xml keyword search provides a simple and user-friendly way of retrieving data from xml databases, but the ambiguities of keywords make it difficult to effectively answer keyword queries. XReal [4] utilizes the statistics of underlying data to resolve keyword ambiguity problems. However, we found their proposed formula for inferring the search-for node type suffers from inconsistency and abnormality problems. In this paper, we propose a dynamic reduction factor scheme as well as a novel algorithm DynamicInfer to resolve these two problems. Experimental results are provided to verify the effectiveness of our approach.