Nowadays, Web-based learning systems have become popular because they can provide multiple tools, among which hierarchical maps are widely used to support teaching and learning. However, traditional hierarchical maps may let learners easily get lost within large information space. This study proposes an animated hierarchical map to address this problem. To consider the effects of different instructional approaches, we also conducted an empirical study to examine how learners in collaborative learning and those in individual learning reacted differently to the animated hierarchical map and traditional hierarchical map. A questionnaire, which was designed based on Nielsen's heuristics, was applied to examine learners' reactions to the proposed animated hierarchical map. The results show that the proposed animated hierarchical map is generally better than the traditional hierarchical map but the effects on individual learning is limited.