Reasoning About Uncertainty using Markov Chains

Formal methods to tackle “Trial-and-Error” problems

Nikolaus Correll
Towards Data Science
10 min readFeb 26, 2024

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The ability to deal with unseen objects in a zero-shot manner makes machine learning models very attractive for applications in robotics, allowing robots to enter previously unseen environments and manipulating unknown objects therein.

While their accuracy in doing so is incredible compared with was conceivable just a few years ago, uncertainty is not only here to stay, but also requires a different treatment than customary in machine learning when used in decision making.

This article describes recent results on dealing with what we call “trial-and-error” tasks and explain how optimal decisions can be derived by modeling the system as a continuous-time Markov chain, aka Markov Jump Process.

Perception Uncertainty

Left: Performance of the “CLIP” model on accurately providing labels for images, dramatically outperforming previous work. Image from https://arxiv.org/pdf/2103.00020.pdf. Right: Summarizing a model’s performance by a single number is only one piece of information. Once this information is actually used to make a decision, we will also need to understand the different ways the model can fail. Image: own work.

The image above shows the average performance for zero-shot image labeling from CLIP, a groundbreaking model from OpenAI that forms the basis for large multi-modal models such as LLava and GPTv4. Let’s assume, it is able to label an image containing a chicken with 70% accuracy. While this is incredible performance, in 30% of the cases, the label will be wrong.

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Nikolaus is a Professor of Computer Science and Robotics at the University of Colorado Boulder, robotics entrepreneur, and consultant.