Abstract: There is provided a grouping system capable of defining groups of customers with similar purchase trends with high accuracy and defining groups of products or product-related items in terms of similar purchase trends, or groups of services or service-related items in terms of similar purchase trends with high accuracy. A purchase trend calculation means 3 calculates a trend of a customer to purchase a product per combination of customer and product or per combination of customer and product-related item as item related to a product on the basis of customers' product purchase situations. A grouping means 4 defines groups of customers and defines groups of products or groups of product-related items on the basis of the trends and a distribution of the trends.

Abstract: Provided is a grouping system capable of determining a group of products so that groups of the products likely to be simultaneously purchased can be grasped. A storage means 71 stores at least a purchasing context that is information indicating one or more types of products purchased in one purchasing activity. A grouping means 72 uses a likelihood of a combination of a group of the purchasing contexts, a group of the products, and a distribution parameter of a purchasing result, calculated by using the purchasing result corresponding to the combination of the group of the purchasing contexts, the group of the products, and the distribution parameter of the purchasing result, to determine the group of the purchasing contexts, the group of the products, and the distribution parameter of the purchasing result.

Abstract: Provided is a grouping system capable of grouping customers and options in each channel, considering variation of behavior of each customer depending on the channel. A grouping means 3 uses a likelihood of a group of customers, a group of options in a first channel, and a group of options in a second channel, calculated based on a distribution parameter of a history of the activity according to a combination of the group of customers and the group of options in the first channel, a history of the activity in the first channel, a distribution parameter of a history of the activity according to a combination of the group of customers and the group of options in the second channel, and a history of the activity in the second channel, to determine the group of customers, the group of options in the first channel, and the group of options in the second channel.