0 % vs 50 %: making a RAG agent refuse to hallucinate 2026-05-31 · LLM / RAG A retrieval-augmented agent is only as trustworthy as its behaviour on questions whose answer isn't in the corpus . The failure mode is quiet: instead of saying "I don't know," the model invents a confident, well-formed, wrong answer. This post shows a single guardrail that takes that from common to never — and, crucially, measures it. Reference architecture: nim-agent-blueprint — agentic RAG on the NVIDIA NIM stack with a built-in eval harness. The ablation The agent loop is plan → retrieve → generate → validate . The interesting variable is the generation prompt's contract with the retrieved context: Configuration Out-of-corpus hallucination rate Generate freely from context ~50 % Guarded prompt (answer only from context; otherwise abstain) 0 % Same model, same retriever, same questions. The only change is a prompt that makes "I can't answer that from the provided sources" a first-class, rewarded output — plus a validate step that checks the answer is grounded in retrieved spans before returning it. On in-corpus questions, retrieval recall@3 stayed at 94–100 % , so the guardrail buys safety without costing coverage. Why "just prompt better" isn't the lesson The lesson isn't the prompt — it's that the difference between 50 % and 0 % is invisible without an eval harness . A demo that only asks in-corpus questions looks perfect in both configurations. You only see the 50 % when you deliberately ask things the corpus can't answer and score groundedness . So the blueprint ships with: retrieval hit-rate (is the answer even retrievable?), answer groundedness via LLM-as-judge (is the answer supported by what was retrieved?), latency , and OpenTelemetry traces per agent step. That's the difference between "it works on my five questions" and "here is the number a partner can hold me to." Takeaway For enterprise RAG, abstention is a feature, not a failure. Make "I don't know" a rewarded output, vali

Author here. Wrote this from the vantage point of having shipped Android apps from 2010 to 2019-20. It's a platform-war retrospective along an axis I don't see articulated cleanly very often: update friction and channel control rather than runtime capability. Short version of the argument: The native-only residue (where mobile genuinely wins on capability) is thinner than the narrative claims. UPI in India because the device is the channel. Frame-budget and AR-heavy games. Sustained background GPS. RAW camera. Delivery/on-demand, with a tell (the apps are richer than the web versions because that's where the channel control is, not because the web cannot do it). Electron is the keystone, not a defensive aside. Slack, VS Code, Postman, Bruno, Spotify desktop. If web-versus-native were the deciding axis, the entire web-shell desktop category should have failed. It did not, because the desktop channel is open and the maintainer ships on their own cadence. PWAs are the reverse proof. Apple controls three brakes on the iOS web channel: the WebKit-only rule, the buried Add to Home Screen, and the notification permission. iOS web push did not land until 16.4 in March 2023, years after Android. When the channel is suppressed, the maintainer's update advantage does not save you. The Android hobbyist economy died not from a market outcome but from a channel outcome. Cambridge Analytica 2018 was the public license for a multi-year platform-hardening cycle (target-SDK floor, scoped storage, Play Integrity, foreground-service mandates) that progressively re-priced what kind of software was even shippable. The store does not just control the install button; the channel itself keeps narrowing on the people inside it. It's Part 1 of a two-part series on delivery channels. Posting because I'd rather have the argument tested here than not. submitted by /u/lordVader1138 [link] [留言]

I used to think AI tools were just for tech , software (like you get the point )people or big companies. But I've been experimenting for the past few months like since january start of this year ,and honestly it's changed how I work. Simple things like summarizing long articles, drafting emails, or just brainstorming it saves me so much mental energy. am still learning some though am not fully there submitted by /u/Imaginary_Bake_5820 [link] [留言]

Use iPhone to open apps, Apple Shortcuts and websites on Mac Discussion | Link

My eyes have seen the PC gaming promised land, and it's a beautifully bright world without a shred of blurriness. It's warm, it looks lovely, and it's impeccably sharp. Also, it's expensive as hell. I've dipped my toe in this world by testing a pre-production version of the upcoming Asus ROG Strix Scar 18, which […]

Speaking to TechCrunch, Crunchbase’s head of research Gené Teare, said the factors holding back Black founders include “access to networks, relationships, and early introductions."

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https://youtu.be/kL1PDqzqhM4 This video has corrected information on the history of Lorem Ipsum! submitted by /u/GreatRedditorThracc [link] [留言]

Would love to have a discussion about big companies donating LLM credits to opensource projects that are critical. Would help maintainers build sustainable pipelines for critical code we all use

A smart LLM proxy that shows where you're overpaying Discussion | Link