In this experiment, rough ontology based Semantic information retrieval is compared with precise ontology based semantic information retrieval and keyword based syntax information retrieval based on the chosen data set.
Based on the consistency of comparison conditions, a user should input the same keyword in these different systems. But, within the acceptable retrieval time range, the results show that the recall ratio and precision ratio of rough ontology based semantic information retrieval are evidently superior to the other two methods. For example, if it retieves “Crowded port”, top five retrieval results of syntax retrieval, precise ontology based semantic retrieval and rough ontology based semantic retrieval are shown in TABLE II respectively.