Abstract: In the retrieval results, the hierarchical relationship of knowledge is hidden. We use hLDA
model to analyze the hierarchical topic, reveal the path of the topic in the retrieval results, and thus
provide knowledge service of high quality. First, we realize the preprocessing of the retrieval results by
building the professional knowledge database. Secondly, we obtain the hierarchical topic structure through
reasonable super parameter sampling. Lastly, combined with visualization technology, we describe the
hidden knowledge of academic information retrieval. Experiments show that this method is effective for
visual analysis of retrieved results. Compared with the classical hierarchical clustering method, the results
are more readable.

Key words: hLDA, LDA, Retrieval results, Visualization