# DR$^{3}$-Eval: Towards Realistic and Reproducible Deep Research Evaluation

> DR³-Eval is a new benchmark for evaluating research agents that uses static, multimodal sandboxes to balance realism and reproducibility, revealing hallucination as the primary failure mode.

- **Source:** [arXiv](https://arxiv.org/abs/2604.14683)
- **Published:** 2026-04-18
- **Permalink:** https://picx.dev/p/EVWC2p
- **Whiteboard:** https://picx.dev/p/EVWC2p/image

## Summary

# Summary (Overview)

*   **Proposes DR³-Eval:** A new benchmark designed for realistic, reproducible, and multimodal evaluation of Deep Research Agents (DRAs) focused on long-form, citation-grounded report generation. It addresses the tension between realism and reproducibility by using a static, per-task "sandbox corpus" that simulates the open web.
*   **Introduces a novel construction methodology:** Tasks are reverse-constructed from authentic, user-provided multimodal materials (text, image, video, audio) and a curated sandbox containing supportive, distractor, and noise documents. This ensures tasks have a verifiable solution path grounded in real-world complexity.
*   **Develops a multi-dimensional evaluation framework:** The benchmark assesses performance across five metrics: **Information Recall (IR)**, **Citation Coverage (CC)**, **Factual Accuracy (FA)**, **Instruction Following (IF)**, and **Depth Quality (DQ)**, validated for alignment with human judgment.
*   **Reveals critical challenges for state-of-the-art models:** Experiments with the developed **DR³-Agent** system and multiple LLMs (Claude Sonnet 4, GLM-4.7, Gemini-2.5-Pro, etc.) show the benchmark is highly challenging. Performance degrades with larger, noisier sandboxes, and the primary failure mode across models is **hallucination**, highlighting issues with evidence grounding in long-horizon tasks.

# Introduction and Theoretical Foundation

Recent advances in Large Language Models (LLMs) have enabled the development of **Deep Research Agents (DRAs)**. These systems aim to autonomously perform complex, long-horizon research tasks involving planning, iterative information retrieval, multimodal understanding, and the synthesis of structured, citation-grounded reports. Unlike traditional QA systems, DRAs must operate under uncertainty, reason over heterogeneous and noisy information, and integrate evidence into coherent analytical outputs.

However, evaluating these capabilities poses a significant challenge. Existing benchmarks suffer from key limitations:
*   **Real-time web access benchmarks** (e.g., DeepResearch Bench) offer realism but lack reproducibility due to temporal volatility and evaluation ambiguity.
*   **Curated document benchmarks** (e.g., DRBench) improve structure but often omit the noisy, misleading information common in real research.
*   **Sandbox-based benchmarks** (e.g., DeepResearchGym) ensure reproducibility but simplify the context to "clean," text-only data, lacking multimodal grounding and authentic user workflows.

This creates a gap between real-world research complexity—involving **multimodal user materials**, **noisy information**, and **implicit research intent**—and the environments used for evaluation. **DR³-Eval** is introduced to bridge this gap by reconciling realism, controllability, and reproducibility.

# Methodology

### 1. Dataset Construction Pipeline
The benchmark is constructed through a rigorous five-stage pipeline to ensure realism and verifiability.

**Stage 1: Grounding in Real-World Needs.** 100 authentic, multimodal document sets (50 English, 50 Chinese) were collected from paid volunteers across Technology, Economy, and Humanities domains (13 sub-fields). All materials underwent a two-stage sanitization protocol to remove Personally Identifiable Information (PII).

**Stage 2: Distilling Search Paths.** A "divergent-convergent" process uses an LLM (Gemini-2.5-Pro) to analyze source files and generate keywords.
*   **Divergent:** Generate 10 initial candidate keywords covering diverse facets.
*   **Convergent:** Classify keywords into:
    *   **Signal Keywords:** Point toward the core solution path.
    *   **Noise Keywords:** Thematically related but lead to irrelevant/misleading information.

**Stage 3: Building Research Sandbox.** A **static, per-task sandbox corpus** is built to ensure reproducibility. For each keyword, up to 100 web results are retrieved, deduplicated, and cleaned. Documents are categorized into three types:
1.  **Supportive Web Pages:** High-relevance results from *signal keywords*, manually verified to provide necessary and sufficient evidence.
2.  **Distractor Web Pages:** Also from *signal keywords*, but content is outdated, one-sided, or inaccurate.
3.  **Noise Web Pages:** Results from *noise keywords*.

A fine-grained difficulty scaling strategy creates sandboxes of five context lengths: **32k, 64k, 128k, 256k, and 512k tokens**. All settings include the full set of supportive pages. The number of distractors increases with context length, and the remaining quota is filled with noise pages.

**Stage我们发现 4: Constructing Query.** Using a **reverse construction method**, the final user query is synthesized based on the pre-determined evidential documents (supportive web pages and user files) and integrated with signal keywords. This ensures each query has a definitive, verifiable answer that requires joint reasoning across sources.

**Stage 5: Quality Control.** A four-dimensional validation protocol (Implicit Guidance, Synthesis Necessity, Insight Novelty, Interpretative Unambiguity) filters candidate tasks. From 280 initial candidates, 100 high-quality tasks remained (35.7% pass rate).

### 2. The DR³-Agent System
To demonstrate the benchmark's utility, the authors developed **DR³-Agent**, a multi-agent system adapted for the closed-world setting. It is based on the MiroFlow framework and features:
*   A **Main Agent** with integrated perception tools (for audio, video, etc.) that acts as a reasoning hub, running a "Plan-Act-Observe" loop.
*   Two specialized sub-agents:
    *   **RAG Search Sub-Agent:** Performs **iterative dense retrieval** within the static sandbox using the ReAct paradigm and query refinement, simulating heuristic web exploration.
    *   **File Reader Sub-Agent:** Parses long-text user files with fine-grained queries.

### 3. Evaluation Metrics
A multi-dimensional framework assesses performance in two dimensions: **Information Seeking** and **Report Generation**. GPT-5.1 (Φ) is used as the primary evaluator LLM, with Gemini-2.5-Pro as an assistant for multimodal content.

**Information Seeking Metrics:**
*   **Information Recall (IR):** Measures coverage of key insights extracted from user files ($I_{UF}$) and the sandbox corpus ($I_{SC}$).
    $$
    IR_{UF}(R, I_{UF}) = \frac{1}{|I_{UF}|} \sum_{i \in I_{UF}} \mathbb{1}[\text{cov}(i, R) = 1]
    $$
    $$
    IR_{SC}(R, I_{SC}) = \frac{1}{|I_{SC}|} \sum_{i \in I_{SC}} \mathbb{1}[\text{cov}(i, R) = 1]
    $$
    where $\text{cov}(i, R) \in \{1, 0.5, 0\}$.
*   **Citation Coverage (CC):** Measures the recall of documents strictly necessary for the query ($D_{req}$).
    $$
    CC(R, D_{req}) = \frac{|D_{req} \cap D_{cited}|}{|D_{req}|}
    $$
    where $D_{cited}$ are documents cited in report $R$.

**Report Generation Metrics:**
*   **Factual Accuracy (FA):** Verifies each claim-source pair $(c, s)$ in the report against its source.
    $$
    FA(R) = \frac{1}{|C|} \sum_{(c, s) \in C} V(c, s)
    $$
    where $V(c, s) = 1$ if source $s$ supports claim $c$, and $0$ otherwise.
*   **Instruction Following (IF):** Checks adherence to a checklist $L$ derived from the query.
    $$
    IF(R, L) = \frac{1}{|L|} \sum_{l \in L} S(l, R)
    $$
    where $S(l, R) \in \{1, 0\}$.
*   **Depth Quality (DQ):** An LLM judge scores the analytical substance and logical rigor of the report $R$ conditioned on query $Q$ and rubric $P$.
    $$
    DQ(R, Q) = \Phi(R, Q | P)
    $$

# Empirical Validation / Results

Experiments evaluated multiple state-of-the-art LLMs within the DR³-Agent framework across different sandbox corpus sizes.

### Main Results

**Table 2: Evaluation results on DR³-Agent.**
| Models | Information Seeking | | | Report Generation | | | Total Score |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| | **IR_UF** | **IR_SC** | **CC** | **FA** | **IF** | **DQ** | **Avg.** |
| | 64k | 128k | 512k | 64k | 128k | 512k | 64k | 128k | 512k | 64k | 128k | 512k | 64k | 128k | 512k | 64k | 128k | 512k | 64k | 128k | 512k |
| **Claude Sonnet 4** | 58.8 | 60.4 | 60.8 | 55.3 | 46.6 | 41.8 | 64.7 | 54.8 | 48.5 | 87.0 | 82.7 | 82.1 | 87.4 | 89.2 | 88.5 | 70.7 | 71.5 | 72.0 | **70.7** | **67.5** | **65.6** |
| **GLM-4.7** | 55.7 | 55.0 | 57.1 | 53.1 | 47.6 | 42.1 | 65.4 | 55.9 | 45.3 | 84.5 | 82.1 | 80.3 | 88.8 | 89.3 | 88.1 | 71.1 | 71.8 | 72.1 | 69.8 | 66.9 | 64.1 |
| **GLM-4.6** | 53.4 | 52.6 | 50.3 | 49.5 | 43.9 | 39.8 | 58.2 | 52.0 | 44.0 | 84.0 | 82.3 | 82.9 | 85.6 | 87.2 | 86.4 | 70.1 | 69.3 | 70.6 | 66.8 | 64.5 | 62.3 |
| **Gemini-2.5-Pro** | 43.9 | 45.7 | 42.9 | 37.7 | 35.1 | 30.8 | 54.3 | 49.5 | 36.6 | 81.3 | 80.7 | 80.0 | 84.9 | 84.5 | 84.5 | 67.1 | 68.3 | 67.4 | 61.5 | 60.6 | 57.0 |
| **GPT-4.1** | 40.7 | 42.5 | 41.3 | 30.9 | 29.4 | 29.2 | 37.2 | 35.6 | 30.0 | 56.4 | 54.2 | 58.8 | 83.0 | 83.3 | 82.7 | 63.1 | 63.2 | 63.4 | 51.9 | 51.3 | 50.9 |
| **Qwen3-235B-A22B** | 37.4 | 36.0 | 39.7 | 35.7 | 29.8 | 28.8 | 40.6 | 36.6 | 31.8 | 52.5 | 53.6 | 49.8 | 78.0 | 78.6 | 80.2 | 62.1 | 62.8 | 61.9 | 51.1 | 49.6 | 48.7 |
| **Qwen3-32B** | 33.2 | 36.6 | 35.4 | 26.5 | 25.3 | 24.7 | 34.2 | 32.3 | 26.1 | 49.4 | 52.2 | 51.5 | 73.5 | 74.2 | 74.3 | 58.8 | 59.9 | 59.3 | 45.9 | 46.7 | 45.2 |
| **Qwen3-30B-A3B** | 30.9 | 38.2 | 34.1 | 23.2 | 25.7 | 23.5 | 26.6 | 25.3 | 21.5 | 41.9 | 46.8 | 45.2 | 73.2 | 71.8 | 74.7 | 57.6 | 58.2 | 58.0 | 42.2 | 44.3 | 42.8 |

**Key Observations:**
1.  **DR³-Eval is challenging:** Claude Sonnet 4 performs best, but even top models show significant room for improvement. Scaling laws hold within model families.
2.  **Longer contexts lower performance:** As the sandbox grows from 64k to 512k tokens, performance (Avg., IR_SC, CC) drops across all models, indicating difficulty with noise and distraction.
3.  **Instruction Following ≠ Factual Accuracy:** Some models (e.g., Qwen3-235B, GPT-4.1) achieve good IF scores but very low FA, suggesting they generate "complete-looking" but unfounded reports.
4.  **Performance varies by domain:** As shown in Figure 4, model strengths differ across domains like Physics, Industry, and Finance.

### Further Analysis
*   **Evaluation Stability:** Bootstrap analysis and low score variance (e.g., SD of 0.83 for Claude Sonnet 4) confirm the benchmark's reliability. The difference between top models is statistically significant ($p = 0.0046$).
*   **Sandbox vs. Real Web:** Experiments replacing the sandbox with real-time web search show close performance (Table 3), indicating the sandbox preserves core information difficulty and is a reliable substitute.
*   **Sandbox Design Effectiveness:** Ablation studies (Figure 5) confirm that **distractor documents** effectively increase task difficulty, and the sandbox contains no other effective information beyond the designated supportive documents.
*   **LLM-as-Judge Alignment:** The automated scoring shows strong correlation with human evaluation (Table 4).
    **Table 4: LLM-as-judge vs. human evaluation.**
    | Method | $r$ (Pearson) | $\rho$ (Spearman) | Agreement |
    | :--- | :--- | :--- | :--- |
    | DR³-Eval (Ours) | 0.78 | 0.73 | 0.89 |
    | Inter-Human | 0.83 | 0.76 | 0.91 |
*   **Retrieval and Error Analysis:**
    *   **Different Retrievers:** Vector-based retrieval (OpenAI text-embedding-3-small) outperforms lexical methods (BM25) (Table 5).
    *   **Agentic-RAG Turns:** Increasing maximum iteration turns for the RAG sub-agent improves performance, but excessive turns can cause a decline (Table 6).
    *   **Error Attribution:** Analysis of 100 reports per model (Figure 8) reveals that **hallucination is the primary failure mode** for most models (48%-77% of errors), indicating the key challenge is evidence grounding, not just evidence acquisition.

# Theoretical and Practical Implications

**Theoretical Implications:**
*   **Advances Benchmark Design:** DR³-Eval provides a principled framework for evaluating long-horizon research capabilities, balancing the often conflicting goals of realism, controllability, and reproducibility.
*   **Highlights Model Limitations:** The benchmark systematically exposes critical failure modes in current LLMs, particularly **hallucination under information overload** and **retrieval robustness** in noisy environments. It shows that scaling alone is insufficient for complex research tasks.
*   **Validates Multi-dimensional Evaluation:** The proposed metric suite, validated against human judgment, demonstrates the necessity of moving beyond single-score assessments to understand different facets of research agent performance.

**Practical Implications:**
*   **For DRA Development:** Offers a reproducible testbed for diagnosing and improving agents, especially in areas of retrieval strategy, citation grounding, and hallucination mitigation.
*   **For Sustainable AI Research:** By using a static sandbox instead of live web crawling for every evaluation, the framework promotes more computationally efficient and environmentally sustainable benchmarking.
*   **For Ethical AI Development:** The focus on **Factual Accuracy** and **Citation Coverage** steers the field towards developing verifiable and reliable systems, potentially mitigating risks from persuasive but unfounded AI-generated content.

# Conclusion

DR³-Eval addresses key limitations in evaluating Deep Research Agents by introducing a benchmark grounded in authentic user scenarios, constructed with a controlled yet web-like sandbox, and employing a reverse-construction method to eliminate ambiguity. Experimental results demonstrate that the benchmark poses substantial challenges to state-of-the-art LLMs, with performance degrading in larger, noisier environments and **hallucination emerging as the predominant failure mode**. This indicates that the main bottleneck for current models lies in the **stability of evidence utilization** during long-form generation, not merely evidence acquisition.

The work provides a foundation for more rigorous, reproducible, and diagnostically useful evaluation of autonomous research systems, guiding future development towards greater reliability and safety.

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