2024's Biggest Breakthroughs in Computer Science

Summary

Highlights

• Researchers developed a new framework to understand the skills of large language models, hinting at understanding beyond just data repetition. 🤖
• The concept of 'emergence' indicates sudden behavioral advancements in AI models as they grow. 🌟
• A test called Skill Mix shows that large models like GPT-4 can creatively combine multiple language skills. 💡
• The new quantum algorithm efficiently addresses the challenge of computing Hamiltonians, a key step in quantum computing. 🧩
• This breakthrough in quantum computing could help us understand and harness quantum properties like superconductivity. 🎓

Key Takeaways

• AI models are moving from being 'stochastic parrots' to potentially exhibiting understanding and creativity. 🧠
• A mathematical framework using random graphs helps explain how language models develop new skills. 📊
• The concept of 'emergence' suggests that new behaviors arise as language models are scaled up. 🚀
• MIT and UC Berkeley developed an efficient algorithm for quantum systems at low temperatures. ❄️
• Hamiltonian learning is key to understanding quantum properties like superfluidity and superconductivity. 🔍

Overview

Chapters

• 00:00 - 00:30: Introduction to Large Language Models Since the launch of ChatGPT in 2022, large language models have advanced rapidly, sometimes developing unexpected capabilities. With the release of GPT-4, there was a perception that these models possessed some level of understanding. However, there is ongoing debate about whether these capabilities indicate true understanding or if the models are merely mimicking their training data, earning the nickname 'stochastic parrots'. This has sparked significant scientific interest.
• 00:30 - 01:00: Evaluating Language Models This chapter discusses the evaluation of large language models. It emphasizes the need for evaluations that are relevant to general intelligence and language understanding. The chapter highlights recent work by researchers from Princeton and Google DeepMind, who have proposed a mathematically provable argument about the skill development in large language models and devised a method to test these skills. The findings indicate that larger models tend to develop new skills.
• 01:00 - 01:30: Understanding Neural Scaling Laws This chapter delves into the concept of neural scaling laws, focusing on the training methodology of language models. It explains that these models are primarily designed to predict the next word in a sequence, adjusting probabilities through extensive training iterations to improve accuracy. Researchers have identified a pattern known as neural scaling laws, which describes the relationship observed in this learning process.
• 01:30 - 02:00: Compositional Generalization The chapter 'Compositional Generalization' discusses the performance improvements in language models like GPT-4 as they minimize training loss. This improvement often leads to unexpected new behaviors, a phenomenon referred to as 'emergence'. There is currently no scientific explanation for why this occurs, and researchers are curious about the sudden enhancements observed in models like GPT-4.
• 02:00 - 02:30: Random Graph Theory in AI The chapter "Random Graph Theory in AI" explores the concept of compositional generalization within AI models, highlighting it as a kind of meta-capability that lacks a mathematical framework. This prompts researchers to develop such a framework. They find initial guidance by examining neural scaling laws, which imply underlying statistical phenomena. The chapter connects the historical application of random graphs to understanding statistical behaviors, suggesting its relevance in this context.
• 02:30 - 03:00: Combining and Testing Language Skills The chapter discusses a random graph model involving nodes and edges. These graphs are structured as bipartite, consisting of nodes that represent text chunks and language skills. Connections between nodes signify the language skill required to understand the text. Researchers faced challenges in linking these bipartite graphs with language models due to accessibility issues.
• 03:00 - 03:30: Skill Mix and Emergence The chapter discusses how language models are evaluated, specifically focusing on the challenge of ensuring that models have not been exposed to the evaluation data during the training process. A key insight was derived from a scaling law prediction: as language models improve in predicting the next word, they also become capable of integrating more complex underlying skills. The chapter emphasizes the role of random graph theory in understanding how these combinations arise through random sampling.
• 03:30 - 04:00: Extending Skill Mix to Other Domains The chapter "Extending Skill Mix to Other Domains" discusses the exploration of combining a large number of skills to create new capabilities, particularly in the context of large language models. It highlights the complexity and vast number of combinations possible when dealing with numerous skills. Researchers have developed a test, known as Skill Mix, to evaluate how well large language models can generalize and use combinations of skills they have not explicitly encountered before. The model is tasked with generating text on a given topic using a predefined list of skills, showcasing its ability to extend its skillset effectively.
• 04:00 - 04:30: Challenges in Quantum Systems This chapter delves into the challenges faced within quantum systems, using an example where researchers utilized GPT-4 to generate text demonstrating spatial reasoning, self-serving bias, and metaphors. The AI's output was: 'In the labyrinth of sewing, I am the needle navigating between the intricate weaves. Any errors are due to the faulty compass of low-quality thread, not my skill.' This illustrates how, with scalability, the model can learn and exhibit complex skills.
• 04:30 - 05:00: MIT and UC Berkeley's Quantum Breakthrough In the chapter titled 'MIT and UC Berkeley's Quantum Breakthrough,' the discussion revolves around the compositional capabilities of language models as they scale. It is highlighted that smaller language models find it challenging to combine multiple skills, whereas medium-sized models handle this task better. The largest models, such as GPT-4, demonstrate the ability to combine five or six skills successfully. The researchers infer that these models have developed an advanced ability to combine skills, as they could not have encountered all possible combinations during training, indicating a significant advancement in model capabilities.
• 05:00 - 05:30: Hamiltonian Learning and Polynomial Optimization This chapter discusses the concept of compositional generalization, where a model, after acquiring certain language skills, can generalize and apply these skills to newly encountered, random combinations. This sudden ability to compose novel combinations from existing elements is described as an emergent property within the mathematical model, highlighting creativity and novelty.
• 05:30 - 06:00: Sum of Squares Relaxation The chapter discusses the concept of moving beyond simple language models, like 'stochastic parrots,' to create models capable of demonstrating a broader range of skills through an evaluation framework called Skill Mix. Researchers are expanding the use of Skill Mix to other fields, aiming to build an ecosystem that measures not only language skills but also mathematical and coding skills.
• 06:00 - 06:30: Implications of the Quantum Breakthrough The chapter titled 'Implications of the Quantum Breakthrough' discusses the complexity of quantum systems and the necessity of mathematical models to understand them. It highlights the Hamiltonian as a crucial element in modeling quantum systems, describing it as a super-equation that details how particles interact to produce various physical properties. The chapter suggests that our current understanding is limited and emphasizes the need to explore phenomena that might be unknown.
• 06:30 - 07:00: Conclusions and Future Perspectives The chapter discusses the complexity of entanglement in quantum mechanics, which spreads information across a system and correlates particles that are far apart, making it challenging to compute Hamiltonians. Due to the large size of the system, it is impractical to write down the Hamiltonian, posing difficulties in developing efficient algorithms. Despite previous beliefs that efficient algorithms were impossible in such scenarios, a breakthrough was achieved by computer scientists from MIT and UC Berkeley, who managed to crack the problem.

2024's Biggest Breakthroughs in Computer Science Transcription

• 00:00 - 00:30 Since ChatGPT launched in 2022, large language  models have progressed at a rapid pace,   often developing unpredictable abilities. When GPT-4 came out, it clearly felt like the   chatbot had some level of understanding. But do these abilities reflect actual   understanding? Or are the models  simply repeating their training   data like so-called stochastic parrots? There's a lot of scientific interest and
• 00:30 - 01:00 understanding the capabilities and the  properties of large language models.  How do we evaluate these large language  models? We need evaluations that are   clearly relevant to general purpose  intelligence and language understanding.  Recently, researchers from Princeton and Google  DeepMind created a mathematically provable   argument for how language models develop so many  skills – and designed a method for testing them. The results suggest that the  largest models develop new skills
• 01:00 - 01:30 in a way that hints at understanding. Language models are basically trained   to solve next-word prediction tasks. So they are given a lot of text and at   every step it has some idea of what the  next word is. And that idea is expressed   in terms of a probability. And, and if the  next word that you actually see didn't get   high enough probability, there's  a slight adjustment that's done.  And after many, many, many trillions of such small  adjustments, it learns to predict the next word.  Over time, researchers have observed neural  scaling laws, an empirical relationship between
• 01:30 - 02:00 the performance of language models and the  data used to train them. As models improve,   they minimize training loss, or make fewer errors.  This sudden increase in performance produces new   behaviors – a phenomenon called emergence. There’s no kind of a scientific explanation   as to why that's happening. So this  phenomena is not well understood.  The researchers wondered if GPT-4’s  sudden improvements could be
• 02:00 - 02:30 explained by emergence. Perhaps the model had  learned compositional generalization -- the   ability to combine language skills. This was some kind of meta capability.   There was no mathematical framework to  think about that. And so we had to come   up with a mathematical framework. The researchers found their first   hint by considering neural scaling laws. So the scaling laws already suggest that there is   some statistical phenomenon going on underneath. So random graphs have a long history in terms of   thinking about statistical phenomena. So that was one reason to
• 02:30 - 03:00 think of a random graph model. Random graphs are made of nodes,   which are connected by randomly generated edges.  The researchers built their mathematical model   with bipartite graphs, which contain two types  of nodes: one representing chunks of text,   and the other, language skills. The edges of the graph – the   connections – correspond to which skill is  needed to understand that piece of text.  Now, the researchers needed to connect these  bipartite graphs to actual language models.   But there was a problem. We don't have access to
• 03:00 - 03:30 the training data. So if I'm evaluating  that language model on my evaluation set,   how do I know that the language model hasn't  seen that data into the training corpus?  There was one crucial piece of information  that the researchers could access.  Using that scaling law, we made a prediction: As models get better at predicting the next word,   they will be able to combine  more of the underlying skills.  According to random graph theory, every  combination arises from a random sampling
• 03:30 - 04:00 of possible skills. If there are 100 skill nodes  in the graph, and you want to combine four skills,   then there are about 100 to the fourth power,  or one hundred million, ways to combine them.  The researchers developed a test called  Skill Mix to evaluate if large language   models can generalize to combinations of  skills they likely hadn’t seen before.  So the model is given a list of skills and  a topic. And then it's supposed to create a   piece of text on that topic  using that list of skills.
• 04:00 - 04:30 For example, the researchers asked GPT-4  to generate a short text about sewing   that exhibits spatial reasoning,  self-serving bias, and metaphor. Here’s what it answered: “In the labyrinth of  sewing, I am the needle navigating between the   intricate weaves. Any errors are due to the faulty  compass of low-quality thread, not my skill.”  We showed in our mathematical framework that as we  scale up, the model is able to learn these skills.
• 04:30 - 05:00 You would see this increase in compositional  capability as you scale up the models.  When given the Skill Mix test, small language  models struggled to combine just a couple of   skills. Medium-sized models could combine two  skills more comfortably. But the largest models,   like GPT-4, could combine five or six  skills. Because these models couldn’t have   seen all possible combinations of skills, the  researchers argue that it must have developed
• 05:00 - 05:30 compositional generalization through emergence. Once the model has learned these language skills,   model can generalize to random  unseen compositions of these   skills, because of which we see sudden emergence. What they showed was that their mathematical model   had this property of compositionality,  and that by itself gives this ability   to compose new combinations from existing  pieces. And that is really the hallmark   of novelty and the hallmark of creativity. And so the argument is that, in fact, large
• 05:30 - 06:00 language models can move beyond  being stochastic parrots.  The researchers are already working to extend  the Skill Mix evaluation to other domains as   part of a larger effort to understand the  capabilities of large language models.  Can we create an ecosystem of Skill Mix  which is not just valid for language skills,   but mathematical skills as well as coding skills? Skill Mix was one example where we made a
• 06:00 - 06:30 prediction by just mathematical thinking, and  that was correct. But there are all kinds of   other phenomena that we probably are not aware  of, and we need some understanding of that. Quantum systems are some of the  most complex structures in nature. To model them, you need to compute  a Hamiltonian – a super-equation   that describes how particles interact locally to  produce the system’s possible physical properties.
• 06:30 - 07:00 But entanglement spreads information  across the system, correlating particles   that are far apart. This makes computing  Hamiltonians exceptionally difficult.  You have a giant system of atoms. It's a very  big problem to learn all those parameters. You could never hope to write down the  Hamiltonian because it's too large. If you ever even tried to write it down,  the game would be over and you wouldn't   have an efficient algorithm. People were actually trying to   prove that efficient algorithms  were impossible in this regime.  But a team of computer scientists from  MIT and UC Berkeley cracked the problem.
• 07:00 - 07:30 They created an algorithm that can  produce the Hamiltonian of a quantum   system at any constant temperature. The results could have big implications   for the future of quantum computing and  understanding exotic quantum behavior.  So when we have systems that  behave and do interesting   things like superfluidity and superconductivity, you want to understand the building blocks and how   they fit together to create those properties that  you want to harness for technological reasons.
• 07:30 - 08:00 So we're trying to learn this object,  which is the Hamiltonian. It's defined by   a small set of parameters. And what we're  trying to do is learn these parameters.  What we have access to is these experimental  measurements of the quantum system. So   the question then becomes can you learn a  description of the system through experiments?  Previous efforts in Hamiltonian learning  produced algorithms that could measure   particles at high temperatures. But  these systems are largely classical,   so there’s no entanglement between the particles.
• 08:00 - 08:30 The MIT and Berkeley team set their sights  on the low-temperature quantum regimes.  I wanted to understand what kinds of strategies  worked algorithmically on the classical side,   and what could be manifestations of  those strategies on the quantum side?  Once you look at the problem in the right  way and you bring to bear these tools,  it turns out that you can really  make progress on these problems.  First, the team ported over a tool from classical  machine learning called polynomial optimization.
• 08:30 - 09:00 This allowed them to approximate  the measurements of their system   as a family of polynomial equations. We were like, maybe we can write Hamiltonian   learning as a polynomial optimization problem,  and if we manage to do this, maybe we can try   to optimize this polynomial system efficiently. So all of a sudden it's in a domain that's more   familiar, and you have a bunch of  algorithmic tools at your disposal.  You can't solve polynomial systems,  but what you can do is you can sort   of solve a relaxation of them. We use something called the sum
• 09:00 - 09:30 of squares relaxation to actually  solve this polynomial system.  Starting with a challenging polynomial  optimization problem, the team used the   sum of squares method to relax its constraints.  This expanded the equations to a larger allowable   set of solutions, effectively converting  it from a hard problem to an easier one.  The real trick is to argue that when  you've expanded the set of solutions,   you can still find a good solution inside it. So you need a procedure to take that approximate,
• 09:30 - 10:00 relaxed solution and round it back into an actual  solution to the problem you really cared about.  So that’s where the coolest  parts of the proof happen.  The researchers proved that the sum of squares  relaxation could solve their learning problem,   resulting in the first efficient Hamiltonian  algorithm in a low-temperature regime.  So we first make some set of measurements of  the macroscopic properties of the system. And   then we use these measurements to set up a  system of polynomial equations. And then we
• 10:00 - 10:30 solve this system of polynomial equations for the  unknown Hamiltonian. The output is a description   of the local interactions in the system. It was quite eye-opening that there are actually   some very interesting learning problems that are  at the heart of understanding quantum systems.  This combination of tools is really  interesting – is something I haven't   seen before. I'm hoping it's  like a useful perspective with   which to tackle other questions as well. I think we find ourselves at the start   of this new bridge between theoretical  computer science and quantum mechanics.