摘要
在过去几十年中，语言教育有一种越来越明显的总体趋势，即不再强调语言本身，而是强调将语言作为一种交际工具。依托式教学（即以学科内容为依托的语言教学）作为这种趋势的直接产物，已日渐用于各种教学环境，成为提高学生语言能力的一种有效方法。依托式教学将二语/外语与学科内容结合起来，通常被认为是当代二语/外语教学法中最有代表性的贡献之一。
依托式教学有深厚的理论基础。首先，教育学理论——包括体验式学习理论及建构主义理论，为依托式教学提供了有力支持。其次，依据功能语言学的观点，语言是表达功能意义的途径，语言学习不仅要学习语言的“用法”，更要学习语言在现实环境中的“使用”。最后，第二语言习得理论认为自然语言习得产生于有上下文的语境，学习者通过接触大量的语言输入习得语言。依托式教学将学生学习的重点放在有意义的内容上，而不是语言本身，为学生提供一个语言环境，使学生能进行有意义的交际活动，从而有效地促进语言习得。在依托式教学中所使用的知识框架理论（Mohan 1986）、任务教学理念以及“6- T”教学原则（Stoller ＆ Grabe 1997）均有助于学生习得目标语。
依托式教学已经在全世界范围内以丰富多彩的形式广泛用于各种教学场景。人们已经通过许多实证性研究证明依托式教学对提高学生语言水平的作用，这种研究在英语为第二语言（ESL）的环境中尤为多见。然而，在以英语为外语（EFL）的环境中，尤其是在中国大学英语教学环境中开展依托式教学研究的实例却很少报道。当前，中国高校正在深化大学英语教学改革，目的是提高学生的英语综合应用能力，而依托式教学将语言学习与学科内容学习结合在一起，能够在提高学生的学科知识水平的同时提升其语言能力，可成为实现大学英语教学改革目标的一种途径。
本研究旨在考察大学英语教学环境中依托式教学对大学英语学习者英语水平以及学习者个人因素的影响，同时也将研究依托式教学中“教”和“学”的过程。参加本项准实验研究的被试是来自国内某综合性大学的370名非英语专业学生。他们年龄相近，所受教育背景相仿，实验开始时刚升入大学二年级，并均已通过全国大学英语四级考试。研究中的实验组有185名学生，来自中文、教育和材料专业，他们学习以学科内容为依托的语言教学课程；对照组有185名学生，来自生物、食品和机电专业，仍学习常规大学英语教学课程。为进一步验证依托式教学的效果，实验组根据学生实验前的英语水平分为高分组（56人）、中间组（73人）和低分组（56人）。本研究采用定量研究和定性研究的方法，定量研究包括一系列以测试为基础、以结果为目标的实验，以确定依托式教学对学生英语水平、英语学习动机、焦虑感、学习策略以及评判性思维的影响；定性研究包括对依托式教学中的学习环境和学习过程的观察和分析，此研究以课堂教学研究为基础、以教学过程考察为目标。
本教学实验研究从2008年9月开始，到2009年7月结束，历时一学年。在教学实验前，实验组和对照组学生均已参加了英语水平、英语学习动机水平、英语学习焦虑感水平、英语学习策略以及评判性思维能力方面的测试，结果显示两组学生在上述测试中均无显著差异。在实验过程中，研究人员对两组学生进行了课堂观察，并对教学过程进行了记录。在实验中和实验结束时，两组学生再次参加了与实验前检验项目相同的测试，并在实验结束时接受了有关两种教学方法的调查。
本研究对收集到的数据采用了多元统计分析，以确保对大学英语教学环境中依托式教学效果的检验更为系统、有效。以下为研究发现。
1．实验组学生总体动机水平比对照组学生高，并且更多的学生表现出融入型动机。具体说，实验组学生比对照组学生有更强的学习英语的愿望，不过，两组学生在动机强度（努力程度）方面没有显著差异。在实验组内，各种语言水平的学生，其英语学习动机水平都较实验前有所提高，但低分组学生的学习动机提高程度不显著。
2．在实验结束时，实验组和对照组学生在总体的焦虑感及交际恐惧感方面有显著差异，实验组学生在用英语进行交流时更有信心。但在考试焦虑和害怕负面评价方面两组学生无显著差异。在实验组内，高分组和中间组学生的英语学习焦虑感从实验开始到实验结束呈显著降低的趋势，而低分组学生在第一个学期的教学实验中焦虑感没有显著降低，但适应依托式教学环境后，第二个学期其焦虑感有了明显降低。
3．尽管在教学实验开始时，实验组和对照组学生在英语学习策略使用上处于同一水平，但实验结束时，依托式教学班级的学生比常规大学英语教学班级的学生使用学习策略更频繁，在学习英语的过程中更有自主性和自我管理意识。在依托式教学班级中，学生经常使用元认知策略和补偿策略。在实验组内部，高分组和中间组学生在总体的英语学习策略使用上都取得了巨大进步，而低分组学生在第一个学期教学实验中其英语学习策略使用能力没有显著提高，到第二个学期有了明显进步。
4．经过一学年的依托式教学实验后，实验组学生总体的评判性思维能力（包括辨认假设能力、演绎能力、归纳能力）优于对照组。在实验组内，各种不同语言水平的学生，其评判性思维能力在教学实验中都有提高，但因学习动机、学习策略及语言水平的影响，他们的评判性思维能力提高的幅度有很大差异。
5．在本研究中，依托式教学模式和常规的大学英语教学模式都有助于学生总体英语水平的提高，但与常规大学英语教学班级的学生相比，依托式教学班级的学生能更大幅度地提高他们的总体英语水平，表现出更好的接收性语言技能，如阅读与听力能力。此外，实验组学生在使用英语进行交际的能力以及口语技能方面都比对照组学生强。然而，依托式教学班级中的学生在词汇能力和写作技能上虽有提高，但与常规大学英语教学班级中的学生相比不呈显著差异。另外，在依托式教学班级中，高分组和中间组的学生，其语言水平在整个实验过程中均有显著提高，而低分组的学生，其语言水平的提高幅度不如其他两组学生。
此外，依托式教学模式给学生提供了一个良好的学习环境以促进语言习得。在依托式教学课堂中，语言输入多种多样且真实。学生积极参与学习过程，通过完成各种学习任务和解决现实问题来提高英语水平，同时增加学科知识和提升思维技能。
因此，在大学英语教学环境中实施依托式教学能有效提高大学英语学习者的英语水平，帮助他们学习学科知识。该教学模式可以作为众多大学英语教学方法中的一种选择，尤其是在学生通过大学英语四级考试，达到《大学英语教学大纲》规定的最低要求以后。在依托式教学中，学生能接触大量真实的语言输入，在学习学科内容和完成学习任务过程中有更多的机会练习各种语言技能，从而提高他们的英语实际应用能力。如果在大学英语教学环境中，依托式教学的一些条件（如教师资质及开展依托式外语教学前学习者的语言水平）能够得到满足，该教学方法则能体现其他方法所没有的优势，帮助以英语为外语的中国大学英语学习者提高英语水平、思维能力和文化素养，实现《大学英语课程教学要求》中的教学目标。
关键词：依托式教学 动机 焦虑感 学习策略 评判性思维能力英语水平
Abstract
A general movement in language teaching, away from putting emphasis on the language itself towards a more focused emphasis on teaching the language as a tool in communication, has become evident over the past few decades. As a direct consequence of this trend, CBI（Content-based Instruction）has become increasingly popular as an effective means of developing learners' linguistic ability in a great variety of educational contexts. CBI is a method of teaching second/foreign languages that integrates language instruction with instruction in the content areas. CBI is generally accepted as one of the most representative contributions to contemporary second/foreign language pedagogy.
CBI possesses a solid theoretical foundation. In the first instance, general educational theories, including experiential learning theory and constructivism, provide support to CBI. Secondly, according to the functional view of language, the language itself is a vehicle for the expression of functional meaning; learning a language is not only learning its“usage”, but also its“use”in real life situations. Finally, theories of second language acquisition indicate that natural language acquisition occurs in a real life context, and learners can more effectively acquire the language by being exposed to a significant amount of input. CBI provides a context in which meaningful communication can occur and leads to efficient language acquisition. Second language acquisition increases with content-based language instruction because learners absorb the language most proficiently in an environment where there is an emphasis on relevant and meaningful content rather than on the language itself. The Knowledge Framework（Mohan 1986）, the task-based approach and the Six-T's approach（Stoller ＆ Grabe 1997）all contribute to learners' acquisition of the target language in CBI.
CBI has been widely used in an extensive number of educational settings worldwide in a variety of models. Numerous empirical studies exist to demonstrate the efficacy of CBI in developing learners' language proficiency, especially in the ESL settings. However, very few reports on empirical studies on CBI in the EFL context exist, especially in the Chinese College English context. Currently, universities and colleges in China are deepening the reform of College English teaching with the purpose of developing EFL learners' ability to use English in an all-round way. CBI can be taken as a possible way to attain the goal of College English teaching reform for it integrates language learning with content and aims to enhance learners' disciplinary knowledge as well as language proficiency.
The purpose of this study was to examine the impact of CBI on the development of Chinese EFL learners' English proficiency and their individual factors in the College English context. At the same time, the study investigated the teaching and learning process with the content-based approach. The participants involved in the study consisted of 370 non-English majors from a comprehensive university in China with similar ages and educational backgrounds, who were in their third academic semester and had passed the CET-4. The treatment group included 185 participants who were majoring in the Chinese language and literature, education and material science, and they were taught with a content-based approach. The control group was composed of 185 participants majoring in biology, food science and electrical engineering and the students in this group were kept in the regular College English class. In order to further reveal the efficacy of CBI, the learners in the treatment group were divided into 3 subgroups: H-group（56 students）, M-group（73 students）and L-group（56 students）based on their performance on the English proficiency pretest prior to the experimental teaching. Both quantitative and qualitative methods were employed in this research. The quantitative study contained a series of test-based and product-oriented experiments, examining the effects of CBI on learners' English proficiency, motivation to learn English, anxiety in learning English, learning strategies and critical thinking skills. The qualitative study explored the learning context and learning process under CBI by using classroom-based and process-oriented research methods.
The experimental teaching program lasted one academic year, commencing in September, 2008 and extending to July, 2009. Prior to the teaching program, participants in both the treatment group and the control group took the pretest in English proficiency, motivation to learn English, anxiety in learning English, learning strategies and critical thinking skills and it was revealed that there were no significant differences between the two groups in the aspects as listed above. In the course of the teaching experiment, the two groups of learners were observed in the classroom and the teaching processes were recorded. In the middle and at the end of the experimental teaching program, participants in both the treatment group and the control group took the post-tests in terms of aspects similar to the pretest, and they were interviewed with regard to the two teaching methods.
Multivariate statistical analyses were conducted to process the collected data to guarantee a more unitary examination concerning the efficacy of content-based instruction in the Chinese College English context. It was found that:
1．Learners in the CBI program generally demonstrated a stronger motivation to learn English than those in the regular College English program and more learners in the CBI class had integrative motivation. To be specific, the learners in the treatment group had a much stronger desire to learn English than their counterparts in the control group, but no difference was observed between the two groups of learner in motivational intensity in learning English by the end of the experimental teaching program. Moreover, learners with different English proficiency levels in the CBI class under study enhanced their motivation to learn English, although the L-group learners didn't develop their motivation significantly.
2．At the end of the experiment, learners in the two groups demonstrated significant differences in their overall anxiety in learning English and communication apprehension, and learners in the treatment group had more confidence in their use of English to communicate with others. However, the two groups did not show any differences in the aspects of testing anxiety and fear of negative appraisal. With regard to the learners in the treatment group, the H-group learners and M-group learners demonstrated a significantly lower anxiety in learning English since the commencement of the teaching experiment, while the L-group learners didn't decrease their anxiety significantly in the first semester and a change was not observed until they became acquainted with the learning context of CBI in the second semester.
3．Although learners in both the treatment group and control group had the same level in using learning strategies when the experimental teaching program commenced, learners in the CBI class used English learning strategies more frequently and tended to be more autonomous and self-regulated in learning English than those in the regular College English class at the end of the program. The English learning strategies frequently used by the learners in the CBI classes were metacognitive strategies and compensation strategies. In the treatment group, learners in the H-group and M-group remarkably increased their overall use of English learning strategies. However, learners in the L-group did not show any significant progress in their use of English learning strategies during the first semester and improvement only became evident when they joined the CBI classroom in the second semester.
4．After having been educated in the CBI context for one academic year, learners in the treatment group outperformed those in the control group in terms of overall use of critical thinking skills, namely assumption identification, induction and deduction. All the learners of different English proficiency levels in the treatment group developed their critical thinking skills during the teaching experiment, but great variance could be found in their progress of using critical thinking skills due to differences in their learning motivation, learning strategies and English proficiency.
5．Both the CBI program and the regular College English program helped to enhance the general English proficiency of learners in this study. However, learners in the CBI class developed their general English proficiency at a faster rate and demonstrated a higher proficiency in receptive skills（including reading and listening）than their counterparts in the regular College English class. In addition, learners under CBI had a greater proficiency in using English in real life communication and had developed better speaking skills than those learners in the regular College English class. Although learners in the treatment group did improve their vocabulary and English writing skills, there was no significant difference in these two aspects between the treatment group and the control group. In the treatment group, learners in the H-group and M-group developed their English proficiency significantly while learners in the L-group failed to make as much progress as those in the two subgroups mentioned above.
In addition, the CBI model provided a beneficial learning context which facilitated language acquisition. Input in the CBI class was of great variety and authenticity. Learners in this context took an active role in the learning process and they improved their language proficiency, acquired access to the subject matter and upgraded their thinking skills by completing various tasks and solving real life problems.
A conclusion can be drawn that CBI in the College English context is an effective way to develop Chinese EFL learners' English proficiency and in the process helps them to gain knowledge concerning the subject matter. It could be adopted as an option among the various language teaching methods in the College English context, especially after the college English learners have passed the CET-4 and have met the basic requirements of the College English Syllabus. Learners in the CBI model are exposed to a significant amount of authentic input and motivated to learn both content and language, and they have more opportunities to practice the target language skills when they learn the subject matter and complete various tasks, which enhances their ability to use English in real life situations. When a number of conditions for CBI（e. g. the teacher's qualifications and learners' language proficiency prior to CBI）are met in the College English context, the CBI approach can display important advantages over other teaching methods in helping Chinese EFL learners to develop their English proficiency, thinking skills and cultural quality, and to achieve the goals stated in the College English Curriculum Requirements.
Keywords: CBI; motivation; anxiety; learning strategies; critical thinking skills; English proficiency