The effect that comparing molecular animations of varying accuracy has on students’ submicroscopic explanations
10. Kelly, R. M.; Akaygun, S.; Hansen, S. J. R.; Villalta-Cerdas, A. The effect that comparing molecular animations of varying accuracy has on students’ submicroscopic explanations. Chemical Education Research and Practice, 2017, 18, 582-600.
In this qualitative study, we examined how a group of seventeen first semester General Chemistry students responded when they were shown contrasting molecular animations of a reduction–oxidation (redox) reaction between solid copper and aqueous silver nitrate for which they first viewed a video of the actual experiment. The animations contrasted in that they portrayed different reaction mechanisms for the redox reaction. One animation was scientifically accurate and reflected an electron exchange mechanism, while the other was purposefully inaccurate and represented a physical exchange between the ions. Students were instructed to critique each animation for its fit with the experimental evidence and to ultimately choose the animation that they felt best depicted the molecular level of the chemical reaction. Analyses showed that most students identified that the electron exchange animation was the more scientifically accurate animation; however, approximately half of the students revised their drawings to fit with the inaccurate physical exchange animation. In addition, nearly all students thought that both animations were correct and useful for understanding salient information about the redox reaction. The results indicate that when students are shown contrasting animations of varying accuracy they make errors in deciding how the animations are supported and refuted by the evidence, but the treatment is effective. Contrasting animations promote students to think deeply about how animations fit with experimental evidence and is a promising way to engage students to think deeply about animations.
Assessment of self-explaining effect in a large enrollment general chemistry course
9. Villalta-Cerdas, A.; Sandi-Urena, S. Assessment of self-explaining effect in a large enrollment general chemistry course. Educacion Quimica, 2016, 27(2), 115-125.
Self-explaining refers to the generation of inferences about causal connections between objects and events for one's own consumption. Self-explaining is amongst the practices of science deemed essential for scientific competence; therefore, a valued learning outcome in itself. Nonetheless, generation of authentic explanations is seldom promoted in college science instruction. This work examined the effect of engagement in self-explaining on conceptual understanding of chemistry. Learning and performance tasks were completed individually in the classroom ecology of a large-enrolment General Chemistry course in the US. The study spanned a period of five semesters including pilot-tests and replications. The self-explaining intervention followed a multi-condition comparison design that used performance on a post-test to assess learning. Students were randomly assigned to the following conditions: reviewing a correct explanation, explaining correct or incorrect answers, explaining agreement with answers produced by others, and explaining their own answers. A cohort of students who underwent standard instruction with no intervention and had prepared for formal examination served as reference. The self-explaining cohorts performed better than the reference group, and in one case was the difference statistically significant. Findings suggest that self-explaining activities support students’ conceptual understanding at least as much as instruction. This study contributes evidence for the self-explaining effect and the ICAP hypothesis in a discipline where no evidence is available. Furthermore, it adds to the relatively little work in self-explaining that has explored naturalistic learning environments. This work supports the incorporation of self-explaining activities in the repertoire of instructional practices for General Chemistry.
Self-explaining effect in general chemistry instruction: Eliciting overt categorical behaviours by design
8. Villalta-Cerdas, A.; Sandi-Urena, S. Self-explaining effect in general chemistry instruction: Eliciting overt categorical behaviours by design. Chemical Education Research and Practice, 2014, 15, 530-540.
Self-explaining refers to the generation of inferences about causal connections between objects and events. In science, this may be summarised as making sense of how and why actual or hypothetical phenomena take place. Research findings in educational psychology show that implementing activities that elicit self-explaining improves learning in general and specifically enhances authentic learning in the sciences. Research also suggests that self-explaining influences many aspects of cognition, including acquisition of problem-solving skills and conceptual understanding. Although the evidence that links self-explaining and learning is substantial, most of the research has been conducted in experimental settings. There remains a need for research conducted in the context of real college science learning environments. Working to address that need, the larger project in which this work is embedded studied the following: (a) the effect of different self-explaining tasks on self-explaining behaviour and (b) the effect of engaging in different levels of self-explaining on learning chemistry concepts. The present study used a multi-condition, mixed-method approach to categorise student self-explaining behaviours in response to learning tasks. Students were randomly assigned to conditions that included the following: explaining correct and incorrect answers, explaining agreement with another's answer, and explaining one's own answer for others to use. Textual, individual data was gathered in the classroom ecology of a university, large-enrolment general chemistry course. Findings support an association between the self-explaining tasks and students' self-explaining behaviours. Thoughtful design of learning tasks can effectively elicit engagement in sophisticated self-explaining in natural, large-enrolment college chemistry classroom environments.
Evaluation of Instruction: General Chemistry Students’ Patterns of Use and Contribution to RateMyProfessors.com
7. Villalta-Cerdas, A.; McKeny, P.; Gatlin, T. A.; Sandi-Urena, S. Evaluation of Instruction: General Chemistry Students’ Patterns of Use and Contribution to RateMyProfessors.com. Assessment & Evaluation in Higher Education, 2014, 40(2). 181-198.
RateMyProfessors.com (RMP) is the most popular commercial website to evaluate instructors, and houses a wealth of student-generated information in the form of ratings and reviews. This study investigated whether general chemistry students who use RMP were different from other students, and their reasons to use and contribute to the site. A pool of 398 students were surveyed. The survey gathered demographic information, patterns and frequency of use, and information to characterise participants in terms of their learning/grade orientation. Data analysis included descriptive and inferential statistics and the application of mixture models (latent class analysis and latent profile analysis). There were no significant differences between contributors and non-contributors in terms of gender, major, year status, grade point average, course load, previous chemistry grade and learning/grade orientation. Findings for this sample do not support the common assumption that students use RMP to shop for easy instructors. Instructor helpfulness, clarity and overall rating were reported as important aspects to visit the site. Findings agree with literature reports and support the use of RMP as supplemental data to inform assessment of instruction at the general chemistry programme level. Programmes in other disciplines can adapt the methods presented to assess the suitability of RMP data-sets for similar purposes.
Self-explaining and its Use in College Chemistry Instruction
6. Villalta-Cerdas, A.; Sandi-Urena, S. Self-explaining and its Use in College Chemistry Instruction. Educación Química, 2013, 24(4), 431-438.
The generation and evaluation of scientific evidence and explanations is a fundamental scientific competency that science education should foster. As a learning strategy, self-explaining refers to students’ generation of inferences about causality, which in science can be related to making-sense of how and why phenomena happen. Substantial empirical research has shown that activities that elicit self-explaining enhance learning in the sciences. Despite the potential of self-explaining, college instruction often presents chemistry as a rhetoric of conclusions, thereby instilling the view that chemistry is a mere collection of facts. In addition to a frail understanding of the concept, other factors that may contribute to the underuse of self-explaining activities in college chemistry are the following: lack of an accessible corpus of literature and lack of research related to chemical education. This paper intends to contribute to improving the understanding of self-explaining in chemistry education and to describe the current state of research on self-explaining in tertiary level science education. This work stems from preliminary research to study ways to promote engagement in self-explaining during chemistry instruction and to assess how different levels of engagement influence learning of specific chemistry content.
Functionalization of Carbon Nanoparticles Modulates Inflammatory Cell Recruitment and NLRP3 Inflammasome Activation
5. Yang, M.; Flavin, K.; Kopf, I.; Radics, G.; Hearnden, C. H. A.; McManus, G. J.; Moran, B.; Villalta-Cerdas, A.; Echegoyen, L. A.; Giordani, S.; Lavelle, E. C. Functionalization of Carbon Nanoparticles Modulates Inflammatory Cell Recruitment and NLRP3 Inflammasome Activation. Small, 2013, 9(24), 4194-4206.
The inflammatory properties of carbon nanoparticles are regarded as a major roadblock in their use for biomedical applications. S. Giordani, E. C. Lavelle and co-workers describe a simple and reproducible strategy to address this issue using a novel purification process combined with surface chemical functionalization. The carbon nano-onions are also shown to promote less inflammation than carbon nanotubes and this can be further reduced by surface functionalization. This is the first report that single walled carbon nanotubes and carbon nano-onions have the ability to activate the NLRP3inflammasome.
Use of RateMyProfessors.com as a supplemental tool for the assessment of General Chemistry Instruction
4. Bergin, A., Sharp, K., Gatlin, T., Villalta-Cerdas, A., Gower, A., Sandi-Urena, S. Use of RateMyProfessors.com as a supplemental tool for the assessment of General Chemistry Instruction. Journal of Chemical Education, 2013, 90, 289-295.
Commercial online instructor evaluations have gained traction in influencing students’ decisions on professor and course selections at universities. RateMyProfessors.com (RMP) is the most popular of such evaluation tools and houses a wealth of information from the students’ viewpoint. The purpose of this study was to determine whether RMP data could be used to analyze and inform general chemistry instruction at a particular institution. The entire RMP database for the general chemistry program was sampled to produce a subset of 60 random RMP entries from six instructors. Each entry was composed of ratings in several areas and open-ended comments. The quantitative RMP data were consistent with measures from the institutional Student Evaluation of Instruction forms corresponding to the same instructors. In addition, a survey investigating RMP use patterns demonstrated that general chemistry students who contributed to RMP were not significantly different from the rest of the cohort across seven academic and demographic comparison criteria. The RMP qualitative information was analyzed using an inductive approach from which seven categories emerged as important to students’ learning environment. This analytical model allows for categorizing students’ statements in a systematic and meaningful manner to extract valuable supplemental information usable for program evaluation.
Electrochemical Properties of Oxidized Carbon Nano-Onions: DRIFTS-FTIR and Raman Spectroscopic Analyses
3. Plonska-Brzezinska, M.; Dubis, A.; Lapinski, A.; Villalta-Cerdas, A.; Echegoyen, L. Electrochemical Properties of Oxidized Carbon Nano-Onions: DRIFTS-FTIR and Raman Spectroscopic Analyses. A European Journal of Chemical Physics and Physical Chemistry, 2011, 12, 2659-2668.
The electrochemical reactions of carboxylic and lactone groups on carbon nano-onions (CNOs) in aqueous solutions result in non-Kolbe products: alcohols, ketones, ethers and epoxides. The anodic/cathodic conversion of ox-CNOs was assessed by Boehm titrations and by Raman and DRIFTS-FTIR (diffuse reflectance infrared Fourier transform spectroscopy). The electrochemical properties of oxidized carbon nano-onions were investigated by cyclic voltammetry in aqueous solutions. The ox-CNOs are electrochemically active as a result of the reduction of the oxygen-containing groups.
The synthesis and characterization of carbon nano-onions produced by solution ozonolysis
2. Plonska-Brzezinska, M.; Lapinski, A.; Wilczewska, A. Z.; Dubis, A.; Villalta-Cerdas, A.; Winkler, K.; Echegoyen, L. The synthesis and characterization of carbon nano-onions produced by solution ozonolysis. Carbon, 2011, 49, 5079-5089.
The room temperature oxidation of carbon nano-onions (CNOs) with ozone was investigated. The reaction was performed under mild conditions and oxidized products with high concentrations of oxygen-containing functional groups were obtained. The reaction products were characterized by Boehm titrations, additional oxidant/reductant treatments, and Raman and DRIFTS FT-IR spectroscopy. Electrochemical studies indicate changes in the surface chemistry of ozonized CNOs (oz-CNOs), exhibiting a larger total surface area and pore structure, which enables efficient accumulation of charge in the oz-CNOs film.
Electrochemical properties of composites containing small carbon nano-onions and solid polyelectrolytes
1. Breczko, J.; Winkler, K.; Plonska-Brzezinska, M.; Villalta-Cerdas, A.; Echegoyen, L. Electrochemical properties of composites containing small carbon nano-onions and solid polyelectrolytes. Journal of Materials Chemistry, 2010, 20, 7761-7768.
The preparation and electrochemical properties of a novel type of composite made of smallcarbon nano-onions (CNOs) with poly(diallyldimethylammonium chloride) (PDDA) or chitosan (Chit) were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Composite films on glassy carbon electrode surfaces were deposited by a coating method, applying a drop of solution containing the suspended CNOs and filler, PDDA or Chit. Composites form relatively porous structures on the electrode surface and exhibit typical capacitive behavior, as well as excellent mechanical and electrochemical stability over a wide potential window, from +600 to −600 mV. The capacitance of the films is primarily related to the amount of CNOs incorporated into the layer of the filler. The capacitance ranges between 20 and 30 F g−1 of incorporated CNOs. The composites also show a low relaxation time from resistive to capacitive behavior, therefore indicating that they can operate as capacitors in short time windows.