Lacuna: A Research Map for Machine Learning Problem Formulation

Research problem formulation is the cognitive task of turning a vague scientific idea into a testable hypothesis. \textbf{Lacuna} is a research map that supports this process for machine learning, using LLMs to turn papers and scholarly metadata into markdown summaries, concept elements, research directions, author and venue pages, and research proposals. Each item keeps links to the primary source records and papers that support it. We release the map with web, markdown, and MCP interfaces, plus scripts for reproducing the agent run. On a theorem-proving seed idea, the agent reaches a research proposal in 85.5 seconds and 7 tool calls, vs.\ 289.2 seconds and 27 tool calls for a sequential-PDF baseline. On ScholarQA-CS-ML, an ML/AI subset of the OpenScholar benchmark, Lacuna-GPT-4o scores 0.694 under the ScholarQABench rubric judge, compared with 0.672 for the OpenScholar-GPT-4o baseline on the same questions.