Thesis (BS Applied Mathematics) -- University of the Philippines Mindanao, 2011

This study evaluates an existing index of commonness, the kf-score method, and reformulate it with respect to the gaps that it exhibited. The reformulation commonness index was based on the reverse method of measuring diversity. The performance of the reformulated commonness index was compared to the results of the kf-score method, the method that it was derived from, and the Gini-Simpson diversity index, the index that it was based on. The comparison was done by comparing the results of the 3 methods using descriptive statistics and by Kruskal-Wallis non-parametric comparison test. The results of the reformulated commonness index was seen to be better than the results of the 2 other methods. When compared statistically by Kruskal-Wallis non-parametric comparison test, one or more of the methods were proven to have significantly different result. Therefore, the methods were further compared using the Dunn's post-test, the formulated commonness index and the kf-score method were proven to be statistically different.. However, the formulated commonness index and the Gin-Simpson diversity index resulted to have no significant difference at all. Therefore, it was concluded that both methods, the formulated index and the Gini-Simpson diversity index, can be good measures of commonness, though the formulated commonness index generates a more elegant set commonness scores. This is because the formulated commonness index gives results that are more or less distinct from other commonness scores.