Academic papers submitted to a conference are assessed by reviewers and judged if they deserve to be presented at the conference. The accepted papers are often classified into full papers, short papers, and other types, according mainly to the reviewers' assessment. The major aim of the study presented in this paper is to find tips which are effective for a paper to be improved so that a paper supposed to be classified as a short paper becomes a full paper. In this study, we investigate a scenario for finding the differences between full and short papers on the usage of words/terms. Then, we extract words which are characteristic for either full or short papers through an experimental study. In order to find these words, we introduce a couple of indexes of a word. The results inspire that we can obtain practical tips in this approach by refining this method.