Apply Comprehensible Input Strategy

---
name: apply-comprehensible-input-strategy
description: Use when a learner wants to accelerate acquisition through structured exposure to target-language content just above their current level
source: Stephen Krashen "The Input Hypothesis" (1985); Mason & Krashen "Extensive Reading in English as a Foreign Language" (1997); Free Voluntary Reading research
tags: [comprehensible-input, reading, listening, acquisition]
verified: true
---

# Apply Comprehensible Input Strategy

Select, sequence, and consume target-language content pitched at i+1 (one step above current level) so acquisition occurs naturally through meaning-focused exposure.

## Why This Is Best Practice

**Adopted by:** ACTFL extensive reading programs, University of Southern California language acquisition research, Japanese language schools using TPRS (Teaching Proficiency through Reading and Storytelling)
**Impact:** Mason & Krashen (1997) found extensive reading groups outperformed grammar instruction groups on all measures; Krashen's FVR studies show 30 minutes daily free reading yields vocabulary gains equivalent to explicit instruction with 3x the study time
**Why best:** Acquisition is subconscious and occurs through meaning-focused exposure — explicit study transfers to monitor use only; i+1 input triggers hypothesis formation and pattern internalization without metalinguistic overhead

Sources: Krashen (1985) input hypothesis and i+1 concept; Mason & Krashen (1997) extensive reading evidence; TPRS research base

## Steps

1. **Determine current level precisely** — read or listen to three candidate texts; select the level where you understand 70–80% without a dictionary.
2. **Apply the i+1 filter** — choose content where new vocabulary or structures constitute no more than 20% of each passage; beyond that, input is incomprehensible.
3. **Build a graded content ladder** — sequence materials from current level to target level in steps: graded readers (A2 → B1 → B2), then authentic texts with glosses, then unmodified native content.
4. **Prioritize volume over precision** — read and listen for quantity; 30+ minutes daily of comprehensible input outweighs 10 minutes of intensive analysis.
5. **Use context before dictionary** — attempt to infer unknown words from surrounding context; only look up words that block comprehension after two failures.
6. **Log encounters, not lookups** — mark words seen in context without looking up; after 3–5 encounters, add to SRS deck if still unknown.
7. **Select intrinsically interesting content** — motivation drives continuation; a compelling story sustains 60-minute reading sessions that textbook exercises cannot.
8. **Use narrow reading/listening** — consume multiple texts on the same topic or by the same author; repeated vocabulary and syntax patterns consolidate faster.
9. **Do not force output during input sessions** — comprehensible input sessions are acquisition-mode, not performance-mode; note-taking is acceptable, speaking is not required.
10. **Track comprehension percentage weekly** — if comprehension on new material improves, step up to harder content; plateau signals need to expand content variety.

## Rules

- 70–80% comprehension is the acquisition sweet spot — above 95% is too easy; below 60% is noise.
- Never use bilingual texts as the primary input — parallel translation prevents the brain from building direct target-language meaning associations.
- Extensive reading requires volume — fewer than 10,000 words per week yields measurable but slow gains; 50,000+ words per week produces rapid vocabulary growth.
- Input quality matters: native-speaker content at appropriate level beats simplified learner materials at higher level.

## Common Mistakes

- **Using a dictionary every other sentence** — constant interruption breaks the meaning-focus state; defer lookup until comprehension collapses.
- **Choosing content that is too advanced to impress** — reading literary C2 texts at B1 produces frustration, not acquisition.
- **Treating input as a supplement to grammar study** — at B1+, comprehensible input should be the primary acquisition engine, not a supplement.
- **Confusing quantity with quality** — passive background listening to incomprehensible audio is not comprehensible input; attention and comprehension are required.

## When NOT to Use

- Learner is at true A0 with no phonological map of the language — structured pronunciation and core phrase instruction must precede input flooding
- Exam requires explicit grammar rule production (e.g., translation exam, formal grammar test) — explicit instruction is more efficient for that specific output type
- Learner has dyslexia or reading disability — audio-primary comprehensible input strategies should substitute for reading-dominant approaches