence of the different sequences of hydrocarbon chains and chelate rings present in the ligands on the values of the protonation constants, the stability of the metal ion complexes as well as in the co-ordination to nucleotides is analysed. The formation of mixed complexes has been investigated for the system Cu 2+ –L1–AMP.

Papel de los procesos metacognitivos en una tarea de pregunta-respuesta con textos escritos

Resumen Este estudio analiza el papel de medidas metacognitivas de monitorización y auto-regulación del proceso de contestar a preguntas de un texto, así como su contribución para explicar las diferencias individuales más allá de la explicación proporcionada por una medida general de comprensión lectora. Estudiantes de secundaria leyeron dos textos y contestaron preguntas, la mitad de las cuales contenía una contradicción interna. La detección de la contradicción fue utilizada para medir la monitorización de la comprensión de las preguntas. Los estudiantes realizaban la tarea en un ordenador que registraba el tiempo y secuencia de lectura, lo que permitió medir procesos de auto-regulación durante la tarea. Los resultados indican que las medidas de monitorización y auto-regulación explican un porcentaje significativo de la varianza de la puntuación total de respuesta a las preguntas más allá de la explicación proporcionada por la medida general de comprensión.

Stability and kinetics of the acid-promoted decomposition of Cu(II) complexes with hexaazacyclophanes: kinetic studies as a probe to detect changes in the coordination mode of the macrocycles

The synthesis, protonation and Cu(II) coordination features of the novel azacyclophane type receptors 2,6,10,13,17,21-hexaza[22]-(2,6)-pyridinophane (L2), 2,6,9,12,15,19-hexaza[20]-(2,6)-pyridinophane (L5) and 2,6,9,12,15,19-hexaza[20]metacyclophane (L6) are presented. The protonation and Cu(II) constants are analysed and compared with the previously reported open-chain polyamines 4,8,11,15-tetrazaoctadecane-1,18-diamine (L1) and 4,7,10,13-tetraazahexadecane-1,16-diamine (L4) and of the cyclophane 2,6,10,13,17,21-hexaaza[22]paracyclophane (L3). All the systems form mono- and dinuclear complexes whose stability and pH range of existence depend on the type of hydrocarbon chains and molecular topology. The effects of the cyclic or open-chain nature and of the presence of the pyridine rings on the protonation and formation of mono- and dinuclear complexes are discussed. Stopped-flow kinetic measurements on the acid-promoted decomposition of the Cu(II) complexes have been carried out for the different systems. With respect to the decomposition of the dinuclear complexes, because the size of the macrocycles forces both metal ions to be close to each other, the release of the first ion occurs within the mixing time of the stopped-flow except for the dinuclear complexes of L2. However, the most interesting kinetic result is the observation of different kinetics of decomposition for the different mononuclear complexes formed by a given ligand. This effect is especially evident for L3 and L6 and indicates a change in the coordination mode of the ligand for the different mononuclear species. Therefore the Cu(II) ion performs a slippage motion through the macrocyclic cavity driven by pH changes. The stopped-flow experiments are an excellent tool to detect these slippage processes that may be present for the complexes with other macrocycles.

On-Line Assessment of Comprehension Processes

In this paper we describe a new version of a former paper-and-pencil standardized comprehension test called Test of Comprehension Processes (Vidal-Abarca, Gilabert, Martínez, & Sellés, 2007). The new version has been adapted to a computer-based environment based on the moving window technique. It can be used to assess comprehension strategies of students from fifth to tenth grades (11- to 16-years-old). Comprehension strategies are registered on-line using reading times and visits to relevant sections of the text during the question-answering process. Data show that the computer-based version draws similar results to those provided by the paper-and-pencil version. In addition, we identify the particular strategies deployed during the question-answering process by high, medium and low comprehenders.

Volumetric behavior of the {CO2 (1) + C2H6 (2)} system in the subcritical (T = 293.15 K), critical, and supercritical (T = 308.15 K) regions.

The volumetric behavior for the {CO2 (1) + C2H6 (2)} system has been studied. Density measurements of {CO2 (1) + C2H6 (2)} binary mixtures at 293.15 and 308.15 K, at several pressures and compositions, and density measurements for infinitely dilute solutions at 304.21 and 308.15 K were carried out using an Anton Paar DMA 512-P vibrating-tube densimeter calibrated with the forced path mechanical calibration model. The mean relative standard deviation of density, s(rho)(r), was estimated to be better than 0.1%, and the uncertainties in temperature and pressure were estimated as +/-0.01 K and +/-0.001 MPa, respectively. In the experimental setup, an uncertainty in the mole fraction of u(x(j)) = +/-0.0015 has been achieved. Other properties related to P-rho-T-x data such as the compressibility factor, Z, excess molar volumes, V(m)(E), and partial molar volumes, V(i) and V(i)(infinity) have been calculated. The volumetric behavior has been compared with literature data and with that obtained from the PC-SAFT EoS rescaled parameters; these parameters have been obtained from our previous experimental values for the critical temperature and pressure of pure compounds. The value for the Krichevskii parameter, A(Kr), was obtained from the experimental density data for infinitely dilute solutions measured in this work, and it has been compared with that obtained from critical properties. Structural properties such as direct and total correlation function integrals and cluster size were calculated using the Krichevskii function concept.

TuinLEC, an intelligent tutoring system to improve reading literacy skills / TuinLEC, un tutor inteligente para mejorar la competencia lectora

Abstract This study describes an intelligent tutoring system to improve reading literacy skills called TuinLEC and it presents the results of its application to a group of sixth grade students. TuinLEC adopts the reading literacy theoretical framework of PISA (Program for International Students Assessment, OECD, 2009). TuinLEC includes eight lessons distributed in two phases, one for modeling and guided practice, and the second for independent practice. TuinLEC interacts with every student and it provides help and feedback for the task in a game-like environment. Half of the students were taught with TuinLEC, whereas the other half served as the control group. Children in both groups were paired according to reading comprehension scores. We measured students’ reading literacy skills after intervention, which showed that the experimental group significantly outperformed the control group. Students who were taught with TuinLEC were also given a questionnaire measuring satisfaction, usability, and self-efficacy; TuinLEC scored positively in all these measurements. We discuss how TuinLEC can improve the reading literacy skills of sixth-graders as well as the contribution of intelligent tutoring systems to instructional interventions.

Hydrogen-ion driven molecular motions in Cu2+-complexes of a ditopic phenanthrolinophane ligand.

One of the first kinetic evaluations of a metal ion interchange between the two coordination sites of a ditopic macrocycle is presented.

Eficacia de tomar notas para integrar información de varios textos

Resumen Este estudio analiza el efecto de tomar notas para integrar información de varios documentos científicos. Estudiantes universitarios leyeron cuatro textos científicos para elaborar un ensayo sobre un tema común a los cuatro textos. La mitad de los estudiantes pudieron tomar notas mientras leían así como usarlas para elaborar el ensayo, mientras la otra mitad no pudieron. La tarea fue realizada en un ordenador de forma que se registró la secuencia de acciones de cada participante. La eficacia de la integración se midió mediante algunos índices de la calidad del ensayo y dos medidas adicionales de aprendizaje. Los resultados indicaron que los alumnos que no tomaron notas aprendieron más que los que las tomaron, aunque escribieron menos ideas textuales en el ensayo. El registro on-line proporcionó evidencias para explicar estos resultados. Finalmente se discuten las limitaciones del estudio así como sus aplicaciones educativas.