bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooperative Learning as a Sociocultural Practice
Authors: Liang Xiaoping
Published: June 2010

This study investigates Chinese immigrant high school students' perceptions of cooperative learning and their interactions during cooperative learning activities in English as a second language (ESL) classes. The findings present a complex picture of cooperative learning in the ESL classroom. The interview results demonstrate that the Chinese students had multiple and contradictory views of cooperative learning. They simultaneously liked and disliked working in groups. The observation data show that these students also produced multiple and conflicting discourses of cooperation, non-cooperation, and mis-cooperation as they worked on cooperative learning tasks. The themes of these contradictory discourses suggest that the Chinese students' everyday lived experiences of cooperative learning in ESL classes were shaped by dilemmatic qualities. The dilemmas these students encountered during cooperative learning tasks seem to derive from conflicting values and practices of the cultural, socio-economic, and educational worlds that these students experienced before and experience now.
Pedagogy, Purpose, and the Second Language Learner in On-Line Communities
Authors: Potts Diane
Published: June 2010

Information and communication technologies (ICTs) are often portrayed as offering a collaborative community space in which native and non-native language speakers reciprocally scaffold linguistic, cultural and content knowledge, a space which assists students in overcoming well-documented challenges encountered in traditional classrooms (Leki, 2001; Morita, 2000, 2004). However, recent studies point to the communicative disjunctures arising from variances in cultural capital and socio-technological histories in on-line dialogic encounters between student groups (see Belz, 2003; Kramsch & Thorne, 2002; Thorne, 2003, 2000). This article examines online community formation among participants in a graduate seminar on modern language education and the pedagogical design that facilitated the development of norms of joint construction of knowledge, reciprocity, and sharing. Drawing upon survey and interview data as well as on a descriptive statistical analysis of the bulletin board interaction, the study explores how design provided non-native speakers with opportunities to capitalize on their existing experiential and intellectual capital.
The Use of L1 in an L2 On-Line Chat Activity
Authors: Thoms Joshua , Liao Jianling , Szustak Anja
Published: June 2010

This study focuses on the use of the native language (L1) by second language (L2) learners when carrying out a collaborative jigsaw task in a computer chat environment. It investigates the extent and function of L1 use by means of a sociocultural theoretical framework. The research project was carried out in three languages: Chinese, German, and Spanish. Students were assigned to dyads at random and were asked to perform a jigsaw task activity. The chat logs were collected and analyzed via descriptive statistics and discourse analysis. The findings suggest that across all three languages, the students used their L1 (English) to varying degrees and for a variety of functions. ‘Moving the task along’ (Swain & Lapkin, 2000a) was the primary function of the L1. Further examination of the chat logs indicates that several factors affected the use of L1, such as participants' task management strategies and the use of symbols.
Grammaire de texte en contexte d'ALAO: une année avec le didacticielFreeText
Authors: Hamel Marie-Josée
Published: June 2010

Cet article présente FreeText, un didacticiel pour apprenants de français langue seconde (FLS) de niveau intermédiaire-avancé dont le concept didactique, élaboré par l'auteur à partir d'une approche en grammaire textuelle, propose une étude de la grammaire en contexte, par l'analyse de marques linguistiques qui caractérisent les textes. Y sont décrites les activités portant sur la compréhension et la production en langue seconde (L2) qui exploitent ce concept didactique dans FreeText, ainsi que les ressources et l'interface du didacticiel. La seconde partie de l'article fait le compte rendu d'une expérience pédagogique visant une première utilisation intensive de FreeText dans un contexte réel d'apprentissage, soit un cours universitaire de FLS. On y détaille le syllabus du cours, dont la démarche s'inscrit dans celle de FreeText et on y fait part des observations effectuées concernant la progression du groupe avec le didacticiel durant une année scolaire. La conclusion fait le point sur certaines compétences développées par les apprenants dans le contexte décrit et suggère quelques modifications qui faciliteraient l'utilisation de ce didacticiel.
Computer-Mediated Communication in Korean-English Chat Rooms: Tandem Learning in an International Languages Program
Authors: Chung Yang-Gyun , Graves Barbara , Wesche Mari , Barfurth Marion
Published: June 2010

This longitudinal case study draws on sociocultural theory to investigate language learning as a socially mediated process through computer-mediated communicative tasks in an international languages class. The study reports on the design, implementation, and outcomes of a thematic, task-based curricular innovation in which paired Korean- and English-speaking peers, each learning the other's language, collaborated on chat homework assignments. Examination of these chat interactions between experts and novices, with the tandem partners fulfilling each role in turn, reveals how on-line collaborative discourse supports knowledge building within this cross-linguistic learning environment. Data from chat exchanges show how these students were able to learn and teach contextually meaningful and appropriate linguistic and cultural behaviour through socially mediated actions, using the meaning-making resources within their own learning community. Specifically, the findings show the ways in which learners appropriated a variety of language practices, developed awareness of self in relation to others, and participated in expert and novice discursive practices in the construction of meaning.
Orientations to Learning German: Heritage Language Learning and Motivational Substrates
Authors: Noels Kimberly
Published: June 2010

This study examined how two motivational substrates may be differentially important depending upon the learner's language background. Students registered in German classes (N = 99) completed a questionnaire that assessed (a) their intrinsic, extrinsic, integrative, and instrumental reasons for learning German; (b) their feelings of autonomy, competence, and relatedness; and (c) their engagement in language learning and intergroup contact variables. The results show that heritage language learners were more likely than non-heritage learners to learn German because it was an important aspect of their self-concept. Moreover, although intrinsic and self-determined extrinsic orientations fostered motivation both for heritage and non-heritage learners, aspects of contact with the German community also played a role in motivated learning, particularly for heritage language learners.
Some Functions of Triadic Dialogue in the Classroom: Examples from L2 Research
Authors: Haneda Mari
Published: June 2010

This article argues that triadic dialogue (Lemke, 1990), much criticized in the past, has an important role to play in L2 learning and that its effectiveness should be judged in accordance with the particular pedagogical goals that it is made to serve. Drawing on three recent studies of L2 classrooms in a variety of instructional settings, the article provides illustrative examples of the effective use of different manifestations of triadic dialogue. The teachers in the three studies appear to use triadic dialogue for one or more of the following purposes: (a) a consecutive focus on content and language; (b) a simultaneous focus on content and language; (c) making interaction more dialogic; and (d) encouraging students to exercise their agency as participants. In all contexts, it appears to be critical that teachers attend to both intellectual and affective dimensions of learning in order to create a productive classroom community.
Teaching Talk as a Game of Catch
Authors: Kwon Minsook , Kellogg David
Published: June 2010

This article looks at two different primary EFL classrooms: one in which the teacher is a general-subject teacher who teaches different subjects to the same children and another in which the teacher is an EFL specialist who teaches the same subject to different groups of children. First we qualitatively characterize the differences in discourse, checking quantitatively to see if they hold true for the whole lesson. Second, we report on a three-year comparative study in which the same teacher taught the same material to both familiar and unfamiliar classes. Third, we suggest that the construction of the zone of proximal development (Vygotsky, 1978, p. 86) requires a rather different strategy in primary-school teaching than with secondary learners. Good primary discourse, we argue, may be less like a professional baseball pitcher's throw and more like a lazy game of Catch.
Variation in Advanced French Interlanguage: A Comparison of Three (Socio)linguistic Variables
Authors: Howard Martin
Published: June 2010

This article first presents an overview of some trends behind the acquisition of sociolinguistic variation in a second language. A study is then presented that aims to test the validity of these trends in a quantitative study of a range of socio- and morpho-phonetic variables in French, including liaison, /1/ deletion, and subject-verb agreement on irregular verbs in third-person-plural contexts. While such a comparative approach has been adopted in the case of Canadian immersion and naturalistic learners, the study presented here is concerned with Irish-instructed learners of French in the foreign language classroom. The study complements such previous work by further showing that the characteristics of the variables affect their differential acquisition by the instructed learner. The variables are discussed in relation to potential reasons for the similarities and differences in their acquisition.
Gender Differences in Motivation to Learn French
Authors: Kissau Scott
Published: June 2010

There is concern among second language educators in Canada that male students are losing interest in studying French as a second language (FSL). In response, in the fall of 2003, a study was conducted to investigate gender differences in second language (L2) motivation among Grade 9 core French students. Building upon the traditional model of L2 motivation that emphasizes learner attitudes toward the target-language community, the researcher broadened the concept of L2 motivation to include both societal and classroom-related factors. A mixed methodology was then employed to determine if gender differences in these factors exist among Grade 9 FSL students. Approximately 500 students in Grade 9 completed a questionnaire. The significant findings of the questionnaires were then explored in interviews with students and teachers. As the study progressed, it became apparent that societal perceptions of what is appropriate for males lay at the root of the identified.
Motivation, Ethnic Identity, and Post-Secondary Education Language Choices of Graduates of Intensive French Language Programs
Authors: Goldberg Erin , Noels Kimberly
Published: June 2010

This study investigates the motivation for learning French, the ethnic identities, and the decision to pursue post-secondary education in French of anglophone graduates of intensive French language programs in high school. Sixty-two graduates of either French immersion, Advanced Placement French, or the International Baccalaureate French program enrolled at an English-language post-secondary institution and 29 graduates of the same programs enrolled at a French-language facility completed a questionnaire including the Situated Ethnic Identity Scale (Noels, Saumure, Pino, Clément, & MacIntyre, 2006), the Language Learning Orientation Scale (Noels, Pelletier, Clément, & Vallerand, 2000), and a language use index. Results provided some evidence that students in the francophone institution were motivated to learn French for more self-determined reasons and that they also felt more strongly francophone and less strongly anglophone in some situations.
L'alternance codique chez les professeurs de français langue étrangère pendant des leçons orientées vers le développement des connaissances grammaticales
Authors: Gearon Margaret
Published: June 2010

Cet article est fondé sur une étude de l'utilisation de l'alternance codique chez trois professeurs de français langue étrangère dans des écoles secondaires en Australie. II nous semble que l'alternance codique devient une stratégie pédagogique surtout dans les leçons où les professeurs traitent un point grammatical. Nous avons choisi de nous concentrer sur l'enseignement du passé composé par ces trois professeurs, car ce temps verbal présente des problèmes pour les apprenants australiens. L'étude montre que l'alternance codique intersententielle pourrait aider les apprenants, mais que l'alternance intrasententielle leur donnerait l'idée que ce temps verbal fonctionne de la même façon dans les deux langues. Chez ces trois professeurs, l'alternance codique fonctionne comme un troisième code dans la salle de classe, l'équivalent de l'anglais et du français.
Testing the Development of French Word Knowledge by Advanced Dutch- and English-Speaking Learners and Native Speakers
Authors: Greidanus Tine , Beks Bianca , Wakely Richard
Published: June 2010

The present study is a continuation of the work presented in the 2001 article by Greidanus and Nienhuis. In the current study, we also examine the quality of word knowledge among advanced learners of French as a second language (L2) by means of a word associates test. We studied the development of word knowledge among six groups of university-level participants, who were (a) native speakers of French and (b) learners of French as a foreign language with two different first languages (L1s), Dutch and English. The format of the test differed from that used in the 2001 Greidanus and Nienhuis study as follows: (a) the tested words were less frequently used French words; (b) the participants were native speakers of French in addition to two categories of advanced learners of French; (c) the number of associate words (fixed or not) was an independent variable. The findings showed that both native and non-native speakers of French progressed in deep-word knowledge when the results of third- and fourth-year students were compared with those of first-year students. Although the test contained a considerable number of French-English cognates, the L1 English learners did not perform better than the Dutch learners. The words tested were not noticeably more difficult when chosen from the 10,000-word level rather than from the 5,000-word level.
L'utilisation de stratègies d'apprentissage en fonction de la réussite chez des adolescents apprenant l'anglais langue seconde
Authors: Lafontaine Marc
Published: June 2010

Cette étude visait à déterminer lesquelles des stratégies contenues dans la taxonomie de O'Malley et Chamot (1990), permettent de distinguer les bons des moins bons apprenants de langue seconde (L2). Un questionnaire comptant 80 stratégies a été élaboré et soumis à 310 francophones en 5° année d'études de niveau secondaire apprenant l'anglais. Les résultats de fin de semestre qui s'est tenu trois mois après le recueil des donnés ont été colligés. La note de l'épreuve de production, considérée plus discriminante, a servi à subdiviser l'échantillon en trois groupes: faible, moyen et fort. Les stratégies ont été examinées à partir d'une analyse de Kruskall-Wallis. Les résultats obtenus indiquent qu'un nombre limité des stratégies métacognitives, cognitives et socioaffectives à l'étude sont utilisées de façon statistiquement différente selon le niveau de compétence des apprenants. Ces résultats sont examinés dans l'optique de poursuivre la validation d'un instrument de mesure des stratégies pour les francophones apprenant l'anglais L2.
The Teacher is the Key: Building Trust in ESL High School Programs
Authors: Roessingh Hetty
Published: June 2010

Using a case-study approach, this inquiry examines the perceptions of 10 immigrant students regarding the ESL program provided at the high school they attended for three years. Their achievement outcomes and the ESL program design at this school have been the topics of previous publications; hence the quest for explanatory insights from the students' perspective. The orienting questions of this study relate to the students' understanding of the development of English language proficiency and their perceptions of the programmatic supports that made this possible. Findings suggest that trust is the overriding theme that determines whether or not students (and their parents) will support the program, but this is closely linked to academic outcomes/educational success. The specifics of the instructional paradigm on which the program is predicated are less of a concern. The teacher is the key in providing for the needs of these students and engendering the sense of trust that is essential if ESL learners are to benefit from ESL programs.
Employonsle françaisen français de base!
Authors: Turnbull Miles
Published: June 2010

Dans cet article, nous proposons des stratégies pratiques aux enseignant(e)s du francais de base de tous les niveaux scolaires, surtout aux nouveaux enseignant(e)s et à ceux ou celles inscrits aux programmes de formation initiale, pour les aider à maximiser l'emploi du francais dans leurs salles de classe. De plus, nous offrons quelques stratégies pour un emploi judicieux et sélectif de la LI au profit de l'apprentissage de la L2.
Uses and Functions of Formulaic Sequences in Second Language Speech: An Exploration of the Foundations of Fluency
Authors: Wood David
Published: June 2010

Abstract:

Formulaic sequences are fixed combinations of words that have a range of functions and uses in speech production and communication, and seem to be cognitively stored and retrieved by speakers as if they were single words. They can facilitate fluency in speech by making pauses shorter and less frequent, and allowing longer runs of speech between pauses. The present study was undertaken to identify the uses and functions of formulaic sequences in the development of speech fluency in narrative retelling in English as a second language (ESL). Spontaneous spoken narrative retells by ESL learners were analyzed for ways in which use of formulaic sequences may have facilitated fluency growth over a six-month period, be they pragmatic, functional, or strategic. Five categories of formula use emerged: repetition of a formula; use of multiple formulas to extend a run; reliance on one formula; use of self-talk and filler formulas; and use of formulas as rhetorical devices. These categories are illustrated by excerpts from transcripts of learner speech.
Comparing Focus on Form and Focus on FormS in Second-Language Vocabulary Learning
Authors: Laufer Batia
Published: June 2010

Abstract:

The study compares the effectiveness of Focus on Form (FonF) and Focus on FormS (FonFs) approaches in learning new L2 words by 158 high-school learners of English as L2. In phase 1 of the study, the FonF group read a text containing the target words, discussed it in small groups, and answered comprehension questions. The FonFs group studied the target words as discrete items with their meanings and examples of usage. In phase 2 of the study, all learners received the target words with their meanings and studied them for 15 minutes for a quiz. They were tested immediately after each phase, and two weeks later.

Results revealed significantly higher scores for FonFs group after phase 1, but the difference disappeared after phase 2. As learners cannot be expected to study all vocabulary for tests, form-focused instruction - and particularly FonFs - is claimed to be indispensable for L2 vocabulary learning.
How Large a Vocabulary is Needed For Reading and Listening?
Authors: Nation I.
Published: June 2010

This article has two goals: to report on the trialling of fourteen 1,000 word-family lists made from the British National Corpus, and to use these lists to see what vocabulary size is needed for unassisted comprehension of written and spoken English. The trialling showed that the lists were properly sequenced and there were no glaring omissions from the lists. If 98% coverage of a text is needed for unassisted comprehension, then a 8,000 to 9,000 word-family vocabulary is needed for comprehension of written text and a vocabulary of 6,000 to 7,000 for spoken text.
‘Like Pulling Teeth’: Oral Discourse Practices in a Culturally Diverse Language Arts Classroom
Authors: Wiltse Lynne
Published: June 2010

Abstract:

This article examines community practices, in particular oral discourse practices, in a junior high school classroom in an urban area of Western Canada. The purpose of the research was to determine what contribution a ‘community of practice’ (COP) framework could make to the study of social interaction in a classroom setting. Qualitative research methods were used to explore student-student and student-teacher interaction in a culturally and linguistically diverse Grade 9 classroom. Of particular interest was why a language arts teacher who claimed to love teaching through dialogue rarely initiated classroom discussion. Study findings demonstrated that the teacher's practices were shaped by the social structure of the classroom community. The article explores the teacher's role in disrupting cultural practices that limit students' participation. In conclusion, the article makes an argument for scaffolding to be added to the COP framework if it is to be utilized to advantage in classroom settings and suggests incorporating hybrid literacy practices in multilingual contexts.
Apprentissage coopératif et prises de parole en langue cible dans deux classes d'immersion
Authors: Mattar Cathérine , Blondin Christiane
Published: June 2010

Abstract:

Providing students with enough opportunities to speak and communicate in the target language is one of the challenges faced by both linguistic immersion and conventional language courses. The study documented here shows that cooperative learning, the efficiency of which has been demonstrated in various contexts, could help educators meet this challenge. Cooperative learning activities suggested by one of the researchers were organized by the teachers of two Grade 2 classes (7- and 8-year-old students) in partial immersion (German in one case, Dutch in the other). The speech acts among two heterogeneous groups of four children per class were recorded and analysed. The article shows that every pupil spoke not only in their L1 but also in the target language and that speech acts were fairly equally distributed within each group.
Elementary School EFL Learners' Vocabulary Learning: The Effects of Post-Reading Activities
Authors: Atay Derin , Kurt Gökce
Published: June 2010

Abstract:

As language learning involves the acquisition of thousands of words, teachers and learners alike would like to know how vocabulary learning can be fostered, especially in EFL settings where learners frequently acquire impoverished lexicons, despite years of formal study. Research indicates that reading is important but not sufficient for second-language vocabulary learning, and that it should be supplemented by post-reading activities to enhance students' vocabulary knowledge. The present study investigates the effects of two types of post-reading activities: discrete written tasks on their own and a combination of written tasks along with interactive tasks on the vocabulary acquisition of young learners in an EFL setting. A total of 62 Grade 6 students in two classes in a public school in Turkey participated in the study. Data were collected by the Cambridge English Test (CYLET) and Vocabulary Knowledge Scale (VKS). Results showed that the experimental group students outperformed the control group students in acquisition of both selected and unselected vocabulary items. The use of interactive tasks as post-reading activities proved to be an effective way of enhancing the L2 vocabulary knowledge of young learners.
Manley's “Feigned Scene”: The Fictions of Law at Westminster Hall
Authors: Temple Kathryn
Published: June 2010

The publication of Delarivier Manley's The New Atalantis resulted in her arrest for libel against the government; in The Adventures of Rivella, she recounted that arrest. While most critics focus on Manley's critique of government overall, attention to the intersection between her works and the law reveals that she was fascinated by and attracted to law and that her works critiqued law in both direct and indirect ways. Reading both her works and the development of seditious libel law as creative acts suggests the similarity between fictional works and the supposedly authentic and authoritative workings of law. Manley's representation of her appearance at Westminster Hall as essentially performative points towards the obsession observed within the law with theatricalization and performance. Manley's fictionalized representations of her relationship with the law, when read in light of law's fictions and what Manley saw as its deceptions, reveal law's own inner emotional life, its fictions, and in the end, its desire for fiction.
Tragedy and the Economics of Providence in Richardson's Clarissa
Authors: Hernandez Alex Eric
Published: June 2010

The postscript to the 1751 edition of Clarissa provides Samuel Richardson's most definitive explication of what he was doing through the novel's unfashionably tragic turn. This essay considers his project in light of the period's taste for narratives that culminate in poetic justice, arguing that the postscript identifies such notions of moral compensation as symptomatic of an age of scepticism. Richardson is thus engaged in reimagining older modes of providence at odds with middle-class values of exchange and an ascendant providential economy, fashioning a distinctive mode of tragedy that drew on both classical and biblical sources in which the very form of his novel interrogates bourgeois cultural norms. In this way, he queries the relations between eighteenth-century theology, early capitalist political economies, and moral action being negotiated through the novel's formation.
Histories of Female Progress in Memoirs of Modern Philosophers
Authors: Murray Julie
Published: June 2010

Elizabeth Hamilton's novel Memoirs of Modern Philosophers deploys the rubric of philosophical or conjectural history in order to argue for a model of female domesticity and to score many of her satirical points. Hamilton's satire subverts radical pretensions to progress by linking sexual opportunism with social opportunism: first, by identifying it with Hottentot savagery via Bridgetina and her Jacobin friends, and their plans to emigrate to Africa, and second, by identifying it with a barbarous era exemplified by Julia's seduction and ruin. By aligning Jacobinism and the New Philosophy with savagery and barbarism, Hamilton opens the way for Harriet, the only one of the three female characters who rejects the New Philosophy, to be aligned with the most advanced state of civilization, a modernity that sees the rise of female and domestic virtue. Hamilton's Whiggish history of female progress thus presents a challenge to certain understandings of conservative culture in the 1790s that implicitly align anti-Jacobin writers such as Hamilton with nostalgic defences of tradition.
Tsonnonthouan, Colonialism, and the Commodification of Culture
Authors: Richardson Robbie
Published: June 2010

During and following the Seven Years War, North American Indigenous people began to occupy a unique position in the British imaginary as compelling yet contradictory subjects, existing outside the culture of consumerism that was rapidly rising in Britain. The satirical novel Memoirs of the Life and Adventures of Tsonnonthouan (1763) mimicked both the ethnographic works that British people read in increasing numbers and the body of Grub Street texts imitating Tristram Shandy. The novel, which depicts “Indians” as consumers and worshippers of European commodities, negotiates the entanglement of culture and consumerism in both Britain and the colonies.
Halted by the Archive: The Impact of Excessive Archival Restrictions on Scholars
Authors: Panofsky Ruth , Moir Michael
Published: June 2010

This article, written from the dual perspectives of a scholar and an archivist, considers the impact of excessive archival restrictions on scholars who seek access to primary material in order to ensure the integrity and accuracy of their research. Ruth Panofsky's view is that of a literary scholar whose work is informed by archival research. Michael Moir's view is that of a university archivist who has facilitated scholarly access to York University's archival holdings. Together, they argue for access to fonds held in public archives and the need for archival institutions to provide and lobby for such access. In this article, author Panofsky draws on her recent work with the Adele Wiseman fonds, held in the Clara Thomas Archives, Scott Library, York University. Since that research was undertaken with great difficulty, the narrative that follows may dishearten some scholars. The eventual overcoming of the barrier of restricted access to archival material, which, for a number of years, hindered the progress of the Wiseman project, was due largely to dogged determination — her own, and that of the archival staff of York University. As this article shows, when scholars and archivists alike recognize ‘the archival home’ as a site ‘of constant discovery and excitement,’ 2 the viable outcome is research that is both vivid and sound.
Effect of temperature and strain rate on strain hardening and deformation mechanisms of high manganese austenitic steels
Authors: Bäumer Annette , Jiménez José Antonio , Bleck Wolfgang
Published: June 2010

The effect of temperature and strain rate on the mechanical properties of three Fe – Mn austenitic steels with Mn contents of 20 mass.% or above has been studied by tensile tests performed at strain rates ranging from 3 × 10−3 to 200s−1 and at temperatures between −160 and +140 °C. In these steels mechanical properties and strain hardening behaviour result from the competition between different deformation mechanisms including homogeneous or inhomogeneous dislocation glide, strain induced twinning or martensite formation. Thus, the microstructure evolution during deformation was investigated. For two of the steels, a relation of the deformation mechanisms (twinning and dislocation glide) at room temperature with the grain size was found. On the other hand, for the third steel at temperatures lower than 60 °C martensite is progressively formed during deformation. For the three steels, a decreasing volume fraction of twins or martensite with increasing testing temperature was found leading consequently to a decrease in flow stress and strain hardening.
Estimation of Freeway Work Zone Capacity through Simulation and Field Data
Authors: Heaslip Kevin , Kondyli Alexandra , Arguea Diego , Elefteriadou Lily , Sullivan Frank
Published: June 2010

The objective of this research was to develop analytical models and procedures for estimating the capacity of a freeway work zone by considering various geometric-, traffic-, and work zone–related parameters. The study was conducted in two stages: simulation-based modeling and field data collection. In the first stage, CORSIM (Version 5.1) was used to develop a comprehensive database for various work zone scenarios. Analytical models were developed to predict work zone capacity on the basis of these simulated data and previous literature findings considering three work zone configurations: two-to-one, three-to-two, and three-to-one lane closures. In the second stage, field data were collected at a freeway work zone to evaluate and refine the analytical models developed. Data were collected at the freeway work zone site during 15 evening peak periods, which included left- and right-lane closures as well as rainy weather conditions. The observed capacities were compared with those predicted by the new analytical models as well as to those estimated by the Highway Capacity Manual 2000. It was concluded that the analytical models developed predicted within 1% the capacity of the study work zone.
Level of Service Analysis of Freeway Weaving Segments
Authors: Roess Roger P. , Ulerio Jose M.
Published: June 2010

This paper reports on the product of NCHRP Project 3-75, which resulted in the development and calibration of new models for freeway weaving segments, including a draft chapter for the forthcoming Highway Capacity Manual (HCM). The most critical element of the current procedures in the HCM 2000 is the prediction of the average speeds of weaving and nonweaving vehicles in the weaving segment. These speeds are converted to an overall density for the segment that determines the prevailing or expected level of service. The proposed method does away with the strict assignment of weaving geometries to one of three configuration categories and also the need to determine whether the operation of the weaving segment is constrained or unconstrained. That approach led to the need to calibrate 12 equations to predict speeds. In research, this greatly increased the size of the desirable database for calibration. The new approach relies on the prediction of lane-changing activity within the weaving segment to quantify the impact of configuration and type of operation on resulting speeds and densities.
Validating the Incremental Queue Accumulation Method for Left-Turn Delay Estimation
Authors: Kyte Michael , Abdel-Rahim Ahmed , Dixon Michael , Li Jan-Mou , Strong Dennis
Published: June 2010

This paper examines the proposed incremental queue accumulation (IQA) method for the analysis of traffic flow at signalized intersections. The paper considers the formulation of the IQA method for protected plus permitted left turns. Validation of the model is presented by using the NGSIM high-resolution vehicle trajectory data set developed for an arterial in Atlanta, Georgia. A comparison of the existing Highway Capacity Manual (HCM 2000) method with the IQA method shows that the IQA approach produces delay estimates that are closer to field measurements. Several issues associated with the arrival and departure curves produced by the IQA method are examined.
Capacity of U-Turns at Unsignalized Median Openings on Six-Lane Streets
Authors: Liu Pan , Lu Jian John , Cao Bing
Published: June 2010

The primary objective of this study is to estimate the potential capacity of U-turns at unsignalized median openings on six-lane streets. To achieve the research objective, data were collected at seven unsignalized median openings in the Tampa Bay area of Florida. By using the maximum likelihood method and the Siegloch method, the research team estimated the critical headway and follow-up times for U-turns on six-lane streets. The critical headway was found to be 5.6 s. The follow-up time was found to be 2.3 s. With the estimated critical headway and follow-up time obtained, Harders's model was used for estimating the potential capacity of U-turns. The research team also estimated the conflicting traffic volume for U-turns. Model validation results show that the Harders model, which uses a weighted conflicting traffic volume, provides the best capacity estimates. The weighted conflicting traffic volume for U-turns on six-lane streets equals 2.2 times the average opposing major street traffic volume in each lane. Using the weighted conflicting traffic volume, Harders's model yields a mean absolute percent error (MAPE) of 17.8%. Even though the MAPE is relatively high, Harders's model does not systematically overestimate or underestimate the capacity of U-turns on six-lane streets. The results suggest that, with the parameters estimated in this study, the current capacity estimation methods provided by the Highway Capacity Manual can be applied to estimating U-turn capacity at unsignalized median openings on six-lane streets.
Investigation of Peak Flow Variations
Authors: Yi Ping , Wolfenbarger Jeanne , Raavi Venkata Suresh , Yu Lei
Published: June 2010

This paper studies peak flow factor (PFF) characteristics through analysis of the peak interval flow rate, the peak hourly volume, and the stability of their dynamic relationship. Despite wide recognition of the importance of the peak hour factor (PHF) in traffic studies, including capacity and level of service evaluation as well as measures of effectiveness analysis of highways and intersections, limited research has focused on PHF characteristics that are affected by variations of traffic conditions during the peak hour. The statistical properties of the PFF are analyzed and its changing patterns are compared at peak time intervals varying from 3 to 20 min. Field data from freeways, signalized intersections, and unsignalized intersections were used in the analysis. Results showed that the PFF became larger with an increase in the peak time interval and remained relatively stable for time intervals of 5 min or more for freeways and 10 min or more for intersections. Reliability tests indicated that the results of the PFF analysis based on field data were highly dependable.
Turbo Roundabouts
Authors: Fortuijn Lambertus G. H.
Published: June 2010

The Dutch turbo roundabout is characterized by predictable lane use and radial connecting entries. To calculate the capacity, in 1997 the multilane roundabout explorer was developed by modification of the capacity model of Bovy, which considered both separated lanes and pseudoconflict. Because of its linear structure, this model did not take into account multilane roundabout properties in a good way. Therefore a new model was developed by modification of the model of Hagring. Using only the gap acceptance approach to calibrate the parameters is not sufficient because the pseudoconflict is not taken into account. A combination with a stream approach is necessary. For validation of an analytic model, it is important to realize that the distribution of gaps offered in two flows simultaneously is determined primarily by a stochastic process. Thus, it is possible to test the effect of the distribution of the flows over two circulatory lanes by using a microsimulation model. The parameters needed to tailor VISSIM microsimulation software for this purpose were estimated. It is concluded that a VISSIM model may be suitable for the analysis of both single-lane and two-lane roundabouts. This paper deals with this combined approach. The findings are that ( a) the pseudoconflict should be taken into account and ( b) the turbo roundabout will have a larger capacity than the Dutch standard concentric double-lane roundabout because of the better circulatory lane-split.
Effect of Phase Countdown Timers on Queue Discharge Characteristics under Heterogeneous Traffic Conditions
Authors: Sharma Anuj , Vanajakshi Lelitha , Rao Nageswara
Published: June 2010

Analysis of queue discharge characteristics at signalized intersections is a primary component of traffic signal analysis and design. On the basis of previous studies, mainly conducted in homogeneous traffic conditions, the discharge headway is assumed to be high at the start of green for the first few vehicles, mainly because of start-up lost times, and is also assumed to reach the minimum value by the fourth or fifth vehicle in the queue. The minimum headway is expected to continue until the end of the queue. However, this may not be the case under heterogeneous traffic conditions, such as those in India, which has the additional problem of lacking lane discipline. Most of the signals in India include a countdown timer that indicates the time left for the signal phase, which is also expected to affect queue discharge characteristics. This paper presents insights gained on queue discharge characteristics at signalized intersections under heterogeneous traffic conditions and on the effect of a countdown timer on the headway distribution. The analysis was carried out using data collected from two intersections, one with a timer and one without, in Chennai, India, through the use of a videographic technique. The data collected are classified into three discharge regimes: start-queue, mid-queue, and end-queue. Linear regression models are used to assess the impact of vehicle types on queue discharge characteristics. The results indicate that the accepted headway distribution is followed when there is no timer. However, with the presence of a timer, there is a clear change in the trend for reduced start-up lost time and end lost time.
Performance Measures for Truck Level of Service
Authors: Ko Byungkon , Washburn Scott S. , McLeod Douglas S.
Published: June 2010

The current Highway Capacity Manual (HCM) provides analytical methods to evaluate performance levels of transportation facilities and to estimate level of service (LOS) perceived by the users. The HCM methodologies yield a single LOS value for all users in a traffic stream. However, because of the unique size and operating characteristics of large trucks, truck mode users may perceive LOS on various roadway facilities on the basis of different criteria than those of other mode users. A study was conducted to determine, from an LOS perspective, what roadway, traffic, and control issues should be focused on to better serve the needs of the trucking community. This paper describes the second part of the study, in which a survey of truck drivers and truck company managers was performed to quantitatively measure the relative importance, satisfaction, and improvement priority of truck LOS determinants and to examine which aspects of a truck trip should be analyzed to estimate truck LOS on each roadway type. Speed variance and pavement quality were identified as the service measures for truck LOS on freeways, while percent time being followed, percent time spent following, and travel lane and shoulder width and their pavement quality were identified for truck LOS on two-lane highways. Truck trip quality on urban arterials was found to depend on factors such as ease of turning maneuver, speed variance, traffic density, and pavement quality. Other drivers’ behavior, pavement condition, level of congestion, and frequency and timing of construction activities were common major contributors to truck LOS regardless of roadway type.
Capacities of Unsignalized Intersections under Mixed Vehicular and Nonmotorized Traffic Conditions
Authors: Li Haiyuan , Deng Wei , Tian Zong , Hu Peifeng
Published: June 2010

Unsignalized intersections consist of three types–-two-way stop-controlled, all-way stop-controlled, and uncontrolled intersections–- all with different priority relationships between traffic movements according to traffic laws. A conflict technique method was used to develop capacity models for the three types of unsignalized intersections under mixed traffic conditions involving vehicular, bicycle, and pedestrian movements. With field data collected from several unsignalized intersections, the model parameters were calibrated by a comparison analysis of traffic conditions in China and were modified on the basis of actual traffic conditions. The capacities obtained by the proposed models matched well with the observed capacities and the capacities calculated by conventional methods, both of which verified the effectiveness of the proposed models. The models proved to be valuable tools for determining capacities of vehicular movements at unsignalized intersections.
Replication of Work Zone Capacity Values in a Simulation Model
Authors: Chatterjee Indrajit , Edara Praveen , Menneni Sandeep , Sun Carlos
Published: June 2010

Evaluating the traffic impacts of work zones is vital for any transportation agency to plan and schedule work activity. Traffic impacts can be estimated by using microscopic simulation models. One challenge in using these software models is obtaining the desired work zone capacity values, which tend to vary from state to state. Thus, the default parameter values in the model that are suitable for normal traffic conditions are unsuitable for work zone conditions, let alone for conditions specific to particular states. Although a few studies have been conducted on parameter selection to obtain desired capacity values, none of them have provided a convenient look-up table (or chart) for the parameter values that will replicate field-observed capacities. Without such provision it has not been possible for state agencies to use any of the research recommendations. This study provides the practitioner a simple method for choosing appropriate values of driving behavior parameters in the VISSIM microsimulation model to match the desired field capacity for work zones operating in a typical early-merge system. The two most significant car-following parameters and one lane-changing parameter were selected and varied to obtain different work zone capacity values. CC1 is the desired time headway, CC2 is the longitudinal following threshold during a following process, and the safety distance reduction factor is representative of lane-changing aggressiveness. It has been verified that the recommended parameter values not only produce the desired capacities but also create traffic conditions consistent with traffic flow theory.
Long-term outcome of lumbar disc surgery: an experience from Pakistan
Authors: Bakhsh Ahmed
Published: June 2010

Object

The author conducted a study to determine the long-term outcome of lumbar disc surgery on relief of sciatic leg pain.

Methods

This was a retrospective observational study conducted at Fauji Foundation Hospital, Rawalpindi, Pakistan. The author reviewed medical records of 68 patients who underwent lumbar disc surgery for sciatic pain during the period 1995–2004. All patients were physically examined and interviewed.

Results

Lumbar disc surgery yielded complete pain relief in 79.41% of the cases. In 14.7% of the cases surgery failed to give any pain relief, and in 5.88% it yielded partial pain relief. At up to 10 years postoperatively, 27.77% of patients remained absolutely pain free. Pain recurred in 12.82% of cases after 1 year, in 35.89% during the first 5 years, and in 51.28% after 10 years. Pain recurred in the same leg in 63.88%, in the contralateral leg in 19.44%, and in both legs in 16.66%. Neurological deficits did not improve in any case except in 1 case of foot drop. New neurological deficits developed postoperatively in 8.82% of cases in the form of foot drop and calf muscle weakness.

Conclusions

Surgery provided immediate pain relief in 79.41% of cases, but the long-term outcome of lumbar disc surgery was not satisfactory.