Diarrhea is a condition in which a person defecates in a runny or liquid form and occurs repeatedly. Diarrhea can cause the loss of large amounts of water and substances needed by the body. Diarrhea is one of the health problems in developing countries, especially in Indonesia both in urban and rural areas. Diarrhea morbidity rates around 200-400 occurrences among 1000 residents each year. Thus in Indonesia there can be around 60 million incidents each year, most (70-80%) of these sufferers are children under five years (BALITA). Some patients (1- 2%) will fall into dehydration and if not immediately helped 50-60% of them can die. This group experiences more than one incidence of diarrhea every year. K-Medoids Algorithm Clustering is one of the algorithms used for to group data.Keywords: Data Mining, K-Medoids, Clustering, Diarrhea

The existence of new students at a tertiary institution is a routine activity every year in a tertiary institution and can also see the sustainability of the tertiary institution. The variety of regional origin of new students makes the party from the university want to see the distribution of new students based on the origin of the school and its place of residence. STIKOM Tunas Bangsa is one of the tertiary institutions in Pematangsiantar. It aims to promote the university. K-Medoids is able to group data on the distribution of new students in STIKOM Tunas Bangsa Pematangsiantar. The clusters produced in this study are of three clusters. The validity used in this study is the validity of Silhoutte Coefficient. The validity value generated in the K-Medoids algorithm produces a validity value of -116.47 by assuming that if the non-medoids value produced S