Specificity

The purpose of Specificity is actually to make assertions more discoverable and extensible. Most assertion APIs use static methods, segmented on multiple static classes based on the type of object you'll be making the assertion on.

A generic Assert class holds assertions for Object types. A StringAssert holds assertions for String types. A CollectionAssert holds assertions for ICollection types. While reasonable in the .NET 2.0 era, this approach isn't overly discoverable.