Thematic maps are widely used to communicate spatial patterns to non-expert audiences. Although uncertainty is inherent in thematic map data, it is rarely visualized, raising questions about how its inclusion affects trust. Prior work offers mixed perspectives: some argue that uncertainty fosters trust through transparency, while others suggest it may reduce trust by introducing confusion. Yet few empirical studies explicitly measure trust in thematic maps. We conducted a between-subjects experiment (N=161) to evaluate how visualizing uncertainty at varying levels (low, medium, high) influences trust. We find that uncertainty visualization generally reduces trust, with greater reductions observed as uncertainty levels increase. However, maps dominated by low uncertainty do not significantly differ in trust from those with no uncertainty. Moreover, while uncertainty visualization tends to make readers question the accuracy of the data, it appears to have a weaker influence on perceptions of the mapmaker's integrity.

翻译：专题地图被广泛用于向非专业受众传达空间分布模式。尽管不确定性是专题地图数据固有的特性，但其可视化呈现却较为罕见，这引发了关于纳入不确定性如何影响信任度的问题。现有研究提供了不同的观点：一些学者认为不确定性通过提高透明度来增强信任，而另一些研究则表明它可能因引入混淆而降低信任。然而，明确测量专题地图信任度的实证研究仍然有限。我们进行了一项被试间实验（N=161），以评估不同水平（低、中、高）的不确定性可视化如何影响信任度。研究发现，不确定性可视化通常会降低信任度，且随着不确定性水平的增加，信任度下降更为明显。然而，以低不确定性为主的专题地图与完全不显示不确定性的地图在信任度上并无显著差异。此外，虽然不确定性可视化往往使读者质疑数据的准确性，但它对地图制作者诚信度的感知影响较弱。