Next-Concept Modeling (NCM) Explained: Will Faster AI Text Make Your Business Chatbot Better?
Stanford researchers say Next-Concept Modeling writes text 10 to 31 times faster than diffusion language models by drafting the gist first. Here is what NCM actually is, what the numbers compare against, and why no business should wait for it before fixing slow lead replies.
Next-Concept Modeling (NCM) is a research method from Stanford's Hazy Research lab that drafts the outline of a text first and fills in detail level by level. Its 10-31x speed claim is measured against diffusion language models on small research models, not against the chatbots businesses use today. A slow lead reply is a build problem you can fix now.
- NCM was published on 12 October 2026 (arXiv 2610.14162), with code on GitHub.
- Reported speedups: 21x on LM1B, about 10x on OpenWebText and 31x on XSum summarisation.
- The tested models ranged from 97M to 725M parameters, far smaller than production chat models.
- Most chatbot delay comes from lookups, tool calls and hand-offs, not only from writing the words.
- Ask vendors for measured reply times on your real channel, not model benchmarks.
Summary written with AI from this post.
Short answer: Next-Concept Modeling (NCM) is a new way for an AI model to write text: instead of producing one word after another, it first drafts a coarse outline of the whole passage and then fills in finer detail in a few parallel steps. Researchers at Stanford’s Hazy Research lab report it generates text 10 to 31 times faster than strong diffusion language models at similar quality. It is promising research, not a product you can switch on, and it is no reason to delay fixing a chatbot that answers your leads slowly today.
What is Next-Concept Modeling (NCM)?
Next-Concept Modeling is a two-stage, coarse-to-fine text generation framework. A tokenizer first learns to represent text as a hierarchy of discrete codes, from a rough “gist” level down to fine detail; a transformer then generates one level at a time, predicting every code within a level in parallel (Hazy Research). The paper, “Next-Concept Modeling: Fast, Parallel Coarse-to-Fine Text Generation” (arXiv 2610.14162), was published on 12 October 2026 by Hermann Kumbong, Ishan S. Khare and colleagues including Simran Arora, Azalia Mirhoseini and Christopher Ré, with Together AI involved in the work (AI Weekly).
A useful way to picture it: a person writing a reply usually knows the point they want to make before they choose the words. NCM tries to give a model that same order of work.
How is NCM different from how ChatGPT-style models write?
The chat models most businesses use today are autoregressive, which means they write one token (roughly a word piece) at a time, each one depending on everything before it, so a long answer takes many sequential steps. Diffusion language models, a newer research family, instead start from noise and refine the whole passage over many denoising rounds. NCM sits between the two: it commits to the big picture first and needs only a handful of parallel steps to reach the final text (Hazy Research).
How much faster is NCM, really?
Faster than diffusion language models, on small research models, by 10 to 31 times depending on the task. The authors report about 21x faster wall-clock generation on the LM1B benchmark and about 10x on OpenWebText at comparable or better quality, and 31x faster on XSum news summarisation while matching the strongest baseline, all measured on a single H100 GPU. They also report needing 4 to 5 times fewer training tokens (Hazy Research).
Two caveats matter more than the headline. First, the comparison is against diffusion models, not against the autoregressive models running inside today’s chatbots. Second, the scaling runs used models of 97M, 317M and 725M parameters, which is small next to commercial chat models, and the authors themselves note that their main quality metric “does not fully capture generative quality”.
| Benchmark | Task | Reported speedup vs diffusion LMs |
|---|---|---|
| LM1B | Open-ended sentences | About 21x |
| OpenWebText | Open-ended web text | About 10x |
| XSum | News summarisation | 31x |
Can I use NCM in my business chatbot today?
No. NCM is released as research: a paper and code on GitHub, with no hosted service from a major AI provider that a business could plug into a WhatsApp or website chatbot (Hazy Research). Good research ideas do reach products, but the path from a 725M-parameter experiment to a reliable, multilingual, tool-using production model is long and nobody has published a date for it.
Why does generation speed matter for a lead-reply bot?
Because the lead who gets a useful answer first is the one most likely to keep talking, and every second of silence is a chance for them to message a competitor. But generation is only one part of a reply’s delay. A typical lead-reply agent also looks the person up in your CRM, checks stock, prices or calendar slots, decides whether to hand off to a human, and then waits on the messaging platform to deliver the message. In our experience building these agents, the lookups and hand-offs are often where slow replies come from, and those are fixed by engineering, not by a new model architecture.
Should I wait for NCM before building an AI agent?
No, and the same answer applies to every promising research result you read about. Today’s production models are already fast enough to answer a customer in seconds when the system around them is built well. If a faster generation method becomes a real product later, a well-built agent can swap the model underneath without changing your workflows, which is exactly why we design for portability, as we explain in our post on AI model continuity. Waiting costs you the leads you are losing in the meantime.
What should I ask a vendor about speed instead?
Ask for measured reply times on your actual channel, not model benchmarks. A vendor quoting tokens per second is answering a question you did not ask; what matters is how long a real customer waits on WhatsApp or your website for a correct, useful answer, including the CRM lookup and the booking step.
- What is the typical time from a customer’s message to the agent’s reply on WhatsApp, measured on real conversations?
- What happens when a lookup or booking tool is slow: does the agent say something useful or go silent?
- Can the model be swapped later without rebuilding the agent?
- When does a human take over, and how quickly do they see the conversation?
If your leads are waiting today, that is the problem to solve first. See how we approach it on our chat agents page, or book a free 15-minute call and we will look at where your replies actually slow down.
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About Kaps
Founder & AI Lead at ClosedChats AI. Builds production AI agents and workflow automations for SMBs. Background in AI/ML systems and operations engineering.