lacoco-lab

Theoretical Abilities and Limitations of Language Models

Course Description: LLM have amazing capabilities, but also hallucinate and make reasoning mistakes. Can we understand these abilities and limitations theoretically, as way to figure out ways of overcoming them? The incredible scale of current LLMs makes this a daunting prospect. However, recent research has developed mathematical understanding sheeding light on questions such as:

Research on these questions draws on fields such as computational complexity, formal language theory, and statistical learning theory.

Prerequisites: This seminar will not presuppose knowledge of any of these fields. However, a willingness to engage with technical content is important.

We will discuss recent research papers, both from our own group and from other groups. A lot of this content is highly technical, and it is absolutely fine if you do not understand everything in the paper you’ll present. Our focus will be on discussing high-level take-aways for understanding the (in)abilities of current AI systems, and prospects for future developments.

Course Management System: CMS

Instructors: Xinting Huang and Michael Hahn

Time: Wed 10:15–11:45

Room: Building C7.3 Room 1.14

Registration:

Syllabus

TBD. A few relevant papers. We will expand this.

You are very welcome to propose readings that you are interested in, as long as they are related to the topic of the seminar! Please email us such suggestions.

The path to AGI:

Scaling laws and emergence:

Formal languages as a tool for understanding transformers’ limitations:

Theoretical results and LLM performance:

Chain of Thought:

Learning and Generalization:

SSMs as a competing architecture:

k-hop reasoning:

Evaluation

Important: Study programs may differ in which versions of the class you can take. Please check with your study program coordinator if in doubt.

For students taking the seminar for 4 credits:

Presentation: 60%
Questions about readings: 40%

For students taking the seminar for 7 credits:

Presentation: 30%
Questions about readings: 20%
Final paper: 50%

Questions

Please register on the forum on CMS.

Starting from the fourth week, every student submits one question about the readings by Tuesday noon. Questions are graded on a 3-point scale (0: no question submitted, 1: superficial question, 2: insightful question). Students can also submit a few more questions, the grade will be calculated as the highest score among questions.(So you can also ask some basic questions that you want clarification)

Presentations

We expect that presentations will cover the key points from the readings, such as the main evidence for and against the key claims under consideration in the paper.

We do not expect that presentations will cover all details of the papers. Rather, you should focus on big picture findings and conclusions, and are not expected to include every finding from the paper in your presentation. For instance, instead of a table of numbers, highlight key results. When there are multiple similar results in the paper, synthesize them. If the papers have many studies, you might select a presentative subset to explain the paper’s conclusions. On the other hand, if the assigned papers primarily discuss/review other work, draw on material from the work cited to provide richer content and even details where useful. Also, sometimes there is just one paper in a seminar session, so you will have more time and may cover more details.

Make sure to motivate the papers’ research question(s). Give background on key concepts, and convey to the audience your understanding of why certain research decisions were made.

Select what you consider the key points; you are not expected to cover every part of the paper exhaustively. Include details only to the extent that you believe them to be important.

Critically engage with the reading: contribute your own opinion on the key findings, and on the paper’s motivation and arguments. In what ways do or don’t you agree with arguments made by the authors?

As you’ll be presenting in teams of two, don’t just present the two papers separately, but make sure to also draw connections and compare. Aim for 40-60 minutes of presentation, allowing 30-40 minutes of discussion. You will have sufficient time, so avoid speaking too fast for others to keep up, make sure your audience is following. You can do so by giving more examples, or simply repeating again. Making presentation is to convey information, if audience cannot follow, it’s waste of time for both sides. Generating and moderating in-class discussion is a key component of your presentation – thinking about what will be interesting to your audience will thus be important. Discussion should happen not just after the presentation, but you should engage the audience and create ample opportunity for discussion during your presentation. Before the presentation, take a look at the questions that have been posted in the forum and refer to these as needed. These may be useful for getting discussion started. Conversely, when attending other students’ talks, reciprocate by participating actively in the discussion.

Final Papers (for the 7CP version)

Note: We will discuss this in the first meeting. Requirements may be changed based on popular demand.

Term papers will be about a small independent project.

You will investigate some question about the abilities of language models. The report is expected to contain a brief literature review, motivation of your study, a description of what you did, and you found. It’s recommended to include quantitative validation of what you found, so that you show it’s not an illusion.

The report should have 8 pages of main report, plus unlimited appendix, in the NeurIPS style format. The main report should be self-contained, but you can use the appendix to report prompts, further analyses, or other material.

The report should be uploaded via CMS. The due date is October TBD, 2025, 23:59.

Everyone is expected to report on their project idea in the TBD, session, and to participate in discussion to give feedback to other students’ ideas. Feel free to come up with any ideas that might be interesting. Students may prepare a short slide deck on their idea. This will not be graded; the session is intended to help improve and finetune project ideas.

Contact

Please contact Xinting (xhuang@lst.uni-saarland.de) or Michael (mhahn@lst.uni-saarland.de) for any questions.

Accommodations

If you need any accommodations due to a disability or chronic illness, please either contact Michael at mhahn@lst.uni-saarland.de or the Equal Opportunities and Diversity Management Unit of the university.