SignTrace: Describe a Sign, Find the Word

SignTrace, a natural-language reverse-lookup system for a Chinese sign-language dictionary of 6,699 entries, achieved 94.0% Hit@1, 97.4% Hit@9, and a mean reciprocal rank of 0.9540 on a 500-query dictionary-derived benchmark, according to an arXiv paper (2609.30295v1). The system combines LLM-based dictionary enrichment, action extraction, dictionary-style rewriting, seven-channel retrieval, and candidate reranking, which raised Hit@1 from 71.8% to 94.0%; median query-processing time was 13.37 seconds with six concurrent queries. SignTrace has been deployed for user trials with positive informal feedback, though the authors note the dictionary-derived wording and prior selection in the benchmark limit generalization to descriptions independently produced by users.

arXiv:2609.30295v1 Announce Type: new Abstract: Identifying an unfamiliar sign is difficult when a learner remembers its movement but does not know its meaning or formal feature codes. SignTrace addresses this longstanding reverse-lookup problem through natural-language access to a Chinese sign-language dictionary. The system integrates LLM-based dictionary enrichment, action extraction, dictionary-style rewriting, seven-channel retrieval, and candidate reranking over 6,699 entries. It has been deployed for user trials and has received positive informal feedback. Evaluation on a dictionary-derived benchmark of 500 movement-description queries yields 94.0% Hit@1, 97.4% Hit@9, and a mean reciprocal rank of 0.9540. Reranking increases Hit@1 from 71.8% to 94.0%, while component analyses show the contribution of enriched entry descriptions. Median query-processing time is 13.37 seconds with six concurrent queries. By connecting everyday movement descriptions to documented signs and meanings, SignTrace provides a practical tool for identifying unfamiliar signs. Dictionary-derived wording and prior selection within the benchmark limit generalization to descriptions independently produced by users.