Your definition of usefulness fails to include the utility of the predictions made, which is the most important factor. A theory is useful if there is a chain of inference from it to a concrete application, and its degree of usefulness depends on the utility of that application, whether it could have been reached without using the theory, and the resources required to follow that chain of inference. Measuring usefulness requires entangling theories with applications and decisions, whereas truthfulness does not. Consequently, it’s incorrect to treat truthfulness as a special case of usefulness or vise versa.
Measuring usefulness requires entangling theories with applications and decisions, whereas truthfulness does not. Consequently, it’s incorrect to treat truthfulness as a special case of usefulness or vise versa.
From pwno:
“Aren’t true theories defined by how useful they are in some application?”
My definition of “usefulness” was built with the express purpose of relating the truth of theories to how useful they are and is very much a context specific temporary definition (hence “define:”). If I had tried to deal with it directly I would have had something uselessly messy and incomplete, or I could have used a true but also uninformative expectation approach and hid all of the complexity. Instead, I experimented and tried to force the concepts to unify in some way. To do so I stretched the definition of usefulness pretty much to the breaking point and omitted any direct relation to utility functions. I found it a useful thought to think and hope you do as well even if you take issue with my use of the name “usefulness”.
Your definition of usefulness fails to include the utility of the predictions made, which is the most important factor. A theory is useful if there is a chain of inference from it to a concrete application, and its degree of usefulness depends on the utility of that application, whether it could have been reached without using the theory, and the resources required to follow that chain of inference. Measuring usefulness requires entangling theories with applications and decisions, whereas truthfulness does not. Consequently, it’s incorrect to treat truthfulness as a special case of usefulness or vise versa.
Thank you—that’s an excellent summary.
From pwno: “Aren’t true theories defined by how useful they are in some application?”
My definition of “usefulness” was built with the express purpose of relating the truth of theories to how useful they are and is very much a context specific temporary definition (hence “define:”). If I had tried to deal with it directly I would have had something uselessly messy and incomplete, or I could have used a true but also uninformative expectation approach and hid all of the complexity. Instead, I experimented and tried to force the concepts to unify in some way. To do so I stretched the definition of usefulness pretty much to the breaking point and omitted any direct relation to utility functions. I found it a useful thought to think and hope you do as well even if you take issue with my use of the name “usefulness”.