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Next-Concept Modeling: Fast, Parallel Coarse-to-Fine Text Generation

arXiv:2610.14162CLAILG9 oct 20261 min readHN ×6PDF

Generate text from a rough sketch to fine detail, filling each level in parallel.

21×

faster

Wall-clock speedup on LM1B

Better generative perplexity than the strongest diffusion model, DUO

How it works

  1. Diffusion is still slow

    Diffusion language models need many denoising passes over the full sequence and lose quality when steps are cut.

  2. Coarse-to-fine code levels

    A VQ-VAE compresses text into levels of codes, short to long. A transformer predicts each whole level in one pass.

  3. Fewer, cheaper steps

    About 100M-parameter models match or beat diffusion baselines 10–31× faster. They also lead on Sudoku with 12 steps.

encoderesidual levelstrain onlevel by levelargmaxInput textMultiscaleVQ-VAECoarse-to-finecodesNext-ConceptTransformerDecoderto tokensGeneratedtextencoderesidual levelstrain onlevel by levelargmaxInput textMultiscaleVQ-VAECoarse-to-finecodesNext-ConceptTransformerDecoderto tokensGeneratedtext
From the paper