bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of analogies used by science teachers
Authors: Dagher Zoubeida R. 
Published: October 2006

AbstractScience teachers use analogies that display a rich variety of form and content. An account of science teacher analogies that relies solely on systems of analysis imported from other fields of inquiry tends to obscure the unique features of these analogies as they operate within classroom discourse. This study examines teachers' analogies in context and highlights some of their special characteristics. The purpose of this analysis is to increase our understanding of how analogies operate in naturalistic instructional settings and to generate new research questions about science teaching and learning in view of the broader dimensions of the curriculum.Science isa very human activity. It involves human actors and judgements, rivalries and antagonisms, mysteries and surprises, the creative use of metaphor and analogy. It is fallible, often uncertain, and sometimes creatively ambiguous [Lemke, 1990, p. 134].
Biology teachers' perceptions of subject matter structure and its relationship to classroom practice
Authors: Gess‐Newsome Julie , Lederman Norman G. 
Published: October 2006

AbstractThe purpose of this investigation was to determine the nature of biology teachers' global content understandings (herein called subject matter structure‐SMS), the sources and formation of SMSs, and the variables that differentially affected teachers' abilities to translate SMSs into classroom practice. Case studies of 5 experienced biology teachers were constructed through interviews, classroom observations, and analysis of instructional materials. The data were qualitatively analyzed to describe the SMS exhibited by the teacher in the classroom and compared to SMSs provided by the teachers in postobservation interviews. The teachers' SMSs for biology were based on discrete content topics rather than conceptually integrated themes. Though most teachers recognized the integrated nature of biology, few used such conceptions to guide practice purposefully. The initial formation of SMSs were typically credited to college content courses and modified by the act of teaching. Opportunities for reflection and reinforcement seemed critical for the formation of coherent SMSs. The relationship of SMSs to classroom practice was complex and varied. The most direct form of translation occurred in the scope of course content. Variables that differentially affected SMS translation (typically through mitigation) included teacher intentions, content knowledge, pedagogical knowledge, students, teacher autonomy, and time.
Talking about science: An interpretation of the effects of teacher talk in a high school science classroom
Authors: Moje Elizabeth B. 
Published: October 2006

AbstractThis paper builds on research in science education, secondary education, and sociolinguistics by arguing that high school classrooms can be considered speech communities in which language may be selectively used and imposed on students as a means of fostering academic speech community identification. To demonstrate the ways in which a high school teacher's language use may encourage subject area identification, the results of an interactionist analysis of data from a 2‐year ethnographic study of one high school chemistry classroom are presented. Findings indicate that this teacher's uses of language fell into three related categories. These uses of language served to foster identification with the academic speech community of science. As a result of the teacher's talk about science according to these three patterns, students developed or reinforced particular views of science. In addition, talking about science in ways that fostered identity with the discipline promoted the teacher as expert and built classroom solidarity or community. These results are discussed in light of sociolinguistic research on classroom competence and of the assertions of science educators regarding social and ideologic implications of language use in science instruction.
Determining the conceptions of teaching science held by experienced high school science teachers
Authors: Hewson Peter W. , Kerby Holly Walter , Cook Perry A. 
Published: October 2006

AbstractThe article describes the process of analysis for determining a teacher's conception of teaching science using an available interview task. The analytical process provides a transparent link between teachers' spoken words and the different representations of their conceptions of teaching science. Representations of a teacher's conception of teaching science include a grid for analyzing different themes in a teacher's conception, a brief summary of the themes, and a longer written interpretive summary. Because these representations are based on the fundamental components of teaching science, they allow the uniqueness of both specific and structural aspects of teachers' views to emerge, and they facilitate comparisons between teachers. The analysis and its outcomes are exemplified using interviews with several experienced high school science teachers.
Investigation of worldview theory in a south african context
Authors: Lawrenz Frances , Gray Brian 
Published: October 2006

AbstractThis article reports on an exploratory investigation carried out to identify conceptions of some components of worldview, based on logicostructural worldview theory, held by science student teachers in a South African context. It explores relationships among worldviews, student characteristics, and scientific concepts. The sample included 48 final‐year science student teachers. Data were gathered by a questionnaire with follow‐up interviews. Questions were based on Kearney's model of worldview with stimulus items related to each of seven worldview categories. Responses were categorized and examined for possible relationships. Results of the investigation indicated that students' conceptions of time and distance were nonmechanistic and psychologically bound and that authoritarian scientific explanation was considered as sufficient for proof. Some significant relationships were found between items as well as between field of study and scientific conceptions.
Science knowledge and cognitive strategy use among culturally and linguistically diverse students
Authors: Lee Okhee , Fradd Sandra H. , Sutman Frank X. 
Published: October 2006

AbstractScience performance is determined, to a large extent, by what students already know about science (i.e., science knowledge) and what techniques or methods students use in performing science tasks (i.e., cognitive strategies). This study describes and compares science knowledge, science vocabulary, and cognitive strategy use among four diverse groups of elementary students: (a) monolingual English Caucasian, (b) African‐American, (c) bilingual Spanish, and (d) bilingual Haitian Creole. To facilitate science performance in culturally and linguistically congruent settings, the study included student dyads and teachers of the same language, culture, and gender. Science performance was observed using three science tasks: weather phenomena, simple machines, and buoyancy. Data analysis involved a range of qualitative methods focusing on major themes and patterns, and quantitative methods using coding systems to summarize frequencies and total scores. The findings reveal distinct patterns of science knowledge, science vocabulary, and cognitive strategy use among the four language and culture groups. The findings also indicate relationships among science knowledge, science vocabulary, and cognitive strategy use. These findings raise important issues about science instruction for culturally and linguistically diverse groups of students.
Students' and teachers' misapplication of le chatelier's principle: Implications for the teaching of chemical equilibrium
Authors: Quílez‐Pardo Juan , Solaz‐Portolés Joan Josep 
Published: October 2006

AbstractThe aim of this article was to study the reasons, strategies, and procedures that both students and teachers use to solve some chemical equilibrium questions and problems. Inappropriate conceptions on teaching and a lack of knowledge regarding the limited usefulness of Le Chatelier's principle, with its vague and ambiguous formulation and textbook presentation, may be some of the sources of misconceptions about the prediction of the effect of changing conditions on chemical equilibrium. To diagnose misconceptions and their possible sources, a written test was developed and administered to 170 1st‐year university chemistry students. A chemical equilibrium problem, relating to the students' test, was solved by 40 chemistry teachers. First, we ascertained that teacher's conceptions might influence the problem‐solving strategies of the learner. Based on this first aspect, our discussion also concerns students' and teachers' misconceptions related to the Le Chatelier's principle. Misconceptions emerged through: (a) misapplication and misunderstanding of Le Chatelier's principle; (b) use of rote‐learning recall and algorithmic procedures; (c) incorrect control of the variables involved; (d) limited use of the chemical equilibrium law; (e) a lack of mastery of chemical equilibrium principles and difficulty in transferring such principles to new situations. To avoid chemical equilibrium misconceptions, a specific pattern of conceptual and methodological change may be considered.
Effects of concept and vee mappings under three learning modes on students' cognitive achievement in ecology and genetics
Authors: Esiobu Gladys O. , Soyibo Kola 
Published: October 2006

AbstractThis study verified the efficacy of concept and vee mapping heuristics under cooperative (CP), cooperative–competitive (CP‐CM) and individualistic whole (IW) class learning conditions in improving students' achievement in ecology and genetics. A total of 808 tenth‐grade students were involved in the study. The results showed that the experimental groups taught with concept and vee mappings under the three learning modes achieved significantly better than the control groups. Students in the CP‐CM condition in all groups achieved significantly better than their counterparts in the other two groups, whereas the CP‐CM experimental group students achieved significantly best. A significant interaction between treatment and ability suggested that an element of competition, when combined with small group cooperation, favored students of lower ability.
Navigating a sea of ideas: Teacher and students negotiate a course toward mutual relevance
Authors: Flick Lawrence B. 
Published: October 2006

AbstractTheories of social cognition and verbal communication were used to analyze the science teaching of an experienced fourth‐grade teacher. Her teaching skills in language arts and reading were assets in negotiating the rapid flow of relatively unstructured information typical of inquiry in elementary classrooms, to help students generate relevant information about hands‐on experience. The teacher was a collaborator in this case study of her thinking and instructional planning, and her students' learning in a unit of instruction about space. Implications for elementary science instruction include recognizing the importance of embedded speech in conceptually broad discussions with students. Efforts to reform elementary science instruction should attend to these instructional skills more common to language arts instruction.
Problems in Teaching the Topic of Redox Reactions: Actions and Conceptions of Chemistry Teachers
Authors: De Jong Onno , Acampo Jeannine , Verdonk Adri 
Published: October 2006

AbstractAlthough there is growing interest in studies of teachers' actions and conceptions, little is known about content‐related teaching problems arising in science classrooms. This article presents a case study of problems which can occur when teaching the topic of redox reactions to Grade 11 students. Two chemistry teachers, a senior and a junior teacher, were involved in the study. Their reflective comments on the teaching problems were also investigated. Research data were obtained from classroom observations and audiotaped recordings of classroom practice. After the lessons, we conducted semistructured interviews with the teachers. The teaching problems are reported in terms of teaching activities causing difficulties for students in considering new conceptions to be necessary, intelligible, plausible, or fruitful. Analyses of the teachers' comments on these teaching activities clarifies a number of reasons why they acted as they did. It can be concluded that teachers' scientific expertise is an important source of difficulties when teaching redox reactions. Implications for an improvement of current chemistry classroom practice and content‐related teacher training are offered.
Confronting the Evolution Education Abyss
Authors: Zook Douglas 
Published: October 2006

AbstractThis article discusses recent evolution education literature and highlights key themes and perspectives recognized in the scientific community but only minimally exposed within either the science classroom or the science education research agenda. Examples include: macroevolution, expressed as the history of life on earth; the microbial dominance of most of earth time as a learning tool and theme organizer; sym‐biogenesis and frequently accompanying horizontal gene transfer; Lamarck and the roles of others traditionally ridiculed in evolution study; and new views of fundamental evolution topics such as speciation. Several recommendations are given to address these important omissions within the science educator community.
Regulation of reproduction rate in a cyclic population of the red‐backed vole, Clethrionomys rufocanus bedfordiae
Authors: Nakata Keisuke 
Published: October 2006

SummaryChanges of the components of reproduction were analyzed quantitatively in a two‐year cyclic population (which has two peaks in alternate years during a five‐year census) of the red‐backed vole, Clethrionomys rufocanus bedfordiae, with reference to its regulatory mechanism: (1) Variation in sex ratios was not associated with population phase or density, although a higher percentage of females in mature individuals was observed in the increase phase. (2) Females attained to sexual maturity at younger age and at lighter body weight than did males. All the youngest mature individuals were found in the low and the increase phases. Age and size at maturity became older and larger as the population went toward the peak phase. (3) Maturation rate was strongly associated with population phase and density; this component is an important and good parameter to predict population trend. Maturation rates were in the order, the low phase>the increase phase>the peak phase>the decline phase; the differences in the rates among these phases were significant. Maturation rate was somewhat depressed when the population density exceeded about 40 individuals/ha. Changes in age at maturity and in maturation rate are interpreted as derivative phenomena related to the population density and the capacity of the number of mature voles per unit area. (4) The maximum number of mature individuals were 26 males/ha and 29 females/ha; there was almost no increase of the number of mature voles at higher population densities over about 40 individuals/ha. The number of exclusive home ranges per hectare calculated from the observed range lengths did not differ much from the maximum number of mature voles of either sex. (5) Length of breeding period was shorter in the high‐density years than in the low‐density years; the breeding started earlier and ended earlier in the former than that in the latter. In the increase phase a few voles reproduced in winter. (6) The percentage of pregnant females was significantly lower in the peak phase than those in the other phases.
Genetic variance and covariance patterns of larval development in the small white butterfly Pieris rapae crucivora Boisduval
Authors: Tanaka Y. 
Published: October 2006

SummaryQuantitative genetic theory indicates that genetic covariance patterns among life history characters should have played an important role as genetic constraint in life history evolution. Highly positve (and negative) genetic correlations between larval development time (or larval growth rate) and adult size characters were detected by means of sib analysis for the small white butterfly Pieris rapae crucivora. The genetic associations suggested that evolution of developmental characteristics and adult phenotypic traits were constrained by pleiotropy. The positive genetic correlations between development time and adult body size may be compatible with the trade‐off between them, but the negative genetic correlations between larval growth rate and adult body size are not predicted from theories of optimal energy allocation. That phenotypic correlations drastically differed from the genetic correlations indicates limitations of evolutionary inferences based only on phenotypic variation.
The screw‐worm fly Chrysomya bezziana villeneuve (Diptera: Calliphoridae) in a sterile insect release trial in Papua New Guinea
Authors: Spradbery J. P. , Tozer R. S. , Robb J. M. , Cassells P. 
Published: October 2006

SummaryThe feasibility of the sterile insect release method (SIRM) was tested against natural populations of the Old World screw‐worm fly, Chrysomya bezziana in the Musa Valley, Papua New Guinea. Sterile mating frequencies were determined from egg masses laid by native females on wounded, sentinel cattle. The aerial release of sterilised puparia resulted in low frequencies of sterile matings and few trap recaptures of released material. The release of chilled adult flies resulted in higher frequencies of sterile matings and many trap recaptures. The mean density of males released was 230 males per km2 per week over a target area of 361 km2 (48% of the valley). Sterile masses were first detected 2 weeks after the release of chill flies commenced, reaching a weekly peak of 33% after 5 weeks of releases with 15% of egg masses found to be sterile during the final month. The levels of sterile matings achieved in this trial were similar to comparable SIRM studies made in the USA, Mexico and Guatemala to control the New World screw‐worm fly, Cochliomyia hominivorax.
Nectar secretion pattern of the dish‐shaped flower, Cayratia japonica (Vitaceae), and nectar utilization patterns by insect visitors
Authors: Kakutani Takehiko , Inoue Tamiji , Kato Makoto 
Published: October 2006

SummaryWe studied the relationship between the diurnal nectar secretion pattern of flowers of Cayratia japonica and insect visiting patterns to these flowers. Flower morphology of C. japonica changed greatly for about 12 hours after flower‐opening and the maximum duration of nectar secretion was 2 days. The nectar volume peaked at 11∶00 and 15∶00, and declined at night and at 13∶00 regardless of time elapsed after flower‐opening. The nectar volume at the two peaks was, on average, 0.25 μl on bagged inflorescences and 0.1μl on unbagged inflorescences (both, sugar concentration=60%). The flower secreted nectar compensatory when the nectar was removed. This means that insects consume more nectar than the difference of nectar volume between bagged and unbagged flowers.Apis cerana is a primary visitor of this flower, and was the only species for which we confirmed pollen on the body, among many species of flower visiting insects to this flower. Apis cerana visited intensively at the two peaks of nectar secretion. Visits of the other insects were rather constant or intensive only when there was no nectar secretion. Thus flowers of C. japonica with morphologically unprotected nectaries may increase likelihood that their nectar is used by certain pollinators, by controlling the nectar secretion time in day. In this study the pattern of nectar secretion allowed A. cerana maximum harvest of nectar.
Impact of lek mating on the sterile insect technique: A modeling study
Authors: Horng Shwu‐Bin , Plant Richard E. 
Published: October 2006

SummaryModelling studies are presented which describe the effect of lek mating on the control of a wild population by sterile male release. The mixed leks are assumed to follow a Poisson‐binomial distribution and the system includes three parts: territory defense, matings inside a lek and matings outside a lek. The effects of parameters on the hatchability are discussed. Among the parameters, sterile type effect (Ws), female choice (fs) and mating competitiveness (Cm) are the most important. The application to determining the effects of sterile male release and on the proportion of sterile males required for eradication are also discussed.
Differential diet breadths and species coexistence in leafroller‐hunting eumenid wasps
Authors: Itino Takao 
Published: October 2006

SummaryThere are, at least, three possible ways in which similar species coexist; resource partitioning, interference competition, and exploitation competition. Here, I investigated which way contributed to the coexistence of leafroller‐hunting eumenid wasp species. Resource partitioning and, in addition, differential diet breadths proved to promote species coexistence in this case.First, I analyze the prey records and diet overlap of four eumenid species in a local area. The larger two eumenids hunted similar‐sized prey items and had similar potential taxonomic prey uses. But the diet breadth of the subsocial eumenid was much wider than that of the solitary one. As a result, the diet overlap between the two large eumenids decreased. This was because the solitary eumenid attend repeatedly to the same hunting site inhabited by one abundant prey species, while the subsocial one made random hunting. On the other hand, the two medium‐sized eumenids partitioned resources according to prey size.Secondly, I related these results to prey choice by several other species of eumenid obtained from literature sources. Ten Japanese common eumenids were divided into four groups according to their prey size. In each of the four groups, 2 to 3 wasp species differentiated the habitat (1 group) or coexisted by means of differential diet breadths (parallel with differential sociality, 2 groups).
A model of the species rank‐abundance relation for a community in an open habitat
Authors: Kobayashi Shiro 
Published: October 2006

SummaryA mathematical model is proposed to describe the relationship between the abundance and the rank of species in order from the most abundant to the least in a community in an open habitat. This model is derived as a corollary of a species‐area equation (Kobayashi, 1975) which could be expected in the case where the individuals of each species are uniformly distributed over a habitat area. Numerical simulation reveals that a rank‐abundance curve for a universe results in different species‐area or species‐individual curves according to the spatial distribution of individuals, and that the relative abundance of each species in a sample varies with sample size unless the spatial distribution of individuals is uniform. A species‐individual curve obtained bySanders's (1968) rarefaction method agrees with that observed actually only for the spatially uniform distribution. Change in the pattern of rank‐abundance curve with species diversity and with sample size is discussed in relation to the present model.