By taking neural networks back to the school bench and teaching them some elements of geometry and topology we can build algorithms that can reason about the shape of data. Surprisingly these methods can be useful not only for computer vision – to model input data such as images or point clouds through global, robust properties – but in a wide range of applications, such as evaluating and improving the learning of embeddings, or the distribution of samples originating from generative models. This is the promise of the emerging field of Topological Data Analysis (TDA) which we will introduce and review recent works at its intersection with machine learning. TDA can be seen as being part of the increasingly popular movement of Geometric Deep Learning which encourages us to go beyond seeing data only as vectors in Euclidean spaces and instead consider machine learning algorithms that encode other geometric priors. In the past couple of years TDA has started to take a step out of the academic bubble, to a large extent thanks to powerful Python libraries written as extensions to scikit-learn or PyTorch.

Deepminds JAX ecosystem provides deep learning practitioners with an appealing alternative to TensorFlow and PyTorch. Among its strengths are great functionalities such as native TPU support, as well as easy vectorization and parallelization. Nevertheless, making your first steps in JAX can feel complicated given some of its idiosyncrasies. This talk helps new users getting started in this promising ecosystem by sharing practical tips and best practises.

Large generative models rely upon massive data sets that are collected automatically. For example, GPT-3 was trained with data from “Common Crawl” and “Web Text”, among other sources. As the saying goes — bigger isn’t always better. While powerful, these data sets (and the models that they create) often come at a cost, bringing their “internet-scale biases” along with their “internet-trained models.” While powerful, these models beg the question — is unsupervised learning the best future for machine learning?

ML researchers have developed new model-tuning techniques to address the known biases within existing models and improve their performance (as measured by response preference, truthfulness, toxicity, and result generalization). All of this at a fraction of the initial training cost. In this talk, we will explore these techniques, known as Reinforcement Learning from Human Feedback (RLHF), and how open-source machine learning tools like PyTorch and Label Studio can be used to tune off-the-shelf models using direct human feedback.

When building PyTorch models for custom applications from scratch there's usually one problem: The model does not learn anything. In a complex project, it can be tricky to identify the cause: Is it the data? A bug in the model? Choosing the wrong loss function at 3 am after an 8-hour coding session?

In this talk, we will build a toolbox to find the culprits in a structured manner. We will focus on simple ways to ensure a training loop is correct, generate synthetic training data to determine whether we have a model bug or problematic real-world data, and leverage pytest to safely refactor PyTorch models.

After this talk, visitors will be well equipped to take the right steps when a model is not learning, quickly identify the underlying reasons, and prevent bugs in the future.