Comprehensible input is language input in a target language that learners can understand even if they don’t grasp every word or structure.
It is crucial for language acquisition as it helps learners acquire language naturally rather than through conscious learning.
Stephen Krashen, a linguist, introduced the concept of comprehensible input in the 1970s and 1980s as part of his input hypothesis. According to Krashen, learners improve in a language when they receive input that is slightly more advanced than their current level, known as "i + 1."
This approach emphasizes the importance of exposure to language that is just above the learner's proficiency level to facilitate learning. Krashen's theory highlights the significance of comprehensible input in language acquisition, promoting a more natural and effective way of learning a new language.
What makes input comprehensible?
Input is made comprehensible essentially through previous knowledge and meta information (or context).
In speech, the meta information may be the body language of the speaker (pointing to things, displaying emotion etc.) or the situation (being at the beach vs being in a cafe etc.).
In written language it might be the topic (politics vs sport), the format of the text (news article vs interview vs ad), illustrations etc.
What does “i+1” mean exactly?
It’s unclear exactly what “1” stands for - e.g. how much more advanced (compared to learner’s current language level) should the input be.
For everyday use it’s probably sufficient to treat it as the difference between eroticism and porn - “I know when I see it.”
Connection to compelling input
Compelling input is the type of input that is interesting to the learner, so much so, that they forgot they are learning. It is key to keep the learner motivated and learning.
Self-selected learning is a good example of this.
As it had been strongly believed that students had to be motivated to study and improve, it was a surprise that they did not have to be motivated to get better. Reading caused motivation. The SSR (self-selected reading) experience changed them. Beniko Mason, interview
A metaphor from ancient Greece
Comprehensible input is somewhat similar to the idea of getting progressively stronger by carrying more and more weight each time like Milo of Croton. He was an ancient greek athlete who was said to have been strength training with the same calf who grew heavier and heavier over time.
