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On Computer Assisted Language Learning (CALL) and Change of Teachers’ Role

In recent years, being a fast developing method in language learning area, the Computer Assisted Language Learning (CALL) is widely used in language learning in the world. CALL provides a totally different new mode for language learning. Hence, it increases quality and efficiency of language learning. Through perfect combination of contents, process and computer-assisted, CALL pays attention to stimulate students to learn languages with the assist of computer and pursues best learning results. With the brief introduction of CALL, the thesis fully explores teachers’ roles in the Computer-Assisted Language Learning. With the new achievements in Computer Science, Information Technology and Psychology, CALL will be closely connected with Computational linguistics to increase the intelligence of language learning system.


Introduction
With the rapid development of modern information technology, the application of technology in the education area is increasingly wider and deeper, especially the connection of Internet and language learning. In the College English Curriculum Requirements (2004 issued for trial implementation), it states "the objective of College English is to develop students' ability to use English in an all-round way, especially in listening and speaking." "One of college English teaching objectives is to develop students' autonomous learning ability, and that important symbols for successful teaching reform are the formation of students' individualized learning methods and the development of students' autonomous English learning ability." "College English is not only a language course that provides basic knowledge about English, but also a capacity enhancement course that helps students to broaden their horizons and learn about different cultures in the world." "Colleges and universities should remold the existing unitary teacher-centered pattern of language teaching by introducing new teaching models with the help of multimedia and English technology. The new model should be built on modern information technology so that language learning will be free from the constraints of time and place and geared towards students' individualized and autonomous learning."

Definition of CALL
Computer Assisted Language Learning (CALL) has been applied in language education since the 1960s. It refers to any process in which learner improves his or her language competence by using a computer. IOP Conf. Series: Earth and Environmental Science 632 (2021) 052049 IOP Publishing doi:10.1088/1755-1315/632/5/052049 2 And Levy (1997) defines CALL as "the search for the study of applications of computer in language teaching and learning". This definition is widely used by scholars and researchers nowadays. And the developing integration of computer and English with foreign language teaching and learning not only relies on technology development but also depends on the transformation in education theory. Based on this feature, Wars Chaucer and Healey (1998:57) divided the history of CALL into three main stages, including behaviorist CALL, communicative CALL, and integrative CALL. Behaviorist CALL, which was prevalent in the 1950s to the 1970s in the United States, was on the basis of behaviorist theories of learning (Wars Chaucer, 1996). According to this school, the process of language learning was a kind of habit formation, which means learner should acquire language through repetitive practice including vocabulary, grammar, drill programs and so on. And the computer used here mainly served as instruments to deliver learning materials to learners, because its ideal function in presenting repeated drills and practices to individual without feeling tired and bored. Drill and practice courseware is based on the model of computer as tutor (Taylor, 1980), and the most famous tutorial system in this period is PLATO which is composed by central computer and terminals. This system included vocabulary and grammar drills as well as translation practices at different levels. But because of the theoretical development in pedagogy and the employment of the microcomputer, Behaviorist CALL was undermined in the late 1970s and replaced by a new phase of CALL.

The Theoretical Basis: Constructivism
In recent years, with the popularity of computer and the growth of the Internet, constructivism theory came back to taken seriously by people. According to constructivism theory, the new knowledge is obtained on the basis of personal original experience, original knowledge, and through the interaction activities with the environment. The learning process is the people's cognitive thinking activity actively building process. Learners are the active building person of knowledge, rather than passive recipients of the information. The main idea of Constructivism theory is: learners are not passively accept information stimulation: it is a learning process where students use the original cognitive structure, namely, knowledge and experience based on their own needs, interests, hobbies to conduct the active choice, processing and handling of external information.

The Necessities and Advantages of CALL
The traditional teaching process is characterized by teachers' explanation and interpretation, but this method often lacks the vividness, failing to arouse students' enthusiasm for study. While computerassisted language teaching gains more popularity as it's practical, systematic, flexible and changeable. Firstly, it enables students to learn more knowledge in a more relaxing and joyous way. Secondly, as this method requires students' involvement and participation in a relaxing learning environment, it's convenient for teachers to discover students' potentials and motivate their study enthusiasm and initiative from various perspectives, therefore making up the shortage of visual in traditional teaching. Thus, the computer-assisted language teaching is advisable to be applied in teaching for the purpose of achieving good teaching results and improving teaching efficiency.

To stimulate students' interest in language learning.
Interest is the premise to obtain knowledge and acquire skills. Interest is not innate, but motivated by novel and unique outward objects. The multimedia technology shows information that can be seen and heard, and with lively diversified forms. This multi-level expressive force and diverse sense provokement is also a necessary in English teaching. A positive mental experience would produce in this kind of environment and rapidly turned a thirst to knowledge. The information content students get would be more than single listening to the teacher's lecture, and it is more beneficial to the maintaining and transferring of knowledge.

2.3.2.
To provide diversified external stimulation. The main task of College English Teaching is to culture students' abilities to communicate with others, only organs like the eyes, ears, mouth, brain cooperate well can be best accomplished the culture of abilities of listening, speaking, reading and writing. Moreover, students get many sense organs participated in the learning process, namely to focus attention on three: trust your eyes, ears, mouth and mind, so as to avoid the distraction and further improve the efficiency.

To increase classroom capacity.
Along with the enhancement of social informatization, the information that teaching need to transfer is more and more, so do the science knowledge students need to master. Therefore, barely depends on the traditional teaching method can not meet the needs of modern society for talents. By using computer-assisted teaching we can reduce the time wasted in writing on the blackboard, increase classroom capacity. Furthermore, through modern information technology we can make some knowledge that hard to grasp directly presented to students, in this way to deepen their impression and understanding, thus improve the teaching quality.

To cultivate students' consciousness of communication.
Due to the difference in the aspects of thinking, value and social customs, our students having certain difficulties in learning English and using it to communicating itself, while in actual learning they often merely pay attention to the study of knowledge points and ignore its concretely application. For that reason, most students can learn the fixed, isolated knowledge from the prototype examples and the materials in the text, but the ability to migrate knowledge to the real life is poor. They always surrendered when run into the different problems in distinct situations in reality. Nevertheless, with computer assisted teaching we can simulate situations in real life, thus shorting the distance between teaching and reality, providing them opportunities to communicate in English, stimulating their desire to express their opinions. Undoubtedly this kind situation study to some extent promoted the study migration, thus improving students' communication skills among English communication activities.

Position-setting of Teachers' Role in CALL
The multimedia system with computer as its core possesses a great advantage in college English teaching. It can make English audio-visual teaching activities from the traditional teaching mode transforms to the stereo teaching mode. It can build English atmosphere, fully mobilizing the enthusiasm of the students learn English, get students participate in English teaching. At the same time, increasing the information density teacher provided in college English class, develop student's field of vision and cognitive, thus carrying out the quality education that students as the main body, the teacher as the lead. At present, the integration of information technology and curriculum English is still on the stage of exploration and research, which is forward on the basis of traditional classroom. It takes teaching modes combining classroom teaching and English teaching software that operated in campus English as main developing direction. The role of language teacher can be interpreted in different ways, here mainly focus on the four basic roles-Learning Promoter, Organizer of Class Activities, Designer and Enquirer of Information Resources and Monitor and Assessor.

Students' Learning Promoter
The teacher's behavior in class is extremely important for students. If teachers can't inspire students' interest, then the student-centered class will be back to the traditional teaching mode again. So teachers should be asking more questions, arousing the students' participation and creativity: praise students much more and implement the rewarding mechanism; create dialogue scenes; communicate with them, ask about their ideas and discuss with them; good at stimulate students' learning talents with persuasive methods. Teachers should not only impart knowledge, but also teach students how to learning independently.
Teachers can use different methods to improve student learning. Here we merely focuses on setting up situation and using multimedia in language learning. Professor bloom said, a successful lesson lies mainly set up situation in the class, because this is the only way students have the opportunity to apply their language materials to real scene. Set up situation is one of the most important features of constructivism class room. And it can promote students' imagination, and arouse their interest. In this IOP Conf. Series: Earth and Environmental Science 632 (2021) 052049 IOP Publishing doi:10.1088/1755-1315/632/5/052049 4 activity, the main task of the teacher is to bring students into the situation successfully through methods like made dialogue, provide images, played film clip, role playing and so on. To complete this task, the teacher must prepare lessons well, and freely to use all kinds of auxiliary material. In class, teacher should help students study in a pleasant atmosphere and let them get active.

The Organizer of Class Activities
It is believed that besides Guide and Facilitator, another important teachers' role in cultivating learner autonomy is organizer. Organizer's responsibilities consist of three aspects including: first, Curriculum management, which means teachers' transformation from the executor of curriculum to designer and developer. As we know, in traditional education, although being the center of teaching activities, teachers are only showers or executors of course content. But with the application of CALL, the curriculum is no longer being carrier of certain knowledge system, but a developing process of exploring knowledge. So teachers have to design and develop characteristic curriculum according to the needs of learners. Second, classroom management refers that teachers should organize appropriate activities and provides suitable teaching arrangements to students. Third, device management, which ask the teachers to apply computer assisted instruments in teaching and develop instructional software.

The Designer and Enquirer of Information Resources
Using multimedia is one feature in language learning. In the auxiliary multimedia, the students can find problems and take initiative to solve the problems. Students become the center of learning, and teachers would stand by the side, as guide and assistant. The teacher should also be the designer and enquire of information resource. In a multimedia language class, in order to arouse and maintain the learning interest of students, teacher should provide them with various information resources, doing a lot of work such as search, edit, and settle. Besides, with the help of multimedia, students can use E-mail, online discussions, online writing to deepen their learning, to get more knowledge. Such knowledge is dynamic, and can change with the experiences. Therefore, teachers need to master the multimedia technology and related communication technology, learn to search for information in the internet, sort out the gathering information to make them serve for class teaching services effectively.

The Monitor and Assessor
Computer-assisted class teaching requires teachers to conduct certain monitoring on students' learning activities so as to know whether they are study effectively, whether meet obstacles and problems need help in the learning process, and the study results. Finally, at the end of the study, teachers will testing them and give an effective evaluation to students' learning. Although during learning process, students will make rough evaluation about their own learning effect, but the conclusion they made maybe short of accuracy because of the limited knowledge. According to this reason, teachers should take charge of this issue. On the other hand, making evaluation about students' learning outcomes and strategies will help teachers to grasp the implementation of teaching programs effectively and make adjustment about the teaching schedule as well as teaching plan if necessary.
To be a qualified assessor, teachers should pay more attention to students' learning process, especially to their learning habits and attitudes which can not be valued by testing but by observing. Meanwhile, we have to establish a comprehensive and rational evaluation system, including level test and mid-term test, peer assessment as well as self-assessment, all of which will help students to monitor their learning process and get valuable suggestion to recover their shortage.

Conclusion
Information technology and language curriculum integration are still in the study phase, while the teacher's role and function have changed a lot. Although most educational services have established multimedia classroom, many of them are not really effective in language learning. In order to bring CALL into full play, teachers should also change teaching concepts promptly from the purely knowledge addresser, language importer, and demonstrator to designers of teaching task, organizers of learning IOP Conf. Series: Earth and Environmental Science 632 (2021) 052049 IOP Publishing doi:10.1088/1755-1315/632/5/052049 5 activities, prompters of the students' study, and the monitor and assessor of teaching. All in all, on CALL circumstances, with the assist of computer and Internet, language teachers should set up idea learning environment of constructivism for students.