Underdetermination

This article includes a list of general references, but it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. (March 2016) (Learn how and when to remove this message)

In the philosophy of science, underdetermination or the underdetermination of theory by data (sometimes abbreviated UTD) is the idea that evidence available to us at a given time may be insufficient to determine what beliefs we should hold in response to it.^[1] The underdetermination thesis says that all evidence necessarily underdetermines any scientific theory.^[2]

Underdetermination exists when available evidence is insufficient to identify which belief one should hold about that evidence. For example, if all that was known was that exactly $10 were spent on apples and oranges, and that apples cost $1 and oranges $2, then one would know enough to eliminate some possibilities (e.g., 6 oranges could not have been purchased), but one would not have enough evidence to know which specific combination of apples and oranges were purchased. In this example, one would say that belief in what combination was purchased is underdetermined by the available evidence.

In contrast, overdetermination in philosophy of science means that more evidence is available than is necessary to justify a conclusion.