An Analysis of the Efficiency of Existing Kanji Indexes and Development of a Coding-based Index

Considering the problems faced by learners of Japanese from non-kanji background, the present paper discusses the characteristics of 15 existing kanji dictionary indexes. In order to compare the relative efficiency of these indexes, the concept of selectivity is defined, and the selectivity coefficient of the kanji indexes is computed and compared. Furthermore, new indexes developed by the present authors and based on an alphabetical code, a symbol code, a semantic code, and a radical and stroke number code are presented and their use and efficiency are explained.