Summary
This paper presents a novel approach to knowledge editing in large language models (LLMs), specifically targeting unstructured knowledge. The authors argue that current knowledge editing methods are limited in their ability to handle the complex and free-from information found in unstructured formats, which constitute a significant portion of real-world knowledge.
The key contributions of this paper are as follows:
1. **Unstructured Knowledge Editing (UnKE) Method**: The authors propose UnKE, a method that extends knowledge editing from structured knowledge to unstructured knowledge. This is a advancement as it addresses the gap in handling the majority of real-world knowledge that is not neatly packaged in structured formats.
2. **Cause-Driven Optimization**: The paper replaces term-driven optimization with a cause-driven approach, which edits the last token directly while preserving context. This avoids the need to locate specific terms and prevents the loss of contextual information, which is a common issue with term-driven methods.
3. **UnKEBench Dataset**: To evaluate the performance of UnKE, the authors develop a new benchmark dataset, UnKEBench, which is designed to be more challenging than existing structured editing benchmarks due to the complexity of unstructured knowledge.
4. **Experimental Results**: The paper demonstrates that UnKE outperforms baselines on the newly proposed UnKEBench dataset, as well as on KEBench.
5. **Robustness Analysis**: The authors conduct robustness analysis experiments, confirming UnKE's ability to perform batch and sequential editing, and its superiority over baseline models in structured knowledge editing.
In summary, this paper makes a compelling case for the need to extend knowledge editing to unstructured data and provides a robust method and benchmark to facilitate this advancement. The proposed UnKE method shows promising results in accurately handling free-format unstructured knowledge, which is a good step forward for the field of knowledge editing in LLMs.
Strengths
**Originality:**
- The paper introduces an approach to editing unstructured knowledge within large language models (LLMs), which is a novel contribution to the field.
- The proposal of the Unstructured Knowledge Editing (UnKE) method breaks new ground by extending the scope of knowledge editing beyond traditional structured knowledge.
- The concept of non-local block key-value storage and cause-driven optimization is innovative and addresses a previously unmet need for handling complex, unstructured information.
- The authors have developed a new benchmark dataset, UnKEBench, which provides a way to assess unstructured knowledge editing capabilities.
**Clarity:**
- The paper is well-organized and clearly structured, making it easy for readers to follow the progression of ideas and the logical flow of arguments.
**Significance:**
- The successful editing of unstructured knowledge has broad implications for various applications, including but not limited to information retrieval, question answering, and conversational agents.
- By demonstrating UnKE's effectiveness on both newly proposed and traditional datasets, the paper highlights the potential of the method to impact real-world applications where unstructured knowledge is prevalent.
Overall, the paper is a significant contribution to the field of knowledge editing, particularly in the area of knowledge editing within LLMs.
Weaknesses
- Lack of baselines: Although UnKE has demonstrated quite good results, the baselines used for comparison are not the most advanced methods in the field. It would be more convincing if UnKE could be compared with state-of-the-art methods such as WISE, GRACE, and FT-M, and show better results. In particular, UnKE should against with non-term-driven optimization method GRACE for a more fairly comparison.
- Contributions of UnKEBench: First, before UnKEBench, there have already been works on long-form knowledge editing (e.g., LEME[1]), but this is not discussed in the paper. Second, UnKEBench is generated by ChatGPT and lacks steps to ensure data quality, such as human verification.
- Description inconsistent with reality:
- The paper hypothesizes that unstructured knowledge is distributed across multiple layers of the language model, but the experiment only edits one layer.
- The paper claims that UnKE's cause-driven optimization can preserve pre-trained knowledge during the editing process. However, in the experiments, UnKE's ability to retain original knowledge is worse than the baseline (i.e., MMLU in Table 2 and Src-Acc and Tgt-Acc in Table 3).
[1] Rosati D, Gonzales R, Chen J, et al. Long-form evaluation of model editing[J]. arXiv preprint arXiv:2402.09394, 2024.
Questions
- Why does unstructured knowledge contain more information? Intuitively, unstructured knowledge has more grammatical and structural words, which carry low information.
- What is the relationship between LEME and UnKEBench? If LEME and UnKEBench have similar contributions, the statement "the lack of a benchmark for editing unstructured knowledge" in the paper would not hold.
- In "EXPERIMENTS ON STRUCTURED KNOWLEDGE EDITING," why choose KEBench instead of knownedit? How does UnKE perform on knownedit?