It is interesting to note that 12 of 154 collocations, such as "earn medal" and "block shot" obtained by integrating hierarchies were also obtained by a single hierarchy approach.
other collocations such as "get strikeout" and "make birdie" which were obtained in a particular category (Sport, Baseball) and (Sport, Golf), did not appear in either of the results using a single hierarchy or a non hierarchical approach.