Knowledge-based assets play a very important role in the Information Age. How to organize existing knowledge and present to the user properly are important research issue for decision support. Previous literature has indicated that multiple documents can be organized in different ways and different modes of knowledge presentation may result in different learning effects. Typical presentation modes include textual summarization and graphical presentation. The purpose of this thesis is to evaluate whether textual and graphical presentations of a news event may result in different effects for the user. In particular, this study is focused on comparing the textual summary and ontology-base graphical presentation and use the Bloom Theory of Educational Objectives to measure the learning effect of the user An experiment was conducted to assess the knowledge and cognitive process dimension in the Bloom¡¦s theory. We also measured the learning time, system quality, content quality, and overall satisfaction. The result shows that the textual system performed better in learning factual knowledge, and the ontology-base system performed better in learning conceptual and procedural knowledge.