Establishing common ground, a shared set of beliefs and mutually recognized facts, is fundamental to collaboration, yet remains a challenge for current AI systems, especially in multimodal, multiparty settings, where the collaborators bring different information to the table. We introduce the Distributed Partial Information Puzzle (DPIP), a collaborative construction task that elicits rich multimodal communication under epistemic asymmetry. We present a multimodal dataset of these interactions, annotated and temporally aligned across speech, gesture, and action modalities to support reasoning over propositional content and belief dynamics. We then evaluate two paradigms for modeling common ground (CG): (1) state-of-the-art large language models (LLMs), prompted to infer shared beliefs from multimodal updates, and (2) an axiomatic pipeline grounded in Dynamic Epistemic Logic (DEL) that incrementally performs the same task. Results on the annotated DPIP data indicate that it poses a challenge to modern LLMs' abilities to track both task progression and belief state.
Figures & tables
Figure 1: A builder and 3 directors participating in the DPIP task with a partially-completed structure on the table. Director 1 (second from left) is indicating the position of a block using a gesture as well as a speech act.
Figure 2: 3 individual side views of the same complete structure, each assigned to a director.
Ave
SD
Ave*
SD*
Min
Max
Max*
Total
Task Time (s.)
703.53
903.48
423.52
190.43
159.82
3223.60
800.40
7035.32
# Utterances
311.20
397.90
190.33
117.34
38
1399
350
3112
# Actions
47.90
48.34
33.00
11.48
19
182
53
479
# Gestures
27.80
19.74
22.56
11.35
7
75
37
278
# Props
30.70
15.54
26.44
8.23
18
69
40
307
# Tokens
1302.70
1442.70
860.44
375.71
350
5283
1517
13027
Table 1: Summary statistics of 10 annotated DPIP Lego task groups. *Indicates statistics excluding outlier group (Sec. 3.2 ).
Group
3
4
5
7
9
10
11
12
13
14
Ave
Speech
1.000
0.979
1.000
0.990
1.000
1.000
0.832
1.000
0.908
1.000
0.971
Structure
0.826
0.943
0.901
0.939
1.000
0.587
0.924
0.890
0.916
1.000
0.893
Gesture (union)
0.578
0.540
0.638
0.507
0.568
0.542
0.526
0.378
0.452
0.222
0.495
Gesture (intersection)
0.944
0.882
0.839
0.854
0.853
0.795
0.793
0.806
0.886
0.800
0.845
Table 2: Inter-annotator agreement (IAA) scores by modality across 10 groups.
Actions → Structure
Group
3
4
5
9
10
11
12
13
14
μ
SD
Llama 3.2-3B
Average
0.173
0.202
0.170
0.275
0.157
0.402
0.259
0.134
0.200
0.219
0.078
Global
0.000
0.037
0.056
0.056
0.000
0.148
0.074
0.037
0.037
0.049
0.042
Qwen3-4B
Average
0.185
0.193
0.232
0.457
0.235
0.392
0.276
0.251
0.264
0.276
0.085
Global
0.037
0.000
0.148
0.185
0.074
0.148
0.148
0.037
0.185
0.107
0.066
GPT-5-mini / GPT-5
Average
0.343
0.270
0.308
0.633
0.254
0.561
0.333
0.362
0.378
0.382
0.122
Global
0.133
0.148
0.000
0.482
0.000
0.222
0.000
0.000
0.444
0.159
0.180
Table 3: Results in four experimental conditions for all models, methods, and metrics (DSC).
Aligned → Structure
Llama 3.2-3B
Qwen3 -4B
GPT-5-mini / GPT-5
Average
0.040
0.066
0.007
Global
0.182
0.298
0.055
CGC → Structure
Average
0.250
Global
0.226
Aligned → CGC
Llama 3.2-3B
Qwen3 -4B
GPT-5-mini / GPT-5
Table 4: DSC Results in three experimental conditions for outlier group, Group 7.
Fruitful collaborations require effective communication of privately-held information. The increasing use of LLMs as "collaborators" raises questions about the extent to which they exhibit these pragmatic capabilities. In this paper, we perform a novel investigation into the pragmatic reasoning capabilities of LLMs in a multiparty collaborative task under partial information conditions. We first formalize a notion of collaborative epistemic asymmetry and prove that fully actionable instructions in this context requires adherence to Grice's cooperative principle. We then empirically assess various LLMs' abilities to act cooperatively as both speakers and listeners, including both prompting and post-training strategies. Our results show that while LLMs exhibit certain pragmatic capabilities in collaborative settings, they still face challenges in pragmatic communication with incomplete information, and that Grice's maxims predict distinct failure modes.
Epistemic reasoning requires agents to infer the state of the world from partial observations and information about other agents' knowledge. Prior work evaluating LLMs on epistemic puzzles often frames failures as memorization rather than reasoning. We argue that this dichotomy is too coarse for newer models: memorization is a limiting case of pattern-based reasoning, where a model matches a task to a familiar template and applies the corresponding solution. We introduce a two-dimensional benchmark over Dynamic Epistemic Logic (DEL) puzzles, separating narrative familiarity from inference complexity, which allows us to distinguish pattern-based from epistemic reasoning. We find that models are substantially more robust to surface form changes than prior work suggested, yet consistently struggle in asymmetric settings where familiar patterns no longer apply and success requires tracking fragmented epistemic states. Code, datasets, and evaluation results are available at https://github.com/adigabay84/del-puzzles-benchmark.
Adi Gabay, Gabriel Stanovsky, Liat Peterfreund
School of Computer Science and Engineering The Hebrew University of Jerusalem
While Large Language Model (LLM) agents are often approached from the angle of action planning/generation to accomplish a goal (e.g., given by language descriptions), their abilities to collaborate with each other to achieve a joint goal are not well explored. To address this limitation, this paper studies LLM agents in task collaboration, particularly under the condition of information asymmetry, where agents have disparities in their knowledge and skills and need to work together to complete a shared task. We extend Einstein Puzzles, a classical symbolic puzzle, to a table-top game. In this game, two LLM agents must reason, communicate, and act to satisfy spatial and relational constraints required to solve the puzzle. We apply a fine-tuning-plus-verifier framework in which LLM agents are equipped with various communication strategies and verification signals from the environment. Empirical results highlight the critical importance of aligned communication, especially when agents possess both information-seeking and -providing capabilities. Interestingly, agents without communication can still achieve high task performance; however, further analysis reveals a lack of true rule understanding and lower trust from human evaluators. Instead, by integrating an environment-based verifier, we enhance agents' ability to comprehend task rules and complete tasks, promoting both safer and more interpretable collaboration in AI systems. https://github.com/Roihn/EinsteinPuzzles
Run Peng, Ziqiao Ma, Amy Pang +5
University of Michigan · UNC, Chapel Hill · Georgia Tech +2