A great number of English as a Foreign Language (EFL) learners are most likely to make no perceptible progress in the process of learning language despite their efforts and practice. This is known as Plateau Phenomenon (Richards, 2008), which occurs most evidently when learners reach the upper intermediate level. According to Richards (2008), plateau refers to the problems that EFL learners face as they pass through the intermediate to the advanced levels of language proficiency where they seem to have hit a plateau in learning English and come to the understanding that they are not improving in their learning. Much in the same way, Shormani (2013) contends that EFL learners mostly hit the language learning plateau while passing from intermediate to advanced level. Plateau of learning is a terminology of educational psychology. In fact, plateau implies that one comes to another period of little or no further progress (as seen by a flat part on a learning curve) in study after making rapid progress initially (Xu, 2009). On the learning curve, learners make big improvements very quickly; and then the acceleration of their progress dramatically slows down (Rowntree, 1981). This phenomenon is commonly observed in EFL learning. It is during this period of time that many EFL learners experience anxiety which impedes their further efforts in progressing in learning English (Yi, 2007).
The good news is that the phenomenon of language learning plateau is considered as a temporary cessation in learning development of L2 learners who are at the transition phase of going to a more advanced level after reaching a certain degree (Shormani, 2013). Similarly, Richards (2008) and Yi (2007) state that the language learning plateau in foreign language learning development is not permanent and can be overcome under certain pedagogical procedures. According to Yi (2007), at the very beginning, every input in target language is new and challenging for learners. Therefore, they are highly motivated to learn and use these new inputs by trying to perform in the target language. Throughout this period, the learners tend to constantly learn new linguistic items because, high motivation and curiosity save them from blocking the production. As a result, the learners’ progresses are clear and prominent till a certain degree that they feel themselves satisfied with their cumulative knowledge.
In the Iranian EFL setting, a number of language learners who enroll in language institutes start from elementary levels and undergo the instruction as is directed by the course books which have been chosen by the institutes. Mainly, in the beginning stages, it is noted that most learners tend to get the most of what is instructed regarding the basic vocabulary, structures, and other linguistic components. Therefore, at this level, the majority of the materials presented by the teacher is well absorbed by the learner, which results in a high correlation between the requirements of the course objectives and the gains of the learner. However, it has been noted by experienced language teachers that this acceleration decreases as the course level increases (Yi, 2007). In other words, the amount of attainment of language competence dramatically drops as learners enter upper intermediate and advanced levels. As such, it seems necessary to judiciously evaluate this phenomenon and explore its outcomes as affecting the quality of instruction in higher levels of language learning.
Therefore, it seems logical to state that there is a gap between what language teaching practitioners presume their learners are gaining in the higher levels of language learning and the actual competency they show to have gained. Their gained competency is less likely to correspond with the objectives of that level especially when learners pass the intermediate level. In this regard, Lewis (1993) states that students at the intermediate level can cope in most situations, but they tend to avoid or talk around the more challenging tasks of advanced language learning.
Therefore, this study attempted to shed light on the problem that many language teachers face when teaching upper intermediate levels. It is frustrating for both language learners and teachers when they feel that their efforts do not turn to be fruitful in terms of moving learners' proficiency level forward. There are few studies regarding this phenomenon in language learning and the lack of studies in this field has left a lot of questions unanswered. The findings of this study could illuminate why and how learners hit this plateau and what they should do to overcome it.
Moreover, the literature reveals that few studies have focused on plateau phenomenon from learners' perspectives. In fact, little research has attempted to describe the process by which plateau phenomenon occurs and to also discover the common experiences that upper intermediate EFL learners have while participating in EFL classes. Exploring the experiences of upper intermediate EFL learners and developing a theory that explains these common experiences is a needed addition to the literature.
Therefore, the primary purpose of this grounded-theory study was to explore the process by which plateau phenomenon occurs in an Iranian EFL setting and to also develop a theory on plateau phenomenon. In so doing, the researchers attempted to determine the important factors contributing to plateau phenomenon from upper intermediate level EFL learners' perspective. In this grounded-theory study, the following question was addressed:
How do EFL learners describe their perceptions about plateau phenomenon?
Thirty one language learners at the upper intermediate level of language proficiency took part in the study who were selected randomly from the two different language institutes in which they were studying. The age of participants ranged from 14 to 24. Moreover, 10 language teachers, who were teaching upper intermediate levels in those institutes, were surveyed to find out about their views and attitudes on the subject.
2.2.1 Qualitative Interviews
In order to address the question of how EFL learners describe their perceptions about plateau phenomenon, some qualitative information on the views of English language learners toward the learning curve they experience during their language studies was needed. The primary instrument utilized in this study was a semi structured interview, which is the primary method of data collection in grounded theory (Ary, Jacobs, Razavieh, & Sorenson, 2006). Through the qualitative interviews, the researcher tried to elicit learners' ideas toward plateau phenomenon.
It should be noted that the plateau phenomenon is seen as a process. Therefore, the definition of process was drawn on: "a series of actions that produce something or that lead to a particular result" (Online Merriam Webster's Dictionary). It is clear that actions encompass a well-defined start and end point. This conceptualization of plateau phenomenon was used to guide the interview questions. Below are the designed questions for the interviews (before conducting the interviews, the concept of plateau was fully explained to the interviewees in order to get the most accurate data):
2.2.2 Teacher surveys
In addition to the interviews, the secondary source of data was teacher surveys. Teacher surveys are not included in the analysis involved in generating the grounded theory. Survey data was coded separately from interview data and provided a means to validate the information from the EFL learners. A brief survey was distributed among teachers from whom the participating EFL learners have received instruction. In fact, surveys were given to teachers who had observed these learners learning EFL in the intended institutes and were well familiar with them.
Surveys were open-ended and asked respondents to a) describe a specific time when they have observed their EFL students experiencing plateau, b) describe the way(s) that they think plateau can occur, and c) list the problems encountered by their EFL students experiencing plateau. It should be mentioned that both interviews and surveys were conducted in Persian language.
In order to reach the goal of this study, certain procedures were conducted. The data needed for this study was collected in three distinct phases:
Phase 1: Through interviews, the views of upper intermediate learners about plateau phenomenon were studied.
Phase 2: In addition, teacher surveys were conducted to find out about teachers' perspectives about plateau phenomenon.
Phase 3: Finally, the researcher transcribed and then codified the views of learners about the plateau phenomenon through three types of codification, namely open coding, axial coding and selective coding (Strauss & Corbin, 1998). The outcome is a theory which depicts the interrelationship among all major factors affecting language learning plateau.
The process of collecting the data was as follows: Firstly, a verbal consent to conduct the study was obtained from the accessible language institutes. From among the upper intermediate language learners, those who expressed willingness participated in the interviews. The first author conducted the interviews. Having been recorded, they were transcribed sentence by sentence. In addition, the interviews were translated into English in order to be analyzed. The length of each interview session varied between five to ten minutes depending on the willingness of interviewees to answer the questions or their degree of self-awareness and knowledge on the subject. The total number of interview sessions was five in which all the interviews were conducted.
The final technique of analyzing interview data is saturating. As the researcher develops a grounded theory, he repeatedly returns to the data to ensure that it has been fully saturated in the search for categories and their properties. By using the above techniques, it also helps to saturate the data. That is, in the process of analyzing the interview data, the researcher keeps applying the various techniques again and again in relation to categorizing, contrasting the concepts, finding out similar concepts, discovering the linkage, and doing sentence by sentence analysis.
Credibility of the findings was established through: (1) constant comparison (the provisional concepts and categories were constantly compared with transcripts in order to ensure consistency); (2) teacher surveys in which the teachers expressed their views related to their experiences with their own learners' learning plateau, and (3) member checking (provisional categories as well as the final conceptualization were shown to the participants and modifications were made for the best fit).
3. Data Analysis
In the data analysis, Strauss and Corbin's (1998) model was drawn upon which includes three types of coding procedures: (i) open coding, in which the concepts are identified; (ii) axial coding in which the main categories are presented; and (iii) selective coding in which the core category is arrived at. Based on this model, a group of similar concepts form a category, a cluster of which forms a main category, and finally, the core category emerges from connecting main categories.
3.1 Open Coding
Consistent themes from the interviewees' comments were first identified and then categorized. The total number of identified concepts from the raw data was 102. Reoccurring concepts discovered in the interviews were grouped under the same themes in such a way that they formed the initial conceptual categories. It is important to mention that the order of presentation of concepts and categories is haphazard and it is not intended to imply any priority or importance of the concepts (Appendix).
3.2 Axial coding
In this stage of coding, the categories were reexamined and the main categories along with their subcategories were developed. The main categories and their subcategories are shown in Table 1.
Curriculum and Syllabus
Going through Problems
Unpleasant Learning Experiences
After constantly reviewing the categories, three main categories which constitute the emergent theory in this study were developed. The main categories are Learner-related Variables, Instruction-related Variables, and Going through Problems. Learner-related Variables include the subcategories of Learners' Affection, Learners' Cognition, Learners' Metacognition, Learning Strategies, and Language Automatization. Instruction-related Variables comprise the subcategories of Curriculum and Syllabus, Teacher Action, Assignments and Learning Activities. Finally, Going through Problems incorporates the subcategory of Unpleasant Learning Experiences.
These three main categories summarize the whole task of codifying, grouping, and categorization of data. In other words, the axial coding of the study depicts which categories of the phenomenon under study revolve around the main axis of language learning plateau.
3.3 Selective coding
The final stage of grounded-theory study is selective coding in which the researcher reaches the core category (Strauss & Corbin, 1990). Having identified the themes and categories in open coding, and the subcategories and main categories in axial coding, a core category of the issues related to plateau phenomenon was developed in the selective coding stage. These main categories are joined together by one core category, namely Contributing Influences to Plateau. This is reflected in the form of a theory of EFL plateau (Figure 1). In fact, the theory shows the relationship among three main factors which play a role in language learning plateau and also manifests how they contribute to this phenomenon.
3.4 The Emergent Theory of EFL Plateau
Considering the emergent theory as shown in Figure 1, there are three main factors contributing to EFL plateau: Instruction-related Variables, Learner-related Variables, and Going through Problems.
Figure 1. A Theory of EFL Plateau
This theory suggests that the starting point of language learning plateau is the relevant issues related to instruction. That is, it is the type of instruction which initiates the process of language learning plateau and is to be seen as the trigger for the phenomenon. Secondly, it is the learners who are the recipient of instruction, and their characteristics can give rise to learning plateau. Thirdly, there are the problems, namely the unpleasant experiences which they undergo as a result of the type of instruction and the learner's actions, all of which eventually lead to language learning plateau. It is important to note that the arrow used in the model is intended to demonstrate the process of formation and the order in which the contributing factors cause the EFL plateau emerge. In other words, the EFL plateau (i) starts off with instructional variables, (ii) becomes reinforced by the learners' characteristics, and (iii) finally comes to surface when the learners undergo unpleasant experiences which are the signs of
reaching learning plateau.
3.4.1 Instruction-related variables
The responses that were made by participants to explain their experiences regarding language learning plateau demonstrated that some factors resulting in EFL plateau are related to instruction. One subcategory included in this main category was Curriculum and Syllabus. A strongly held belief among the participants was that the type of books and materials, their way of presenting linguistic items, and their emphasis on language skills was a factor contributing to learning plateau. For example, three of the interviewees expressed their ideas in this way:
I think that in the recent terms the reading passages and grammar have become very complicated and I feel that I used to understand more of a reading passage before than now. There are sentences that I cannot get the meaning easily. I think it is because their grammar is very complex. [Mohammad]
For me listening has become a problem. In the past I used to understand 80% of listening exercises but now I don't understand more than 50% of listening. [Bahareh]
I think that books should give some new lessons. I mean a lot of subjects in the books are just repeated and old fashioned. [Samaneh]
In the same way, a teacher said:
I believe that the books must, in the first place, present materials that are of interest to students which means that they should be more attractive in subjects and appearance, and secondly, in the upper intermediate level they should include compound and complex sentences in the instruction of grammar. [Mr. Bahrami]
The other related subcategory was Teacher Action. Some of the respondents discussed issues which were related to the activities of teachers as well as certain educational situations which play a role in learning plateau. For instance, teachers can use a wide variety of teaching aids and instruments to teach English:
Only studying books is very boring. I know teachers who play famous songs inside the class for students and they study the lyrics and use them to learn listening and other things like vocabulary. [Amir]
I prefer speaking in the class rather than studying grammar. We can study grammar in the books but the only place we can talk is here. We had a teacher who gave us a lot of time having free discussion and I learned a lot from it. [Reza]
In this regard a teacher said:
Teachers must use different modes of teaching such as using movies, reading novels, listening to news, so on. English doesn't just exist in books, it is everywhere. [Mrs. Bahrami]
The third subcategory was Assignments. Some of the interviewees mentioned the type of assignments as a factor in learning plateau:
Our teachers can give us some good homework like some interesting subjects to write about. [Amir]
I think that having free discussion in the class is very constructive. One of my teachers gave a subject to us to talk about for the next session and we had some days to think about that subject and gather information about it and bring to class. It was very good assignment. [Sahar]
In the same way, a teacher said:
I usually give my students translation assignments, mostly Persian to English. It helps them to learn how to use the new grammar and structures as well as new vocabulary correctly. [Mrs. Khalaji]
The final subcategory of Instruction-related variables is Learning Activities. These activities should lead to autonomous learners, namely learners who are independent learners and also activities which place more emphasis on accuracy:
I think a good teacher should teach us the good ways of learning by ourselves and without going to class. [Mersana]
I still make a lot of mistakes while speaking or writing. I don't know when they stop. I wish I could speak without making mistakes. [Alireza]
3.4.2 Learner-related variables
Aside from instruction, some of the responses regarding participants' experiences about language learning plateau revealed that learners' variables plays an important role in the formation of EFL plateau. One of the subcategories of learner-related variables is Learners' Affection. Some of the participants believed that affective factors influence EFL plateau:
When I started learning English, I was very happy in the classroom and I loved English very much, but now I am sometimes tired of it because it has become boring for me. [Mersana]
In the past, I used to pay attention to whatever my teacher taught us, but now it isn't very important to me to learn everything he says.[Mohammad]
If I make a mistake, the teacher will fine me or other students will laugh at me. [Amir]
In line with the mentioned extracts from learners, a teacher said:
Some learners are not as interested in learning as the time they started elementary levels. They do not take learning as seriously and enthusiastically as before.
Another subcategory of learner-related variables is Learners' Cognition. This subcategory deals with issues such as fossilization and error treatment. Some of the participants highlighted the role of cognition in EFL plateau:
I repeat some grammatical mistakes again and again. [Sanaz]
I think it is better that our teacher correct my mistakes immediately so that I can learn it and stop continuing making them. [Sepanta]
In this regard a teacher said:
Errors are inseparable components of learning process. It can even be a sign of learning. As for error treatment, giving immediate feedback on errors can be a good thing, as well as asking other students to correct each other. [Mr. Paya]
The next subcategory of Learner-related Variables is Learners' Metacognition. Some of responses reflected that learners themselves were aware of the state of getting stuck at a certain level, namely EFL plateau, and they could monitor their not progressing as before:
In recent terms, I can see that my marks are decreasing and I feel that there is something wrong with my English. [Sina]
I believe that we should have plan for learning English. If we don't have a plan goal, we won't reach any destination. For example, we should know that when we finish our terms in this institute how much English we will know, how many words we know and how well we can speak. And we should devise plans to reach these goals. [Mohsen]
In line with the mentioned extracts, two teachers said:
A key feature for students to overcome plateau is to know that they are at such a stage. They should be given goals to reach at the end of each term. [Ms. Taheri]
Students should know why they are not progressing and have stayed in the same level. Teachers should be aware of the learning styles that the students have and organize materials the way which best fits the learners. [Ms. Agahi]
The fourth subcategory of Learner-related Variables is Learning Strategies. Learning strategies are techniques learners use to enhance their learning (Scarcella & Oxford, 1992). Some of teaching participants believed that choosing appropriate learning strategies could help them get out of the plateau:
A good way to improve our English is to review the previous lesson and try to memorize previous vocabulary before starting the new lesson. I sometimes use flashcards to learning vocabulary and I always repeat the new vocabulary to myself. [Ashkan]
If I could find someone from another country, I would speak English with him/her and I could improve my English. [Zahra]
In support for the significance of having a good learning strategy, two teachers said:
It is important to give students specific assignments to consolidate the materials in them. For example, we could want them to summarize a reading passage or outline the main points in a reading. [Mr. Hakimian]
I think we should encourage learners to communicate with each other inside and outside the classroom. They should learn to use their English in every situation and they should look for people to talk to them in English. [Ms. Hashemi]
The final subcategory of Learner-related Variables is Language Automatization. Some of the interviews revealed that using language automatically is the concern of some learners:
It would be very good if we could speak English fast and without mistake. After three years of coming to English institute I feel that I speak very slowly. I think it is a problem for me and my classmates. [Keyvan]
In line with the mentioned extracts from learners, a teacher said:
We should help our students to use language faster and without a lot of thinking. If they learn to memorize some words and expressions and say them quickly, they will learn that they can extend it to other words and even to sentences. [Mr. Paya]
3.4.3 Going through problems
The third contributing influence in EFL plateau is 'Going through Problems'. It is a stage at which learners start to feel that there is something wrong with their learning and they undergo some unpleasant experiences:
In the new book we are studying, I see that reading passages have become longer and more difficult to understand. Also, there is a lot of vocabulary in the new book which is very different from previous terms. [Fatemeh]
I come to English class to learn to speak English. But I think that I am not progressing in speaking the way I expect and I feel that I am wasting my time. [Amir]
I remember I could learn a lot each term I came to class but it has been for one year that I have not changed much and my English is the same as before. [Sara]
3.4.4 Core category: Contributing influences to plateau
From what was discussed before, it is clear that there is a range of factors and influences that leads to EFL plateau. Every language learner understands and experiences it from their own perspective. The important point here is to come to a conclusive understanding of the phenomenon and connect all the issues and factors related to EFL plateau in order to provide a comprehensive explanation for this phenomenon. Accordingly, the core category presented in this study is designed in this way in order to show that a nucleus is found, which, like an umbrella, connects the three main variables of this study, namely, Instruction-related Variables, Learner-related Variables, and Going through Problems.
As stated in the model, the roots of the EFL plateau can be traced to instruction. That is to say, the type of instruction is the outset of the process of plateau formation, and in order to overcome learning plateau, we should start from reforming our pedagogical structure to meet the needs of learners in upper intermediate level. The instruction that the upper intermediate learners receive should have characteristics which are different from those of intermediate and beginner so that it prevents learners from hitting the plateau. All the factors related to instruction, from selection of materials to teachers' techniques to learning activities should be in harmony with the goal of making the learning process enjoying and at the same time novel and constructive.
Secondly, it is the factors related to learners which go hand in hand with instruction to form EFL plateau. Learners, as the recipients of instruction, play an important role in giving rigor to or hindering plateau. It is the characteristics of the learners themselves which influence the learning process and can give rise to learning plateau. The learners' feelings towards learning English as well as their actions to learn it are determinant factors which pave the way to hit the plateau. Eventually, as the result of the contributing factors of instruction and the learner, the language learners undergo some unpleasant experiences which make it evident for them that they are actually placed in a state where progressing seems to be challenging and frustrating (Going through Problems).
Taking the two major influences (instruction-related and learner-related variables) into consideration, we come the understanding that how they are actually interrelated in impeding EFL plateau: in order to help learners have the plateau situation under control and get out of it, instruction should equip them with certain materials and learning activities which are specialized to meet upper intermediate learners' challenges. At the same time, the methods and approaches devised by the instruction should also take learners' characteristics into consideration. That is, instruction should be affectively stimulating and make the best use of learners' cognitive and metacognitive capabilities. It should also train learners to devise the best learning strategies which help them to make headway in upper intermediate level. Finally, another goal of instruction should be to help learners use language automatically, for instance, by emphasizing fluency over accuracy or by presenting chunks and prefabricated expressions.
In short, the core category developed in this study demonstrates that upper intermediate language learners often hit the EFL plateau which is the result of the contributing influences of Instruction-related Variables, Learner-related Variables, and Going through Problems.
In this study, it was attempted to investigate the plateau phenomenon in language learning through the principles of grounded theory using the views of upper intermediate learners of English. The researcher went through the three main stages of open coding, axial coding, and selective coding to come to A Theory of EFL Plateau which is depicted in Figure 1. According to the theory, language learning plateau occurs as a result of the contribution of three influences namely Instruction-related Variables, Learner-related Variables, and Going through Problems. Each of these influences consists of certain factors which are going to be elaborated on to see how they account for language learning plateau. Each of these factors plays a role in language learning plateau; however, the degree of their influence for each learner is different. In other words, what was revealed from the interviews showed that each student experienced learning plateau from a specific perspective. Therefore, the presented theory illustrates the various potential aspects that play a part in language learning plateau, each of which affecting every learner in a different manner.
The first series of variables which contribute to EFL plateau are Instruction-related Variables one of whose subcategories was Assignments. The findings of the study support Bembenutty (2011) and Ramdass and Zimmerman (2011) views regarding the significance of assignments in language teaching who believe that homework has beneficial effects, such as increasing students' learning immersion time and helping them consolidate their learning, get better scores in tests, become self-regulated, develop good study habits, and practically use their knowledge. One possible explanation of the relationship between the study and previous works is that giving appropriate assignments to learners in upper intermediate level can reinforce the received materials and compliment the classroom instruction and hence assists learners in this stage to overcome EFL plateau.
In addition, Curriculum and Syllabus is another subcategory of Instruction-related Variables. The findings of this research are in line with Nunan (1999) who mentioned that curriculum should be appropriate to learners' level and enjoy variation. Also, he notes that the learners should be exposed to authentic materials as much as possible in order to prevent difficulty in their learning task. In addition, Norafkan (2013) stresses the importance of exposure to authentic and computer assisted language learning-based English materials and highlights that technology can assist learners by providing e-books and other sorts of first-hand materials. Therefore, it can be explained that books and other teaching materials used in language classrooms have to be authentic and in line with the needs of learners in upper intermediate level. One of the factors which influence learning plateau is the failure of materials to be attractive and enjoy variety in the presentation of materials. Secondly, the syllabi, for the upper intermediate level, should be designed in such a way that they can establish a reasonable balance among the four major language skills and present learners with adequate and incentive materials so that they can feel the progress they are making and hence become more motivated to learn. In general, the curriculum and syllabus along with the assignments should meet the needs of learners in the upper intermediate level in a way that they results in motivation for learning and addition of linguistic knowledge for learners.
As for learning activities, which was another subcategory of Instruction-related Variables, Learner Autonomy and Emphasizing Accuracy over Fluency are two factors which are discussed here. Learner autonomy has been seen as the learners' attitudes towards assuming responsibility for learning process and taking control of the language learning process (Balcikanli, 2010). The findings of the study are in line with Smith (2008) who believes that if students are involved in decision making processes regarding their own language competence, they are likely to be more enthusiastic about learning and learning can be more meaningful and purposeful for them. It can be explained that the more the learners are able to handle the task of learning by themselves, the more successfully they can overcome the learning plateau. Moreover, it has been stated by Ellis (2004) that emphasizing fluency at the expense of accuracy has resulted in ill-structured sentences and ungrammatical structures by learners. Therefore, for learners to overcome grammar plateau, they need to focus more on grammatically correct sentences and be attentive about the accuracy and appropriateness of the linguistic structures they utilize. There have been considerable studies on the relationship between explicit grammatical instruction and how this might relate to language skills development such as writing development (Ellis, 2004).
The final subcategory of instruction-related variables is Teacher Action one of which being the appropriateness of teaching to learners' needs. The findings of this study are supported by Khansir and Pakdel (2014) who stress that identifying the needs of learners in every instructional context is vital to the success of that teaching program. A possible explanation of this is that the teacher should devise teaching methods and techniques which fulfill the needs of learners who are supposed to reach plateau and therefore, every activity should be at the service of overcoming this challenge. In addition, alternative mediums of teaching such as songs, movies, and other appealing tasks such as Mobile Social Network Sites as studied by Ketabi and Kavoshian (2017) can help learners go past the plateau. Focusing on output is another issue which assists to get out of plateau effect. When learners are required to produce output by assigning specific tasks such as role plays and translation from first language to English, their focus will change from input to output and therefore they will be pushed to use the more advanced linguistic items which they would have avoided in plateau-stuck situation.
The second series of variables which contribute to EFL plateau are Learner-related Variables. One of the factors which play a crucial role in learning plateau is Learners' Affection. This finding is in line with the study of Latif et al. (2011) who investigated the relationship among various affective variables like attitude, motivation, anxiety, and instrumental orientation on performance in EFL. Its results indicated that all of the four variables were significantly correlated with learners' performance in the English course. One possible explanation for this is that when learners are not motivated enough to continue making advancement in their learning or do not show commitment for their learning, they will hit the learning plateau.
Moreover, based on the findings of the study, among the cognitive factors which affect learning plateau, fossilization has a central role. This finding supports the views of Selinker (1972) about fossilization who believed that learners reach a point in their learning career where their immediate knowledge of language freezes and errors do not seem to be fixed easily. Furthermore, strategic presentation of corrective feedback as studied by Shabani (2017) suggests a novel method to the treatment of errors committed by learners. In the same way, the study demonstrated that in upper intermediate level, the learners reach a state in which they feel that their linguistic knowledge has frozen in a specific level and further progress seems very difficult.
In addition, another finding of this study was that Metacognitive factors affect learning plateau. Metacognition, as was explored in this study, mainly refers to the fact that learners should monitor their process of learning, know how plateau would affect their learning, and have plans to overcome it. It supports the idea of many researchers who have focused on the role of metacognitive awareness in students' learning outcome and achievement in different school subjects, and have found that learners' metacognition can directly affect the process and the outcome of their learning (Eilam & Aharon, 2003; Mokhtari & Reichard, 2002). Moreover, Farahian's (2015) attempts to develop a measurement tool to assess metacognition made a great contribution to learners' awareness in this regard. The relationship between this finding and previous studies can explain that when upper intermediate learners can monitor their learning, they will notice a stage where the plateau occurs. This awareness will certainly help them devise procedures to get out of this state.
The influence of learning strategies was another factor in Learner-related Variables. The learners who overcome the plateau effect are those who have been well-instructed about learning strategies and use those strategies effectively. In the last three decades, many researchers have studied language learning strategies and factors related to choice and use of language learning strategies (Chamot, 2005; Oxford & Nyikos, 1989; Zhang, 2008). Therefore, this study supports previous studies which highlight the significance of learning strategies in language learning by demonstrating that when learners hit the EFL plateau, they can overcome it by devising appropriate learning strategies.
The last issue related to the learner-related variables is language Automatization. Automatization in this study refers to a state in which learners are able to produce language with minimum mental and physical effort. One of the signs of learners stuck in learning plateau is that they often make erroneous speech which is characterized by effortful struggles to remember the proper words, structures, so on. This finding is in line with McLaughlin's (1987) model of restructuring and automatization in which he discusses language learning in terms of the automatization of processing skills and restructuring of knowledge. According to him, controlled processes can be automatized through practice (McLaughlin, 1987). Therefore, to get out of learning plateau, extra practicing linguistic items plays a crucial role. Moreover, teaching learners to use chunk and formulaic expressions which are prefabricated phrases can help them produce more effortless and automatic speech.
Finally, this study supports the views of Richards (2008), Xu (2009), and Yi (2007) regarding plateau phenomenon in that when language learners reach upper intermediate level, they experience a period of immovability in their learning progress. The learners feel that they do not make advancement in accordance with the requirements of the course book and the demands of their teacher. Although the load of linguistic items, including vocabulary, grammar, idioms and expressions, is constantly increasing, the learners still resort to their previous linguistic knowledge and avoid utilizing newly learned or newly presented linguistic items. In this study, a Grounded Theory of EFL Plateau is developed which discusses the different issues related to language learning plateau from the point of view of upper intermediate language learners in Iran.