Fertility or sterility? Darwin,Naudin and the problem of experimental hybridity

Darwin came to realize that he could never devise an experiment that would demonstrate the development of new species by crossing hybrids. Instead, he turned to the problem of sterility within a species. The difference between Darwin's experimental and theoretical approach and that of French scientists working in the Muséum d'Histoire Naturelle in Paris can be shown most vividly by tracking Darwin's experiments in botany and his interest in those of Charles Naudin on hybrid plants. In his discussion of Mendel, Robert Olby has provided an interesting analysis of Naudin's hereditary concepts. I have approached some of the same work here with an emphasis on the question of sterility raised by Darwin, not simply between hybrids but within members of the same species and the light that he thought this could throw on both heredity and the origin of species.     

Effects of group size and advance organizers on learning parameters when using microcomputer tutorials in kinematics

The purpose of this study was to investigate how the use of CAI tutorial programs, incorporating advance organizers and involving various sizes of groups of subjects, would affect students' achievement scores, retention scores, and rates of learning. Used as subjects were 100 suburban high school physics students running interactive tutorial physics programs focusing on strobe simulation and displacement-time and velocity-time graphs. For fifty students (experimental group) an advance organizer program preceded each tutorial. The remaining fifty students (control group) had an advance non-organizer program preceding each tutorial. While pursuing the tutorials the students worked individually or together in groups of two, three, or four. Five days were allocated for the students to repeat the four tutorials until 90% competency level was attained. Achievement and retention were measured by individually administered paper-pencil teacher-made tests sampling the content of all four tutorials. Rate of learning was determined for groups by the number of times the first three tutorial programs were executed in order to attain 90% competency. In the two-way analysis of variance the only significant result at the 0.05 level pertained to group size. Results of the Tukey Test revealed that students working in groups of three and four on CAI tutorials had significantly better rates of learning than students working alone. No significant differences in achievement or retention were observed for the various groups. The implications for using CAI tutorials in physics point to grouping students in fours as a time saving and economic method of presenting material without significant loss of achievement or retention.     

Positioning Self in “figured worlds”: Using Poetic Inquiry to Theorize Transnational Experiences in Education

This study explores the process of using Holland et al. (Identity and agency in cultural worlds, Harvard University Press, Cambridge, 1998) “figured worlds” identity and agency theory to explore two scholars’ transnational experiences. Using poetic inquiry as a data analysis tool, this study seeks to (re)position how identity work is theorized and analyzed across broader contexts. Data collection consisted of online discussions, reflective journals, and biographical artifacts to better contextualize our discussions. These co-constructed discussions were transcribed and analyzed using poetic inquiry to better capture and articulate experiential themes of isolation, vulnerability, adaptation, and survival. This study serves three purposes (1) how both authors analyzed, interpreted and theorized our childhood experiences crossing borders using Holland et al. (Identity and agency in cultural worlds, Harvard University Press, Cambridge, 1998) “figured worlds” theory, (2) how poetic inquiry was used to capture the isolation, vulnerability, adaptation, and survival of one author’s experiences, and (3) how this type of reflexivity explicitly in/transforms theoretical approaches to deconstructing cultural identity and agency in a myriad of contexts, notably teacher education.     

A framework for designing interactive multimedia to scaffold young children's understanding of historical chronology

Young children's understanding of thehistorical past is often characterised by alack of temporal differentiation and a sense oftotal discontinuity with the present. Researchhas suggested that this situation may be causedin part by their formation of inappropriaterepresentations when solving problems ofchronology. To help children construct moreappropriate external representations forparticular tasks and reason more effectivelywith them about chronological concepts, weinvestigated the role that interactivemultimedia might play in scaffoldingteacher-led activities in the classroom. Inthis paper we report on our conceptual designand pedagogical approach to developingeffective dynamic, interactive representationsand activities at the computer interface, aimedat bridging the conceptual gap between concreteexperience and abstract concepts. Evaluationsof the software built using this frameworkshowed that the program was well received bychildren and teachers alike, and that it wasable to facilitate children's understanding of,and ability to reason about, chronology.     

“Touching the sentiments of everyone”;: Nationalism and state broadcasting in thirties Mexico

This paper provides a historical perspective on the intersection of media, popular culture, and nationalism through a study of the broadcasting policies and programs of one of Mexico's earliest government radio stations. This study analyzes the musical programs that formed the centerpiece of government radio programming in order to evaluate the racial and class ideologies imbedded in the nationalist discourse of state broadcasters. By viewing these government programs through the lens of a broader literature on nationalism in the Third World and among diasporic communities, it is possible to identify a fundamental tension in Mexico's official nationalism between a search for the roots of an “authentic”; ethnic identity, and a need to position Mexican culture within the constellation of Western “civilization.”; Finally, this paper investigates audience reactions to state broadcasts in order to explore the meaning of early broadcast nationalism for Mexico's radio listeners.