ResearchCube: Multi-Dimensional Trade-off Exploration for Research Ideation

Research ideation requires navigating trade-offs across multiple evaluative dimensions, yet most AI-assisted ideation tools leave this multi-dimensional reasoning unsupported, or reducing evaluation to unipolar scales where "more is better". We present ResearchCube, a system that reframes evaluation dimensions as bipolar trade-off spectra (e.g., theory-driven vs. data-driven) and renders research ideas as manipulable points in a user-constructed 3D evaluation space. Given a research intent, the system proposes candidate bipolar dimension pairs; users select up to three to define the axes of a personalized evaluation cube. Four spatial interactions -- AI-scaffolded dimension generation, 3D navigation with face snapping, drag-based idea steering, and drag-based synthesis -- enable researchers to explore and refine ideas through direct manipulation rather than text prompts. A qualitative study with 11 researchers revealed that (1) bipolar dimensions served as cognitive scaffolds that externalized evaluative thinking and offloaded working memory, (2) the spatial representation provided a sense of agency absent in chatbot-based AI tools, (3) participants desired fluid transitions across dimensionality levels -- from single-dimension focus to more than three dimensions, and (4) a productive tension emerged between AI-suggested starting dimensions and users' evolving desire for control. We distill these findings into design implications for multi-dimensional research ideation tools, including progressive dimensional control, fluid dimensionality, and transparent synthesis with provenance.