The Krashen Revolution

By Peter McKenzie-Brown

About 25 years ago, a psychologist named Stephen Krashen transformed language teaching. He had been developing his ideas over a number of years, but several books he published in the 1980s received widespread acceptance. They quickly became the most widely accepted way to explain the twin processes of language teaching and learning. Also, with Tracey Terrell, he developed the natural approach to language teaching. One of his books is available on the web.

Much has been made of Krashen's theory of second language acquisition, which consists of five main hypotheses: The acquisition-learning hypothesis, the monitor hypothesis, the natural order hypothesis, the input hypothesis, and the affective filter hypothesis. Before we turn to these ideas, though, it is worth noting that by no means do they pertain exclusively to second language acquisition. As you read the following explanation of Krashen's five hypotheses, ask yourself whether his ideas are not equally applicable to an individual who has only one language. It seems to me that Krashen's ideas work equally well to describe how an adult native-speaker would improve her English, say, as they do to describe the process for the second language learner.

The Natural Order Hypothesis. Based on a powerful analysis of research results, Krashen’s natural order hypothesis suggests that the acquisition of language, especially the rules of language, follows a predictable natural order. For any given language, some grammatical structures tend to be acquired earlier than others. This idea reflects Noam Chomsky’s revolutionary notion that we all have a built-in Language Acquisition Device (LAD), which within the first year of our lives begins to enable us to understand and acquire language.

Because of the nature of the LAD, we tend to learn different structures at different levels as young children. Researchers have found that the same pattern occurs for older learners – not a surprise to seasoned language teachers! This is the “predictable natural order” of this hypothesis.

The Acquisition/Learning Hypothesis. The distinction between acquisition and learning is the most fundamental of all the hypotheses in Krashen's theory, since it suggests that language comes to us in two rather different ways. Acquisition is one. You acquire language by using it for real communication. Learning, which he describes as “knowing about” language, is quite a different thing.

Acquisition is the product of a subconscious process very similar to the process children undergo when they acquire their first language. It requires meaningful interaction in the target language - natural communication - in which speakers concentrate not on the form of their utterances, but in the communicative act. Learning, on the other hand, provides conscious knowledge “about” the target language. It is therefore less important than acquisition for basic communication, but it still plays an important role in language learning. To oversimplify a bit, learning is likely to occur in the “study” segment of an English lesson, while acquisition takes places during language activation.

The Monitor Hypothesis. The fundamental distinction between acquisition and learning leads directly to the next hypothesis. The monitor hypothesis relegates language learning (that is, a student’s responses to what the teacher teaches) to a secondary place in the scheme of language learning.

The monitor hypothesis is the idea that conscious learning – that is, the outcome of grammar instruction and other activities that were the traditional stock in trade of the language teacher – serve only as a monitor or an editor for the language student. Real acquisition takes place as “meaningful interaction in the target language – natural communication – in which speakers are concerned not with the form of their utterances but with the messages they are conveying and understanding.”

The Input Hypothesis. The input hypothesis suggests that people acquire language in only one way: by understanding messages, or by receiving ‘comprehensible input’. According to the input hypothesis, learner’s progress by receiving second language input that is one step beyond their current stage of linguistic competence. Acquisition for learners with language knowledge “i” can only take place if they are exposed to comprehensible input at a slightly higher level, which Krashen describes as level “i + 1”.

The Affective Filter Hypothesis. Finally, the Affective Filter Hypothesis proposes that a mental block caused by affective or emotional factors can prevent input from reaching the student’s language acquisition device. The affective filter hypothesis says that affective variables like self-confidence and anxiety play a role in language acquisition. When the filter is up – that is, when negative emotional factors are in play – language acquisition suffers. When the filter is down, it benefits.

Taken together, these hypotheses offer a practical, elegant and appealing theory of language acquisition and learning.

Putting Krashen’s Ideas to Use.
Tracy Terrell worked with Krashen to create the nuts-and-bolts practical applications of the natural approach. He borrowed widely from many methods, adapting them to meet the requirements of natural approach theory. “What characterizes the Natural Approach is the use of familiar techniques within the framework of a method that focuses on providing comprehensible input and a classroom environment that uses comprehension of input, minimizes learner anxiety, and maximizes learner self-confidence.”

He held students to a high level of accountability. They must be clear about their goals, take active roles in ensuring that input is comprehensible, make decisions about when to start producing speech, and even contribute to choices about the amount of time to be spent on grammar, for example. The teacher is a central figure in the natural approach classroom, however – the primary source of comprehensible input, and responsible for creating a friendly and encouraging class atmosphere. Also, of course, the teacher must find and introduce a rich mix of classroom activities to make the approach work.

The focus is always on introducing a little more English usage to what the students already have – i + 1, in Krashen’s formulation, – and to do so in a warm and receptive classroom. The method makes wide use of realia, props and visuals (typically magazine pictures) to introduce new vocabulary and practice comprehensible input.