Joel W. Russell

Multimedia and Understanding: Expert and Novice Responses To Different Representations of Chemical Phenomena.

In two experiments, we examined how professional chemists (i.e., experts) and undergrad- uate chemistry students (i.e., novices) respond to a variety of chemistry representations (video segments, graphs, animations, and equations). In the first experiment, we provided subjects with a range of repre- sentations and asked them to group them together in any way that made sense to them. Both experts and novices created chemically meaningful groupings. Novices formed smaller groupings and more often used same-media representations. Experts used representations in multiple media to form larger groups. The rea- sons experts gave for their groupings were judged to be conceptual, while those of novices were judged to be based on surface features. In the second experiment, subjects were asked to transform a range of rep- resentations into specified alternative representations (e.g., given an equation and asked to draw a graph). Experts were better than novices in providing equivalent representations, particularly verbal descriptions for any given representation. We discuss the role that surface features of representations play in the un- derstanding of chemistry, and we emphasize the importance of developing representational competence in chemistry students. We draw implications for the role that multiple representations—particularly linguis- tic ones—should play in chemistry curriculum, instruction, and assessment.

The Roles of Representations and Tools in the Chemistry Laboratory and Their Implications for Chemistry Learning.

In this historical and observational study, we describe how scientists use representations and tools in the chemistry laboratory, and we derive implications from these findings for the design of educational environments. In our observations we found that chemists use representations and tools to mediate between the physical substances that they study and the aperceptual chemical entities and processes that underlie and account for the material qualities of these physical substances. There are 2 important, interrelated aspects of this mediational process: the material and the social. The 1st emphasizes the surface features of both physical phenomena and symbolic representations, features that can be perceived and manipulated. The 2nd underscores the inherently semiotic, rhetorical process whereby chemists claim that representations stand for unseen entities and processes. In elaborating on our analyses, we � Examine the historical origins and contemporary practices of representation use in one particular domain-chemistry-to look at how developments in the design of representations advance the development of a scientific community, as well as the understanding of scientists engaged in laboratory practice. � Examine representations spontaneously generated by chemists, as well as those generated by their tools or instruments, and look at how scientists-individually and collaboratively-coordinate these 2 types of representations with the material substances of their investigations to understand the structures and processes that underlie them. � Draw implications from the study of scientists to make recommendations for the design of learning environments and symbol systems that can support the use of representations by students to understand the structures and processes that underlie their scientific investigations and to engage them in the practices of knowledge-building communities.

The Cambridge Handbook of Multimedia Learning: Multimedia Learning of Chemistry

This chapter proposes the use of a “situative” theory to complement the cognitive theory of multimedia learning of chemistry. The chapter applies situative theory to examine the practices of chemists and to derive implications for the use of various kinds of representations in chemistry education. The two theories have implications for different but complementary educational goals—cognitive theory focusing on the learning of scientific concepts and situative theory on learning science as an investigative process. We go on to present and contrast several examples of multimedia in chemistry that address each goal. We critically review the current state of research on multimedia in chemistry and derive implications for theory development, instructional design and classroom practice, and future research in the area. This material is based upon work supported by the National Science Foundation under Grant No. 0125726. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Vibrational spectra of N-chloroaziridine and N-bromoaziridine

Abstract The infrared spectra of N-chloroaziridine, N-chloroaziridine- d 4 , and N-bromoaziridine were determined along with the Raman spectra of all but N-chloroaziridine- d 4 . A complete vibrational assignment has been made for N-chloroaziridine; all but one fundamental assigned for N-bromoaziridine, and a partial assignment proposed for N-chloroaziridine- d 4 . Correlation of the vibrational frequencies of the haloaziridines with aziridine strongly supports the Potts assignment for aziridine with one minor revision.

Infrared and Raman spectra of spiro[2.4]hepta-4,6-diene and [1,2-2H4]spiro[2.4]hepta-4,6-diene

Abstract The i.r. spectra of spiro[2.4]hepta-4,6-diene and of [1,2-2H4]spiro[2.4]hepta-4,6-diene have been measured for gas and liquid samples, for carbon disulfide and carbon tetrachloride solutions, and for samples matrix isolated in argon, krypton or nitrogen. The Raman spectra with depolarization ratios were determined for both isotopic molecules. Vibrational assignments for all fundamental modes of both molecules are proposed based upon polarizations of Raman lines, isotopic frequency shifts, and group frequencies in comparison with vibrational assignments of cyclopentadiene, cyclopropane and d6-cyclopropane.

Building Conceptual Frameworks with Synchronized Multiple Visualizations

Project to develop resources to meet the diverse needs of students entering first-year college chemistry, particularly through multimedia materials using multiple representations.