The mathematical perspective

Association rule learning assumes that you have a transactional database to learn from. This doesn't refer to any specific technology, but rather the concept of a database that stores transactions—the database can be an array in memory, an Excel file, or a table in your production MySQL or PostgreSQL instance. Since association rule learning was developed for products in supermarkets, the original transactional database was a list of items bought by each individual shopper on a given shopping trip—essentially an archive of receipts from the checkout aisle. However, a transactional database can be any list of items or events that occur during a single session, whether that session is a shopping trip, a website visit, or a trip to a doctor. For the time being, we'll consider the supermarket example. We'll discuss other uses...