In this paper, we proposed a hybrid algorithm using topdown
(Bisect K-means) and bottom-up (UPGMA) agglomerative
hierarchical clustering algorithm called hybrid bisect
K-means. We compared the clusters generated by the hybrid
bisect K-means algorithm with the clusters generated by the
bisect K-means algorithm based on the three evaluation metrics:
Entropy, F-Measure, and Purity of the clusters. Based
on the results obtained, we found that the hybrid bisect Kmeans
algorithm outperforms the bisect K-means algorithm
and produces better clusters. We have also shown that our
algorithm produces better clusters with time complexity of
O(N), which is better than the O(N2) time complexity of
UPGMA algorithm.