TURTLEAI: Benchmarking Multimodal Models for Visual Programming in Turtle Graphics

Chao Wen, Jacqueline Staub, Adish Singla


Abstract
Vision-language models (VLMs) have been explored for visual programming, where they generate code to solve visual tasks. However, most prior work focuses on visual programming for productivity; it remains unclear how well current VLMs perform on education-oriented visual programming and what factors limit their performance. To bridge this gap, we introduce TURTLEAI, a benchmark containing 823 tasks curated based on real-world visual programming tasks in the Turtle Graphics domain. Solving these tasks requires models to perceive geometric patterns, reason about spatial relationships, and synthesize Python code that faithfully reproduces geometric patterns. We evaluate 20+ VLMs, including GPT-5, GPT-4o, and Qwen2-VL-72B, and find that they struggle significantly, with most achieving success rates below 30%. To address these limitations, we propose a data generation technique that requires only a small set of seed samples. Fine-tuning Qwen2-VL-72B on the resulting synthetic data yields an improvement of about 20% on real-world tasks. Our failure analysis reveals that GPT-4o struggles with spatial reasoning and precise visual replication, whereas fine-tuning primarily improves the alignment between visual reasoning and code implementation.
Anthology ID:
2026.findings-acl.334
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
Note:
Pages:
6719–6756
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.334/
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Bibkey:
Cite (ACL):
Chao Wen, Jacqueline Staub, and Adish Singla. 2026. TURTLEAI: Benchmarking Multimodal Models for Visual Programming in Turtle Graphics. In Findings of the Association for Computational Linguistics: ACL 2026, pages 6719–6756, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
TURTLEAI: Benchmarking Multimodal Models for Visual Programming in Turtle Graphics (Wen et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.334.pdf
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