Another theory of second language acquisition is Stephen Krashen's Monitor Model. Krashen's Monitor Model theory is based on insights from psychology and linguistic theory. While Schumann's acculturation model focuses on external, social and cultural factors that affect language acquisition, Krashen's theory is based on internal psychological factors and is considered an atavist theory. Atavist theories hold that humans have an innate ability to learn language. The Monitor Model consists of five interrelated hypotheses which reflect an understanding of both linguistics and of psychology.
The Acquisition-LearningHypothesis
Krashen makes an important distinction between two ways of gaining a new language. The first of these is acquisition. According to Krashen, we acquire a new language subconsciously as we receive messages we understand. For example, if we are living in a foreign country and go to the store to buy food, we may acquire new vocabulary or syntactic structures in the process of trying to understand what the shopkeeper is saying. We are not focused on the language. Rather, we are using the language for real purposes, and acquisition occurs naturally as we attempt to conduct our business.
In contrast, learning is a conscious process in which we focus on various aspects of the language itself. This process is what generally occurs in classrooms when teachers divide language up into chunks, present one chunk at a time, and provide students with feedback to indicate how well they have mastered the various aspects of language that have been taught. Learning is associated with classroom instruction and is usually tested. It is less common in the world beyond the classroom.
The Natural Order Hypothesis
Krashen's second hypothesis is that language is acquired in a natural order. Some aspects of a language are picked up earlier than others. For example, the plural s morpheme added to a word like girl to form girls develops earlier than the third person s added to walk in "He walks." Krashen points out that all learners of a particular language, such as English, seem to acquire the language in the same order no matter what their first language may be.
The natural order applies to language that is acquired, not language that is learned. In fact, students may be asked to learn aspects of language before they are ready to acquire them. The result may be good performance of the items on a test but inability to use the same items in a natural setting. In these cases, students' performance may exceed their competence. Krashen points out that if a teacher focuses on acquisition activities, rather than trying to get students to learn certain grammatical points, all students will acquire language in a natural order. The rate of acquisition will differ for different students, but the order will be the same.
The Monitor Hypothesis
The monitor hypothesis helps explain the different functions that acquisition and learning play. Acquisition results in the vocabulary, phonology, and syntax we can draw on to produce utterances in a new language. Without acquisition, we could not produce anything. Learning, on the other hand, provides us with rules we can use to monitor our output as we speak or write. The monitor is like an editor, checking what we produce. The monitor can operate when we have time, when we focus on grammatical form, and when we know the rules. The monitor is most useful in checking written output.
Monitoring is helpful if the monitor is not over- or under-used. Teachers can help students become optimal monitor users. It does help to know the rules, but it's essential to know when to apply them and when to concentrate more on the meaning of a message. Sometimes teachers hope that by correcting their students' errors, they will increase students' proficiency. Krashen believes that error correction affects learning, not acquisition. Error correction causes us to think about consciously learned rules and has limited value. Learning, according to Krashen, has no effect on basic language competence.
The Input Hypothesis
The key to Krashen's theory of language acquisition is the input hypothesis. He claims that people acquire language in only one way-when they receive oral or written messages they understand. Krashen says these messages provide comprehensible input. In order for acquisition to take place, learners must receive input that is slightly beyond their current ability level. Krashen calls this i+1 (input plus one). If the input contains no structures beyond current competence (i+0), no acquisition takes place. There is nothing new to pick up. On the other hand, if the input is too far beyond a person's current competence (i+10), it becomes incomprehensible noise, and again no acquisition can take place.
According to Krashen, comprehensible input is the source of all acquired language. Students do not have to produce language in order to acquire it. Only input leads to acquisition consequently output, speaking or writing, does not contribute to acquisition, although it may result in cognitive development. Since comprehensible input is the key to language acquisition in Krashen's model, the teacher's job, quite simply, is to find ways to make academic content comprehensible.. This model has been implemented in several language methods used for teaching a second language, which are designed to help teachers develop techniques for turning academic content matter into comprehensible input.
The Affective Filter Hypothesis
In Krashen's work, the affective filter hypothesis explains the role of affective factors in the process of language acquisition. Even if a teacher provides comprehensible input, acquisition may not take place. Affective factors such as anxiety or boredom may serve as a filter that blocks input. When the filter is up, input can't reach those parts of the brain where acquisition occurs. Those parts of the brain are sometimes referred to as the Language Acquisition Device, or LAD. Many language learners realize that the reason they have trouble is because they are nervous or embarrassed and simply can't concentrate. In other words, the input is filtered out.
Since Krashen's theory of language acquisition is based on input, in his discussion of the affective filter he only refers to language that is coming in, not to language the person is attempting to produce. This hypothesis does not apply to a person's output, only to the ability to acquire language.
Krashen's insistence on the importance of providing learners with comprehensible input in a risk-free environment sends an important message to teachers. Krashen claims that a classroom can be an optimal source of comprehensible input. In fact, the classroom may provide more comprehensible input than a trip to a foreign country where no attempt is made to ensure that input is comprehensible.
Even though Krashen's ideas have been debated and sometimes discounted by other researchers, they have been found useful by practitioners because they are understandable and cogent. In short, they make sense. The Monitor Model has had a great impact on classroom practice and teachers see positive results when they apply techniques, based on this model, in the classroom. One drawback of the monitor model is that it fails to place a stronger emphasis on social and cultural factors; its main focus is placed on the psychological and cognitive processes that individuals go through in the SLA process, and the role teachers have in facilitating such processes.
Literature:
Ellis, R. (1990): Instructed second language acquisition. Oxford: Blackwell.
Krashen, S. (1982): Principles and practice in second language acquisition. New York: Pergamon Press.
Krashen, S. (2003): Explorations in language acquisition and use. Portsmouth: Heinemann.
