Degree of similarity in the vocabulary between verbal data

The present paper discusses how to measure the degree of similarity or difference in the vocabulary between the two language data, and proposes a new measure of vocabulary similarity, which is defined as … where pi (X) and pi (Y) are the rates of occurrence of the i th vocabulary type (or word type) in the two laguage data. Since S is the sum of si which is defined as : … si can be regarded as a measure showing how much a given vocabulary type contributes to the overall similarity or dissimilarity of the two language data. It is also shown how S and si are applied to the analysis of a set of actual data, taking hibakusha's memoirs of the A-bomb experiences as example