Existing conversational search systems can synthesize information into responses, but they lack principled ways to adapt response formats to users' cognitive states. This paper investigates whether aligning format and distance, which involves matching information granularity and media to users' psychological distance, improves user experience. In a between-subjects experiment (N=464) on travel planning, we crossed two distance dimensions (temporal/spatial x near/far) with four formats varying in granularity (abstract/concrete) and media (text/image-and-text). The experiment established that format--distance alignment reduced users' risk perceptions while increasing decision confidence, perceptions of information usefulness, ease of use, enjoyment, and credibility, and adoption intentions. Concrete formats imposed higher cognitive load, but yielded productive effort when matched to near-distance tasks. Images enhanced concrete but not abstract text, suggesting multimedia benefits depend on complementarity. These findings establish format--distance alignment as a distinctive and important design dimension, enabling systems to tailor response formats to users' psychological distance.

翻译：现有对话式搜索系统虽能合成信息生成回复，但缺乏根据用户认知状态调整响应格式的原则性方法。本文研究格式与距离的对齐——即将信息粒度与媒介匹配至用户心理距离——是否能够改善用户体验。在一项旅游规划任务的组间实验（N=464）中，我们交叉操纵了两个距离维度（时间/空间 × 近/远）与四种不同粒度（抽象/具体）和媒介（纯文本/图文结合）的格式。实验证实：格式-距离对齐能降低用户的风险感知，同时提升决策信心、信息有用性感知、易用性感知、愉悦感、可信度及采纳意愿。具体格式会带来更高的认知负荷，但在匹配近距离任务时能产生建设性认知投入。图像能增强具体文本的效果，但对抽象文本无显著提升，表明多媒体效益取决于互补性。这些发现确立了格式-距离对齐作为一个独特且重要的设计维度，使系统能够根据用户心理距离定制响应格式。