Deep research agents increasingly interleave web browsing with multi-step computation, yet existing benchmarks evaluate these capabilities in isolation, creating a blind spot in assessing real-world performance. We introduce DRBENCHER, a synthetic benchmark generator for questions that require both browsing and computation, synthesized answer-first from knowledge-graph chains with no seed passages or provenance text. It enforces four criteria: verifiability (gold answers are computed by executing parameterized code over knowledge-graph values), complexity (multi-hop entity identification, property retrieval, and domain-specific computation), difficulty (a two-stage verification cascade filters out questions solvable by the generating model), and diversity (a greedy max-min embedding filter maximizes coverage). These criteria are realized via a unified answer-first pipeline spanning five domains: biochemistry, financial, geophysical, security, and history. Human evaluation shows 76% validity, with 35% of errors due to outdated knowledge-graph entries, highlighting an inherent limitation of systems that reason over evolving data. Automatic evaluation shows that the strongest frontier model achieves only 20% answer accuracy. Compared to manually constructed benchmarks (BrowseComp+, MATH-500, GPQA), DRBENCHER achieves the highest semantic diversity. We release DrBencher pipeline and the human-verified benchmark data at https://github.com/IBM/DrBencher.
Figures & tables
Figure 1: The unified DrBencher pipeline, shared across all five domains ( biochemistry , financial , geophysical , history , security ). A running example using Mount Fuji (atmospheric pressure template) illustrates each stage.
Benchmark
Multihop
HybridQ
Prog. gold
Syn
KG
Comp. calib.
HotpotQA ( Yang et al., 2018 )
✓
✗
✗
✗
✗
✗
MATH ( Hendrycks et al., 2021b )
✗
✗
✓
✗
✗
✗
MuSiQue ( Trivedi et al., 2022 )
✓
✗
✗
✗
✗
✗
LC-QuAD ( Trivedi et al., 2017 )
✓
✗
✗
✗
✓
✗
GAIA ( Mialon et al., 2024 )
✓
✗
✗
✗
✗
✗
AutoBencher ( Li et al., 2025 )
✗
✗
✗
✓
✗
✗
Table 1: Comparison of DrBencher with related benchmarks. HybridQ = each question jointly requires retrieval and computation, Prog. gold = programmatic gold answer, Syn = questions are synthetically generated, KG = clue facts verified against knowledge graph and Wikipedia, Comp. calib. = complexity calibration. ✓ = supported, ✗ = not supported.
Figure 2: CCI illustrated for two questions. (a) E=1,P=1 (CCI = 2): the model identifies one entity (Zugspitze) and retrieves one property (elevation). (b) E=1,P=2 (CCI = 3): the model identifies one entity (Los Ángeles, Chile) but must retrieve two properties (population and area) to apply the population density template.
Table 3: Human verification accuracy and error breakdown. n : questions after diversity filtering; Err: total errors; Acc: accuracy (%); Acc*: accuracy excluding DB errors (%). Error categories—DB: incorrect/stale KG data; LLM: LLM hallucination in fact extraction or question composition; MH: multi-hop property flattening; Amb: ambiguous or non-unique entity description; Ent: entity misidentification.
Biochem
Financial
Geophysical
History
Security
All
n
37
69
65
62
35
268
Model
Ent
Ans
Ent
Ans
Ent
Ans
Ent
Ans
Ent
Ans
Ent
Ans
Claude Opus 4.6
80.2
35.1
94.2
10.6
77.4
20.0
82.8
30.6
98.1
4.8
86.1
20.1
Gemini 2.5 Flash
57.7
28.8
88.9
7.7
72.3
26.7
79.6
24.7
81.0
1.9
77.4
18.4
GPT-5.2
67.6
14.4
93.7
3.9
79.5
10.3
77.4
22.0
87.6
0.0
82.1
10.6
Llama 4 Maverick
64.0
27.9
82.1
6.3
69.7
21.5
81.7
30.6
74.3
1.0
75.5
17.9
Table 4: Entity identification (Ent) and answer accuracy (Ans) (%) across five DrBencher domains. Top: proprietary models; bottom: open-weight. Each model accuracy is the average of 3 runs. McNemar’s test (All, N=268 , majority vote over 3 runs): Opus, Gemini, and Llama form a statistical tie (pairwise p > 0.05); Opus significantly outperforms GPT5.2, Qwen, and Mistral at p < 0.001.
Table 7
Domain
GPT
Llama
Shared
%GPT ⊆ Llama
Gold
Biochem
21
41
16
76.2
16/16
Financial
18
37
13
72.2
13/13
Geophysical
41
61
31
75.6
31/31
History
21
34
18
85.7
18/18
Security
12
20
11
91.7
11/11
Total
113
193
89
78.8
89/89
Table 7: Difficulty-filter ablation: gpt-oss-120b vs. Llama 4 Maverick as the V1/V2 verifier, with question generation held fixed. GPT/Llama: questions surviving each filter; Shared: retained by both; %GPT ⊆ Llama: fraction of gpt-oss-120b ’s set also in Llama’s; Gold: matching gold answers among shared questions. Gold answers match exactly (89/89), confirming answer-level model independence.
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Parameter
Value
Architecture
MoE, 120B parameters
Quantization
MXFP4
Precision
bfloat16
Tensor parallel size
8
GPU memory utilization
0.9
Max sequence length
131,072 tokens
Appendix
Table 8: Model serving configuration.
Parameter
V1
V2
Samples per question ( n )
10
10
Sampling temperature
0.7
1.0
Accuracy threshold ( τ )
0.5
0.5
Max agentic iterations ( K )
—
200
Tool timeout
—
60 s
Answer tolerance ( ϵ )
5%
Appendix
Table 9: Verification hyperparameters. V1: closed-book; V2: agentic with tool calls. ϵ=5% relative tolerance is used during generation-time difficulty filtering; a stricter 2% tolerance is applied during evaluation scoring (Section 5.2 ).
Family
Template
Computation
Properties
Unit
Quantitative modeling
Exponential growth
⌊P(1+r)t⌉
P1082
people
Quantitative modeling
GDP per capita
G/P
P2131, P1082
USD
Scientific inference
Surface gravity
GM/r2
P2067, P2120
m/s 2
Scientific inference
Atmospheric pressure
P0e−Mgh/RT/1000
P2044
kPa
Appendix
Table 10: Representative reasoning templates (4 of 37)
Figure 3: Representative page from the human annotation interface. The tool displays the question, gold answer, gold entity chain, computation code, and grounding evidence with semantic highlighting ( blue : question-relevant entities; green : answer-relevant values). Annotators assign a binary verdict and optional comment.
Domain
n
Agr.
α
Geophysical
47
78.7
0.25
History
30
86.7
0.43
Biochemistry
32
68.8
0.10
Security
11
81.8
0.56
Financial
39
69.2
0.36
Overall
159
76.1
0.30
Appendix
Table 11: Inter-annotator agreement across all five domains. n : questions with overlapping annotations from two annotators; Agr.: raw agreement (%); α : Krippendorff’s alpha. Overall statistics are weighted by domain size.
Disagreement source
Count
%
LLM hallucination / factual error (only)
18
47.4
Question ambiguity / non-uniqueness (only)
8
21.1
Both ambiguity + hallucination
7
18.4
Stale KG data
4
10.5
Unclassified
1
2.6
Total
38
100.0
Appendix
Table 12: Breakdown of all 38 inter-annotator disagreements (of 159 matched pairs). Disagreements concentrate in subjective categories (hallucination, ambiguity); objectively verifiable stale data accounts for only 10.5%.
Parameter
Value
Samples per question ( n )
3
Temperature
model default (omitted)
Max response tokens
8,192
Answer tolerance
2% relative (exact for history)
Retry on failure
5 attempts, exponential backoff
Appendix
Table 13: Evaluation inference configuration.
Opus
Gem.
GPT
Llm.
Qwn.
Mst.
4.6
2.5
5.2
4 Mav
3
Sm.
Answer acc. (%)
20
17
10
16
8
6
Failures ( n )
214
222
242
224
247
251
Failure breakdown (% of each model’s failures):
Property retrieval
64.0
45.5
54.5
51.8
38.5
51.8
True calculation
15.0
0.5
0.0
19.6
2.4
0.0
Appendix
Table 14: Two-stage failure analysis over the 268 questions (majority vote, 3 runs). Rows below the rule are percentages of each model’s failures. Property/formula (indet.): entity correctly identified and answer wrong, but the reasoning trace was insufficient to distinguish a wrong property value from a wrong formula. Models: Claude Opus 4.6, Gemini 2.5 Flash, GPT-5.2, Llama 4 Maverick, Qwen3-30B-A3B, Mistral-Small-3.2-24B.
Opus
Gemini
GPT5.2
Llama
Qwen
Gemini
0.243
GPT5.2
<.001 ∗∗∗
<.001 ∗∗∗
Llama
0.155
0.868
0.004 ∗∗
Qwen
<.001 ∗∗∗
<.001 ∗∗∗
0.404
<.001 ∗∗∗
Mistral
<.001 ∗∗∗
<.001 ∗∗∗
0.095
<.001 ∗∗∗
0.522
Appendix
Table 15: McNemar’s test p-values for answer accuracy (All N=268 ). Per-question correctness is determined by majority vote across 3 runs. ∗∗ p < 0.01, ∗∗∗ p < 0.001.
Domain
n
Mean
Med.
CCI=2
CCI=3
CCI=4
CCI=6
Geophysical
65
2.35
2
53
3
8
1
Biochemistry
37
2.81
2
20
4
13
0
History
62
2.82
3
24
25
13
0
Financial
69
2.84
2
37
10
20
2
Security
35
3.49
4
3
12
20
0
Appendix
Table 16: CCI distribution by domain. Mean: mean CCI; Med.: median CCI.
CCI
Biochem
Financial
Geophysical
History
Security
All
2
34.7 (20)
6.0 (37)
13.9 (53)
37.5 (24)
5.6 (3)
18.8
3
6.9 (4)
6.1 (10)
31.5 (3)
15.6 (25)
2.3 (12)
11.1
≥ 4
6.8 (13)
4.8 (22)
11.1 (9)
20.5 (13)
0.6 (20)
7.4
Appendix
Table 17: CCI-controlled accuracy (%) by domain (number of questions in parentheses). Each cell is the average across 6 models × 3 runs.
Figure 4: Representative QA pairs from the Financial (top) and Security (bottom) domains.