TL;DR: The Architecture Overview
- • PDF parsing handles messy slide layouts, math formulas, and multi-column formats.
- • Topic segmentation groups concepts according to cognitive load theory (Sweller, 1988).
- • Retrieval-Augmented Generation (Lewis et al., 2020) strictly bounds AI outputs to uploaded texts, preventing hallucinations.
- • Multimodal synthesis couples text highlights with speech synthesis to leverage Allan Paivio's Dual Coding Theory.
1. Document Extraction & Structural Analysis
PDFs are formatted for printers, not machine understanding. When a student uploads a 60-slide PowerPoint or scanned PDF, Learnex runs an optical and semantic layout analyzer. It separates headings, equations, figure captions, and body text while filtering out header/footer noise and page numbers.
2. Topic Segmentation and Cognitive Load Chunking
Reading a 100-page document causes severe cognitive overload. In accordance with Cognitive Load Theory (Sweller, 1988), Learnex segments materials into coherent knowledge nodes called "Topics". Each topic covers one digestible conceptual unit, such as "Glycolysis Phase 1" or "Dijkstra's Algorithm Invariants".
3. Grounded Generation via RAG
The single greatest hazard of applying general LLMs to education is hallucination. When an AI invents a false formula or incorrect historical date, a student can fail an exam. Learnex employs Retrieval-Augmented Generation (RAG) (Lewis et al., 2020). Quiz questions, flashcard answers, and explanations are constrained by strict prompt boundaries: if a claim cannot be verified in the student's uploaded source text, it is omitted.
4. Audio & Multimodal Video Synthesis
Under Allan Paivio's Dual Coding Theory (1971), learning is significantly accelerated when auditory and visual sensory channels are activated concurrently. Learnex generates concise, engaging audio scripts voiced with high-clarity neural speech models, paired with synced slide highlights and interactive checkpoints.
To experience this pipeline in action, try uploading your syllabus or slide deck to our PDF to Notes generator or explore our public Learnex Labs.