The purpose of this study was to investigate how research apprenticeships shaped students' views of the culture and practice of science. Twenty-seven 11th and 12th graders from across the United States and American Samoa participating in a summer research program were interviewed individually three times over 7 weeks. Seven students were selected as a representative focus group, and in addition to interviews, their journals, entrance questionnaires, and exit questionnaires were analyzed for what they revealed about students' ideas of what constituted scientific work, of the research process, of the existence and importance of communities in which they participated, and of the roles they played in these communities. Based on the pattern of student comments and perspectives, we identified four dimensions of scientific practice and culture whose salience and complexity increased and became articulated over the 7-week period. These dimensions included technical language, collaboration, uncertainty, and inquiry. The learning that took place with regard to these dimensions took place within three program-embedded communities, which we identified as laboratory-centered, program-centered, and peer-centered. The roles students played in these communities and the degree to which they could make use of resources within them contributed to students' view of scientific practice and culture, and to the development of the identity kits they began to construct of themselves as scientists. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 677-697, 1999 Objectives and Theoretical Framework One of the recent themes in educational research is the extent to which what students learn about science in school reflects how scientific ideas develop and are pursued in the real world. This emphasis is largely indebted to sociocultural research in which student understanding of scientific concepts, including the ability to create scientific arguments, is seen not as a product of the individual's isolated construction of knowledge and understanding, but through the lens JOURNAL

This paper tells the story of four sixth-grade students, of mixed race and social class, who worked together in a small group. All four students were intrigued as they experimented with colored solutions of different densities. They all wanted to share ideas about the techniques they had used, the observations they had made, and the patterns they had seen. They all wanted to understand why the colored solutions acted as they did. In spite of these common interests, they often failed to achieve intersubjective communication about the colored solutions or about the process of planning and making a poster to report their findings. We explain these failures using the sociolinguistic concepts of polysemy, privileging, and holding the floor. In particular, Carla (an African American girl) was unable to hold the floor within the group, so her opportunities for science learning were diminished. The four students were not overtly prejudiced in their speech or actions. Yet the expectations they brought with them about how and when people should talk, how work should be done, and what standards of quality they should aspire to led them to reconstruct among themselves some of the most troubling inequities of our society as a whole. This story is about important connections. In particular it is about how the actions of children are connected to the histories of their families, and how the privileging of ideas is connected to that of people, and how the practice of science is connected to that of discrimination. Science education reformers may underestimate the difficulty of separating conceptual conflict about ideas from interpersonal conflict about privilege and status.

The purpose of this work was to examine and characterize student use of narrative and paradigmatic expression in elementary science discourse. This interpretive study occurred over a 2-year period in a professional development school with a largely international population. This analysis focused on the narrative and paradigmatic modes of expression used by combined first-second-and second-grade students in a semistructured, fairly autonomous, whole-class conversational format. Students demonstrated competence with both modes of talk at the beginning of the year. Over time, students moved toward more paradigmatic talk, but narrative examples continued to be key components of the science conversations. Topically, students used narrative more often for life sciences and paradigmatic talk for physical sciences. For gender there were no qualitative differences in narrative or paradigmatic expression. However, boys obtained more opportunities to practice their use of both discourse forms by either receiving more speaking turns or expressing more language features per turn. These conversations show that narrative and paradigmatic modes in science need not be in opposition but can, in fact, be used together in complementary ways that are mutually enhancing. ß 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 2002 The purpose of this work was to examine and characterize student use of narrative and paradigmatic expression in elementary science discourse. This study occurred in a professional development school with a largely international population accommodating many students with beginning English skills. Our work there has focused on language through the integration of science and literacy with particular attention to oral discourse. Over the past several years we have

Previous studies have shown that a carcinogenic effect can be transmitted from female mice exposed prenatally to diethylstilbestrol (DES) to their female offspring. Furthermore, male mice exposed pre-natally to DES can transmit a carcinogenic effect to their offspring through their germ cells. To study how multi-generational carcinogenesis is transmitted through females exposed pre-natally to DES, the technique of blastocyst transfer was utilized. Blastocysts from strain CD-1 mice exposed pre-natally to vehicle were transferred to mice exposed pre-natally to DES. Among 143 offspring from these transfers, there were 10 ovarian adenomas and 10 uterine adenocarcinomas. Among 92 offspring from blastocyst transfers between mice exposed pre-natally to vehicle only, there was 1 ovarian adenoma and 1 uterine adenocarcinoma. Thus the pre-natal exposure of the host to DES produced a maternal environment which increased the incidence of ovarian and uterine tumors. The reverse type of transfer was also performed, in which blastocysts from female mice exposed pre-natally to DES were transferred into mice exposed to vehicle only pre-natally. Among 99 offspring derived from DES-exposed germ cells, 6 developed ovarian adenomas and 16 developed uterine adenocarcinomas. Thus DES also has a multi-generational effect transmitted through the blastocyst, which is consistent with fetal germ cell mutation from DES.

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