👩‍🎓 PhD, 🧠 AI Researcher, 📺 ML videos creator on YouTube: https://xitter.cf/t.co/yd92HLx342 ▶ @AICoffeeBreak

Joined August 2020
Replying to @letiepi
@letiepi has a new Twitter handle: @AICoffeeBreak. Keeping the professional profile separated from the private one. Once again, I would like to express my gratitude for being on this amazing list!
My favorite ML educators: [1/n] - @JayAlammar: visual guides on NLP - @fishnets88: intuition & real-world anecdotes - @CShorten30, @ecsquendor, @ykilcher : netflix of research papers - @letiepi: bite-size animated videos on ML - @nlpguy_: experience on NLP in industry
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Letiția Pârcălăbescu retweeted
Kolibri, day 4. #1 trending text generation model on Hugging Face. 30 community builds. First GGUF went up 11 hours after release. Runs on Apple Silicon, llama.cpp, Blackwell, a single 4090. The most downloaded version isn't ours anymore. Built by @Aleph__Alpha. Now built on by everyone. That's how open weights should work.
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Letiția Pârcălăbescu retweeted
We started the year with the conviction that Europe needs its own sovereign AI. Built in Germany from scratch and on infrastructure in Europe specifically for our customers. This weekend, we released Kolibri. Meet the team behind it 🧵
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Proud to have helped build Kolibri 🐦 We brought our Merlin-Arthur work on grounding and hallucination reduction into the model. Iteration one: scale brings its challenges, but the training pipeline lets us learn and iterate fast.
Small bird, fast wings, Kolibri is here. 78B parameters. 3.46B active. Up to 1M tokens of context. Built in Europe. Now the weights are yours. Run it on your own hardware, under Apache 2.0.
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Letiția Pârcălăbescu retweeted
Kolibri is out 🐦 (Apache 2.0) and new research ideas around measuring grounding and reducing hallucinations with Merlin-Arthur made it into the model. This is just the beginning: lots of open questions, lots still to improve. But getting research ideas into an actual model, learning from them, and having an amazing in-house model training pipeline to iterate quickly is the fun part.
Small bird, fast wings, Kolibri is here. 78B parameters. 3.46B active. Up to 1M tokens of context. Built in Europe. Now the weights are yours. Run it on your own hardware, under Apache 2.0.
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Letiția Pârcălăbescu retweeted
Small bird, fast wings, Kolibri is here. 78B parameters. 3.46B active. Up to 1M tokens of context. Built in Europe. Now the weights are yours. Run it on your own hardware, under Apache 2.0.
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Letiția Pârcălăbescu retweeted
New AI Coffee Break video! 🔥☕️ LLMs can hallucinate and give the correct answer for the wrong reason. What about teaching them to admit “I don’t know”? This is what my research with colleagues at Aleph Alpha Research on Merlin-Arthur protocols is about. Here's a video to explain the complicated aspects of this work. Link below:
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Letiția Pârcălăbescu retweeted
Asking an LLM to cite its sources does not tell you whether its answer actually came from those sources. Citations can sound perfectly plausible, while the answer itself came from memorization, spurious cues no human deems relevant, or a lucky guess. So, we came up with a measure of how much of an answer actually came from the provided context in RAG & and a way to train for it. More on Merlin, Morgana & Arthur in the blog post 👇
Your model answers 9 of 10 questions correctly about a contract you gave it to check, but you don’t know which one is wrong, so you check all 10. LLM training rarely rewards "I can’t answer": abstaining pays less than guessing, so models guess plausibly, & that’s hallucination.🧵
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Letiția Pârcălăbescu retweeted
Your model answers 9 of 10 questions correctly about a contract you gave it to check, but you don’t know which one is wrong, so you check all 10. LLM training rarely rewards "I can’t answer": abstaining pays less than guessing, so models guess plausibly, & that’s hallucination.🧵
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Letiția Pârcălăbescu retweeted
LLMs can memorize even a phone number seen once in training.🔒 Google’s VaultGemma fixes that, being the first open-weight LLM trained from scratch with differential privacy, so rare secrets leave no trace. ☕ new video explaining Differential Privacy through VaultGemma 👇
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We explain diffusion models and flow-matching models side by side. Flow-Matching models are the new generation of AI image generators that are quickly replacing diffusion models. They take everything diffusion did well, but make it faster, smoother, and deterministic.
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Ever wondered how Energy-Based Models (EBMs) work and how they differ from normal neural networks? ☕️We go over EBMs and then dive into the Energy-Based Transformers paper to make LLMs that refine guesses, self-verify, and could adapt compute to problem difficulty. (link👇)
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The world’s largest NLP conference with almost 2,000 papers presented, ACL 2025 just took place in Vienna! 🎓✨Here is a quick snapshot of the event via a short interview with one of the authors whose work caught my attention. 🎥 Watch: youtu.be/GBISWggsQOA #acl2025NLP #acl2025
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Letiția Pârcălăbescu retweeted
How do LLMs pick the next word? They don’t choose words directly: they only output word probabilities. 📊 Greedy decoding, top-k, top-p, min-p are methods that turn these probabilities into actual text. In this video, we break down each method and show how the same model can sound dull, brilliant, or unhinged – just by changing how it samples.
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Excited to be at #ACL2025NLP in Vienna this week. 🇦🇹 I’m always up for a chat about reasoning models, NLE faithfulness, synthetic data generation, or the joys and challenges of explaining AI on YouTube. If you're around, let’s connect!
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Letiția Pârcălăbescu retweeted
🧠🤖 Can we trust AI in science? I'm excited to be speaking at the final event of the Young Marsilius Fellows 2025, themed "Dancing with Right & Wrong?" – a title that feels increasingly relevant in the age of AI. I'll be joining a panel on "(How) can we trust AI in science?" to discuss questions like: 🔨 What recent advancements in AI were particularly impactful for science? 🔍 How do we calibrate trust in current AI systems? 🧪 If AI takes over more of the scientific process… what’s left for us humans? 📅 Looking forward to the discussion and to learning from fellow panelists and participants. If you're around Heidelberg, join us!
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💡 AlphaEvolve is a new AI system that doesn’t just write code, it evolves it. It uses LLMs and evolutionary search to make scientific discoveries. We explain how AlphaEvolve works and the evolutionary strategies behind it (like MAP-Elites and island-based population methods).
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Say hi if you're at ICLR! 👋
The last paper of my PhD @HD_NLP is accepted at ICLR 2025!🙌 We investigate the reliance of modern Vision & Language Models (VLMs) on image🖼️ vs. text📄 inputs when generating answers vs. explanations, revealing fascinating insights into their modality use and self-consistency.👇
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Excited to share that I’ll be joining the Summer School “AI and Human Values” this September at the Marsilius-Kolleg of Heidelberg University as a speaker. I'll be giving an introduction to how large language models actually work—before the summer school dives deeper into their ethical, legal, and societal implications. 👉 marsilius-kolleg.uni-heidelb… 🧠 This interdisciplinary event brings together researchers from across fields—computer science, linguistics, philosophy, law, medicine, theology—to explore the normative foundations of generative AI, and how values are embedded in its design. 📍 Heidelberg, September 21–27, 2025 💬 Language: English 🎯 Open to PhD students & advanced Master’s students from all disciplines working on AI-related research 💡 Participation includes talks, workshops, and lots of cross-disciplinary exchange—with accommodation and meals covered (fee: 100€). If this sounds like your thing, the application deadline is June 27! #AI #InterdisciplinaryResearch #GenerativeAI #Heidelberg #SummerSchool
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Long videos are a nightmare for language models—too many tokens, slow inference. ☠️ We explain STORM ⛈️, a new architecture that improves long video LLMs using Mamba layers and token compression. Reaches better accuracy than GPT-4o on benchmarks and up to 8× more efficiency.👇
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Letiția Pârcălăbescu retweeted
It was really great talking to many people at #ICLR in Singapore about my last paper written during my PhD! 📜
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