Synthesizing 17 empirical studies to architect the next generation of language learning systems. Moving beyond random practice to structured, adaptive, and multi-modal competence.
Insufficient time for meaningful interaction in typical classrooms. Large class sizes prevent individualized practice.
Fear of negative evaluation leads to reluctance. Foreign language anxiety hinders willingness to communicate (WTC).
Teachers cannot provide immediate, consistent, and individualized feedback to every student due to time constraints.
A rigorous scoping review following PRISMA guidelines, filtering 2,877 records down to 17 mechanism-rich empirical studies.
Geographic Focus
Six key pillars deriving the "Why" behind effective system design.
Progression from declarative (rules) to procedural (practice) to automaticity. Requires high volume practice.
Effortful retrieval stabilizes memory. Optimal Inter-Session Intervals (ISI) create difficulty that enhances long-term retention.
Learners must consciously notice the "gap" between their output and the target. Feedback makes this gap salient.
Practice should resemble target cognitive processes. Interleaved practice simulates real-world conversational flexibility.
Language is acquired by entrenching form-meaning pairings ("constructions") through repeated use.
Learning occurs in the ZPD with a "More Knowledgeable Other" (MKO). AI/Peers act as non-threatening MKOs.
The "Double-Edged Sword": Massed practice builds speed but harms flexibility. The system must transition schedule types.
Goal: Within-task fluency & Proceduralization
Goal: Transfer & Flexible Retrieval
Goal: Long-term Retention
No single AI modality is sufficient. A robust system combines three distinct layers of feedback.
"Can you improve that sentence?" Prompting self-correction before showing answers boosts metacognition.
Explicit, color-coded feedback on segmental errors (pronunciation, phonemes). Effect size g=0.69
Assessment of naturalness, coherence, and sociolinguistic appropriateness. Scaffolds anxiety reduction.
Connect context & set clear goal.
Task execution + Tri-modal feedback loop.
"What is one pattern you noticed?" (Metacognition).
Practice architecture matters more than volume. Blocked builds foundation; Interleaved ensures transfer.
Combined ASR (Pronunciation) + LLM (Discourse) + Self-Repair creates holistic competence.
AI effectiveness is dramatically higher when wrapped in frameworks like BOPPPS (Lai, 2025).
Tracking "reuse" of grammatical constructions is a better predictor of fluency than simple WPM.