It’s all there. All the evidence that humans baaaaaaasically need to hear/view/read language (i.e., input) that they understand (i.e., comprehensible) is at this point un-questioned. N.B. While the second language acquisition (SLA) field has dropped the word “comprehensible,” now referring to “input” only, teachers are far more likely to identify these researched practices under the broad “CI” term. Bottom line, CI-based practices cannot be dismissed. They can’t really be expected to cause a stir anymore. Instead, it’s discussion involving a mix of opinion and research about “the X amount of Y beyond input” that causes a stir these days. However, let’s recognize the outcome of that discussion is not nearly as important as providing input. It’s not equal. It’s not even 3/4ths. Focusing on input gets us probably 90% there. Add some interaction and purpose for hearing/viewing/reading input, and that’s like 99%.

If only it were that simple.