On a language teachers’ group, a comment was recently posted to the effect that maybe language didn’t have to be 100% comprehensible, because a young native speaker could go for a long time before asking what a key word meant. Maybe, the poster offered, comprehension could be delayed and still be comprehension?
There’s a very important difference in the conversation with a 10-year-old native speaker and the way students learn L2 in the classroom, though. In the example that was cited, the family was having a discussion about medical issues, and the son waited a good long time before finally asking “What’s a virus?” He was able to extend the ambiguity of not knowing the meaning of that key word. But are learners in the L2 classroom comparable?
In the classroom, we are working with learners who do not have the structure of the language in their heads. Our main goal (really) is to get that structure into their heads. They’ll also acquire some vocabulary along the way, because we have to “dress” the bones of the structure in those words, but still, our main focus is to give them “native speaker-ness”, which means automatically controlling all the structure of the language. No two native speakers of a language know the same set of vocabulary, but they DO have the same structural rules in their heads. (And no one ever taught them those rules. Cool, huh? 😉 )
So in the son’s case, he is actually a native speaker of that language, which means he has already internalized all its structure (certainly true by age 10!). Like a well-taught TPRS student at the end of the language’s structure, he has all the structure, but lacks breadth of vocabulary. This is where extensive reading and extensive listening serve in the same way for both learners and native speakers, though at different ages. They are starting on the foundation of having unconscious control of ALL the structure. The native speaker will have more words by the time he has all the structure, because of the environmental advantages he will have enjoyed (like far more hours of input!) But the two are comparable, really. This is the stage I call “initial fluency”: true ease of comprehension and output, but limitations in vocabulary.
For the young native speaker, learning new words or dealing with unknown items is very different than it is for a student who doesn’t have all the structure internalized. He can still get the main idea or keep up with basically what’s going on in the conversation, all while playing around in his mind “what is a ‘virus’?” (because he was thinking that, consciously or unconsciously, for a while before he asked).
Lower-level students in language classes cannot tolerate so much ambiguity. They need to have MEANING = MEANING so that they can match those up and add one more example to the stockpile of language in their heads that fits a certain pattern, so that one day, when they’ve heard enough language that has similar meaning, bang! They have acquired the structure in question.
If they cannot match MEANING to MEANING, the process is considerably slowed or even derailed. That is why comprehension is so crucial to the acquisition process, and why anything less than 100% comprehension is not the best input we can provide for our students in the very, very limited number of input hours we enjoy with them.
IMO this applies to any student who has not yet acquired all the structure of the language, though as you can imagine an advanced student will have a much higher tolerance for unknown items if the structure they occur within happens to already have been acquired. That just stands to reason — the brain can easily and unconsciously extract meaning from those known structures, and only gets “stuck” on that unknown word. But if we’re talking about unknown structures plus unknown words, things get dicier. If you give a 4th year student an unknown word in a paragraph that’s all in present tense, it will not cause nearly as much problem for them as if you gave that same student an unknown word in a paragraph that was full of past subjunctive in Spanish. The percentage of ambiguity is lower, because the present tense structure can be automatically dealt with, while the past subjunctive cannot because they are still working on that.)
So for supercharging acquisition in the classroom, I still believe that EVERYTHING must be comprehensible during input for best results. That is not to say we don’t allow some guessing and contextual clues and so on — when they have some basis for it. And we’d do that judiciously, in that present-tense paragraph, not in the middle of the past subjunctive paragraph on the second day we’ve been focusing on past subjunctive meanings.
Again, I am talking about acquisition and how to instruct lower-level students (any student who has not yet totally internalized the structure of the language) in the most efficient possible manner. As they progress, we will naturally want to shift our focus from 100% CI (by which I mean completely comprehensible CI) and 0% vocabulary expansion through independent reading and listening (which will involve guessing and the use of context — no point asking them to use context before they HAVE context in their heads!) to more and more emphasis on word study and vocabulary expansion and less time spent giving CI that will build structure.
Our ultimate goal is to not have to do TPRS anymore at all, since students will know all the structure. But to get there — to get that structure into their heads as efficiently as possible — the best CI that can be provided is 100% comprehensible CI.