You have a group of parameters that naturally go together. ...when you have a bunch of methods that call each other, all of which have a clump of parameters that need this refactoring. In this case you don't want to apply Introduce Parameter Object because it would lead to lots of new objectsThere are times when this transformation yields simpler code, there are times when it makes things more complex, and there are a lot of cases in between where it's a judgment call.