Cases

• Case Based systems are a broad class.
• You need to represent the cases in some kind of data structure. This depends on the problem. The program needs to use the data structure and a similarity metric.
• Typically cases can be decomposed into a series of features.
• The features can be represented in a range of ways, but it's nice to use numbers (integers or floats), and scalars (e.g. colours). Text doesn't usually help much.
• Let's work through an example of bank loans, and whether a bank should grant someone a loan.
• What features are relevant for a bank loan?
• How much the loan is for, how much the person makes, how much they spend, how much they already owe, is the loan secured, how long they want the loan for, the person's name, the person's credit history.
• What about name?
• Let's start with three features, how much the person makes, spends, and how much they'll have to repay each month.
• How are these represented?
• You also need to represent the answer. What's the answer in this case?
• Did they get the loan or not?