语境在语篇理解中的作用

语境简单说就是言语所处的环境,它在语篇理解过程中起着重要作用.其作用主要有两种:解释作用和制约作用.语境的解释作用是指语境为某一语篇的理解提供解释.其主要表现有:(1)确定指示词的所指;(2)推导话语含义;(3)识别隐喻、反复、反语等修辞手段.语境的限制作用是指语境对某一语言单位在语篇中的意义的选择和确定所起的限制作用.其主要表现有:(1)推导语境意义;(2)排除歧义;(3)消除意义模糊现象.     

Deaf college students' comprehension of relational language in arithmetic compare problems

In this study of deaf college students' performance solving compare word problems, relational statements were either consistent or inconsistent with the arithmetic operation required for the solutions. The results support the consistency hypothesis Lewis and Mayer (1987) proposed based on research with hearing students. That is, deaf students were more likely to miscomprehend a relational statement and commit a reversal error when the required arithmetic operation was inconsistent with the statement's relational term (e.g., having to add when the relational term was less than). Also, the reversal error effect with inconsistent word problems was magnified when the relational statement was a marked term (e.g., a negative adjective such as less than) rather than an unmarked term (e.g., a positive adjective such as more than). Reading ability levels of deaf students influenced their performance in a number of ways. As predicted, there was a decrease in goal-monitoring errors, multiple errors, and the number of problems left blank as the reading levels of students increased. Contrary to expectations, higher reading skills did not affect the frequency of reversal errors.     

There’s more to the multimedia effect than meets the eye: is seeing pictures believing?

Textbooks in applied mathematics often use graphs to explain the meaning of formulae, even though their benefit is still not fully explored. To test processes underlying this assumed multimedia effect we collected performance scores, eye movements, and think-aloud protocols from students solving problems in vector calculus with and without graphs. Results showed no overall multimedia effect, but instead an effect to confirm statements that were accompanied by graphs, irrespective of whether these statements were true or false. Eye movement and verbal data shed light on this surprising finding. Students looked proportionally less at the text and the problem statement when a graph was present. Moreover, they experienced more mental effort with the graph, as indicated by more silent pauses in thinking aloud. Hence, students actively processed the graphs. This, however, was not sufficient. Further analysis revealed that the more students looked at the statement, the better they performed. Thus, in the multimedia condition the graph drew students’ attention and cognitive capacities away from focusing on the statement. A good alternative strategy in the multimedia condition was to frequently look between graph and problem statement, and thus to integrate their information. In conclusion, graphs influence where students look and what they process, and may even mislead them into believing accompanying information. Thus, teachers and textbook designers should be very critical on when to use graphs and carefully consider how the graphs are integrated with other parts of the problem.     

Problem length as a structural variable in verbal arithmetic problems

Of five structural variables that in previous studies accounted for a significant amount of the observed variance in the error rate in verbal arthmetic problems, the length variable (number of words in the problem statement) apparently was more important in the upper grades than in the lower grades. In this study three forms of a verbal problem set in which the number of words in the problem statements were systematically varied were administered to classes of students in Grades 4–9. Using regression analysis, the investigator found that although the length variable did not measure a significant amount of variance between two of the forms, with the third it did.This study was begun while the author was a staff member of the Institute for Mathematical Studies in the Social Sciences at Stanford University. The research was partially supported by National Science Foundation grant G18709.     

Problem length as a structural variable in verbal arithmetic problems

Of five structural variables that in previous studies accounted for a significant amount of the observed variance in the error rate in verbal arithmetic problems, the length variable (number of words in the problem statement) apparently was more important in the upper grades than in the lower grades. In this study three forms of a verbal problem set in which the number of words in the problem statements were systematically varied were administered to classes of students in Grades 4–9. Using regression analysis, the investigator found that although the length variable did not measure a significant amount of variance between two of the forms, with the third it did.This study was begun while the author was a staff member of The Institute for Mathematical Studies in the Social Sciences at Stanford University. The research was partially supported by National Science Foundation grant G18709.     

Problem length as a structural variable in verbal arithmetic problems

Of five structural variables that in previous studies accounted for a significant amount of the observed variance in the error rate in verbal arthmetic problems, the length variable (number of words in the problem statement) apparently was more important in the upper grades than in the lower grades. In this study three forms of a verbal problem set in which the number of words in the problem statements were systematically varied were administered to classes of students in Grades 4–9. Using regression analysis, the investigator found that although the length variable did not measure a significant amount of variance between two of the forms, with the third it did.     

What students think when teachers get upset: Fundamental attribution error and student‐generated reasons for teacher anger

Using a sample of college students (N = 301), this study examined students' attributions about and explanations for teachers' expressions of anger in the classroom. These displays of anger were evaluated based on the extent to which they were aggressive (e.g., Distributive or Passive) or assertive (e.g., Integrative). Consistent with the fundamental attribution error, students assigned internal attributions to teachers who used Distributive Aggression (e.g., yell and scream) and Passive‐Aggression (e.g., show anger with cold looks) to a greater extent than teachers who were Assertive (i.e., calmly discuss the problem with the students). When students were asked to identify why they thought their teacher was angry, the overwhelming majority of reasons involved student‐related problems. In fact, the most frequently cited reason was Student Misbehaviors followed by Lack of Student Effort. Surprisingly, students acknowledge that something they did triggered the teacher's display of anger; however, consistent with fundamental attribution error, students still attributed the teacher's expression of anger to internal causes. The implications of these findings for negative emotional expressions in the instructional context in particular and for teacher‐student relationships in general are discussed.     

Addition and multiplication: Problem-solving and interpretation of relevant data

This study constitutes a first step towards the elaboration of a method for intervening in the processes of solving concrete mathematical problems, based on the processing of expressions often included in the statement of addition and multiplication problems presented to second-cycle elementary students (ages 9 to 12). Forty-eight students took part in the experiment: the 29 subjects of the experimental group were divided into small groups of about 5 subjects in each and had to perform various learning exercises. The aim of these exercises was essentially to improve skills in analyzing and processing certain expressions frequently included in the statements of addition and multiplication problems. The effect of these learning exercises on problem-solving was evaluated by a problem-solving pre-test and post-test presented to the subjects in both groups. The learning exercises helped significantly to improve the problem-solving performance of subjects in the experimental group. Analysis of the verbal productions of the subjects in this group during the learning exercises revealed certain factors related to the effectiveness of the method of intervention proposed in this research.     

An evaluation of the Touch Math method for teaching addition to students with learning disabilities in mathematics

The present study was designed to determine if children with learning disabilities in mathematics could be taught three‐row, double‐digit addition problems using a dot‐notation method. Three children with learning disabilities in mathematics were selected for the study. Prior to the intervention, these students employed a combination of count‐all and count‐on strategies when solving addition problems and relied on concrete referents such as fingers or tallies. A multiple‐probe design was used to evaluate the effectiveness of the intervention. The experiment consisted of a teaching phase where students learned to count the dots on numbers 1 to 9 in a specified pattern, and an intervention phase where students progressed through nine levels of addition problems. Results indicate that the three subjects were able to learn and apply the dot‐notation method successfully, and to retain the method from one‐and‐a‐half to four‐and‐a‐half months after completing instruction.     

Undergraduate students searching and reading Web sources for writing

With the Internet-evoked paradigm shift in the academy, there has been a growing interest in students’ Web-based information-seeking and source-use practices. Nevertheless, little is known as to how individual students go about searching for sources online and selecting source material for writing particular assignments. This exploratory study focuses on the Web-based searching and reading practices of a group of undergraduate students at a university in Hong Kong in preparing their end-of-semester written assignments. The data drawn upon included interviews and the students’ process logs and their notes from reading. The study revealed that the students employed a range of search engines to conduct online research, they skim-read and read around search terms to select sources and source content, and they took indexical notes to document their decisions over citations for their essay. The paper ends by pointing out some pedagogical implications of the study and suggesting in-depth case studies as an avenue of further research.     

The Design Brief as a Creativity Catalyst in Design Education: Priming through Problem Statement

The design brief informs particularly the first phases of the design process; however, there are very limited studies on its role and functions. The current study proposes a framework that relates problem statement types in a design brief to creative outcomes by promoting the priming effect, which is a cognitive phenomenon describing the ways individuals behave accordingly to the way they receive a stimulus. The claim is that the brief has the potential to stimulate creativity and influence the type of outcomes by priming the design students using the problem statement. An experiment was conducted in which two groups of design students generated sketches in response to two types of problem statements (in noun and verb formations) in similar design briefs. The problem statements in verb formation were found to lead to a higher number of sketches containing more novel and flexible, yet less realisable ideas. The results support the contention that the design brief and the type of problem statements have the potential to act as a catalyst for creativity early in the design process.     

中西方英文个人陈述的对比研究——从体裁分析看文化差异

尽管个人陈述在学生申请留学的过程中扮演着重要角色,却很少受到关注。为探讨中西方英文个人陈述的差异,运用体裁分析理论,对中国学生和英语本族语学生的英文个人陈述进行对比分析,发现两者在语步结构和语言特征两方面存在有明显的文化差异。旨在帮助中国学生进一步了解个人陈述的体裁特征,写出更加地道的英文个人陈述。     

Fostering empirical examination after proof construction in secondary school geometry

In contrast to existing research that has typically addressed the process from example generation to proof construction, this study aims at enhancing empirical examination after proof construction leading to revision of statements and proofs in secondary school geometry. The term “empirical examination” refers to the use of examples or diagrams to investigate whether a statement is true or a proof is valid. Although empirical examination after proof construction is significant in school mathematics in terms of cultivating students’ critical thinking and achieving authentic mathematical practice, how this activity can be fostered remains unclear. This paper shows the strength of a particular kind of mathematical task, proof problems with diagrams, and teachers’ roles in implementing the tasks, by analysing two classroom-based interventions with students in the eighth and ninth grades. In the interventions, the tasks and the teachers’ actions successfully prompted the students to discover a case rejecting a proof and a case refuting a statement, modify the proof, properly restrict the domain of the statement by disclosing its hidden condition, and invent a more general statement that was true even for the refutation of the original statement.     

Representation and Process in Learning Environments for Mathematics: A Commentary on Three Systems

Three computer‐based systems for teaching arithmetic and algebra are discussed. The systems embody several pedagogical tactics: To provide students with augmented repre‐sentations that reveal the structure of problem solutions; to make mathematical symbols meaningful by giving students concrete referents for those symbols; to provide students with enriched feedback about the consequences of their mathematical operations; and to adapt instruction to the cognitive processes of the students. Weaknesses in the three systems are discussed and two general problems, called complexity trade‐off and scaffold removal, are put forward as possible explanations for why the systems are not more effective. The alternative view that mathematics is difficult because it requires abstract thinking is outlined and some of its implications discussed briefly.     

On Discerning Critical Elements, Relationships and Shifts in Attaining Scientific Terms: The Challenge of Polysemy/Homonymy and Reference

Words with well-known meaning in colloquial language often make up an educational challenge when introduced as terms with formal scientific meaning. New connections must be established between the word, already constrained by existing meaning and reference, and the intended formal scientific meaning and reference. A two-dimensional semantic/semiotic analysing schema (acronym 2-D SAS) has been developed to clarify a given word/term in a structured mode both according to non-formal senses and referents and formal scientific meaning and referents. The schema is constructed on ideas from semantics, semiotics and history and philosophy of science. The approach is supposed to be a contribution to make a fine-gained analysis of the structure and dynamics of conceptual change. The role of referents and referent change in conceptual change is highlighted by analysing the character of the recurrent mix-up of the terms heat and temperature among students at different educational levels.     

Changing Demands on Counseling Centers:

Mounting pressure on campus administrators to cope with students who disrupt the campus living/learning environment has resulted in counseling centers being increasingly drawn into the management of student behavior. Underlying this trend are the naive assumptions that counselors have the ability to predict future behavior and control disruptive students through psychotherapy. These myths not only fail to produce expected results, but threaten to undermine college counseling as an effective resource for behavior change. Counselors must not only work to dispel these myths, but help faculty/staff find more effective ways to work with problem students. This process requires a clear statement of the expectations of student behavior and a broader acceptance among faculty/staff of the responsibility for confronting disruptive students with the consequences of their behavior.     

Worked Examples Versus Non‐goal‐specific Problems: a test of schema development in geometry

A multiple baseline across subjects experimental design was used to compare the effects of a teaching programme designed to enhance schemata acquisition with that of worked examples, traditionally used to teach geometry to high school students. In the first treatment, students were guided to form their own personal, independent schema through the use of non‐goal‐specific questions, that is, questions that did not ask to find a single, specific unknown. The second treatment introduced students to solved examples of problems asking for specific values. Following exposure to one or other of the treatments, measures were obtained of students’ success in problem solving, the time taken and the processes used. Results show that students in both groups had gains in the number of problems solved following intervention, with those exposed to the non‐goal‐specific procedure showing greater rates of improvement and greater efficacy in their problem‐solving strategies. These findings are discussed in terms of their implications for a schemata acquisition and problem‐solving hypothesis.     

Examining How Activity Shapes Students' Interactions While Creating Representations in Early Elementary Science

It is common practice in elementary science classrooms to have students create representations, such as drawings, as a way of exploring new content. While numerous studies suggest the benefits of representation in science, the majority focus on specific, canonical representations, such as graphs. Few offer insight or guidance regarding how teachers might effectively incorporate ad hoc, non-normative student-generated representations in their curricula. This study addresses this gap by detailing the relationship between two designed activities—one that supported more open-ended engagement with referents and the other that promoted a synthesis of referents—and the representational products that students generated as a result. We present data from a mixed age classroom (ages 6–9, N?=?32) as students depicted their understanding of loggerhead sea turtles. Findings indicate that students performed better when working alone in the open condition and in collaborative dyads in the synthesize condition. These results suggest that it is necessary to unpack how mediating factors (such as students' cooperative strategies, facilitator feedback and materials used) align, to support or inhibit students' representational activities.     

DV-Hop定位算法改进研究

传统DV-Hop定位算法中,在估算未知节点与锚节点的距离时,只采用距离其最近的一个锚节点的平均每跳距离,因而存在较大的定位误差.为了解决该问题,本文在传统DV-Hop算法基础上,同时考虑多个锚节点的平均每跳距离,根据每个锚节点的平均每跳距离误差以及跳数对未知节点的平均每跳距离进行加权处理,使其更接近实际值,未知节点与锚节点之间的估算距离更加准确,从而减少定位误差.仿真实验证明,在相同的网络环境下,改进算法定位精度明显高于传统DV-Hop定位算法.