SQL: Combining tables without JOIN

SQL is a versatile language--there are many ways to get the job done. One way to compare information from multiple tables is the JOIN command, but there are sometimes alternatives. Let's say I've got two tables, office and person: Let's say I need to know which people have printers. I could do a JOIN ON office_room = office_num.…

Information Criteria & Cross Validation

A problem of predictive models is overfitting. This happens when the model is too responsive and picks up trends that are due to quirks in a specific sample, and not reflective of general, underlying trends in the data process. The result is a model that doesn't predict very well. A model can be made less responsive by regularization--i.e.…