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NewsMaterial3 min readDisconfirmAI Editorial

spaCy Author Honnibal Critiques MIT Astra Study: Conflating 'Reading Weights' with 'Modifying Weights' is Misleading

Matthew Honnibal, co-founder of Explosion and author of spaCy, published an article arguing that the recently viral MIT Astra study is seriously misleading. While the study claims the model can understand and modify other models just by observing raw weights, Honnibal's analysis reveals that the experiments involving large language models like Qwen actually rely on Python code execution and multiple forward passes, which are fundamentally different from the 'pure weight reading' conditions used for small models. He acknowledges the progress in AI's ability to act as an 'engineer' but criticizes packaging these distinct technical paths as a single 'superpower,' noting it fuels industry hype.

2026-11-05 15:10 GMT+8

Recently, a study by MIT researchers regarding the Astra model caused a sensation in the AI community. The research claimed that Astra could identify tasks performed by small neural networks simply by observing raw weight numbers, and even modify the weights of the Qwen3.5-0.8B model without using gradients, boosting its math score from 7.9% to 48.1%. Many netizens interpreted this as 'AI starting to read another AI's brain,' implying a unified, deep capability for model comprehension.

However, Matthew Honnibal, author of spaCy and co-founder of AI company Explosion, publicly questioned the presentation of this research. He argued that the study's experimental design resembles a stage magic 'misdirection': magicians may use different techniques to perform the same trick, but audiences often assume there is only one mysterious method. Honnibal pointed out that 'reading weights' and 'modifying weights' in the Astra study are actually two completely different technical paths, and bundling them together easily leads to reader misunderstanding.

After carefully reviewing eight sets of experiments in the paper, Honnibal found that the experiments strictly adhering to the condition of 'observing raw weights only' were limited to networks with very small parameter sizes (between 17K and 172K). In these experiments, Astra indeed did not run Python code or execute the target network, but instead placed the weight floating-point numbers directly into the context for analysis. While this demonstrates impressive pattern recognition, it remains far from truly understanding modern large language models.

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In contrast, the most attention-grabbing experiment—fixing Qwen's math capabilities—was conducted entirely differently. When handling the 800-million-parameter Qwen model, Astra did not directly read the raw weights. Instead, it was authorized to use Python programming and allowed up to 50 forward passes. Each pass involved processing batches of practice problems, analyzing and modifying weights based on observed performance. Honnibal emphasized that this looks more like an 'off-field coach' performing engineering debugging by writing code, running programs, and observing feedback, rather than a mystical 'brain-reading' technique.

Despite pointing out the misleading presentation, Honnibal did not dismiss the value of the research itself. He admitted that prompting an AI model to design and execute tasks typically done by human ML engineers—writing code snippets to analyze or even directly modify network weights—is a huge step forward. AI models from a year or two ago would have failed at all these tasks. This indicates that today's top-tier large models possess complex tool-use and reasoning capabilities, allowing them to diagnose and fix other models as 'AI engineers.'

The real issue lies in how the results were packaged. Blurring two distinct capabilities into a single 'superpower' capable of reading and writing AI brains not only exaggerates the actual boundaries of current technology but also reflects the widespread hype in the AI industry. For readers, distinguishing between 'pattern recognition based on raw data' and 'engineering intervention based on code execution' is crucial for accurately assessing the real progress of AI in model interpretability and automated engineering.

Sources

  • qbitai.com量子位↗
  • honnibal.dev↗
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