Described is the use of query identifiers that provide computer users a method of "bookmarking" (uniquely identifying) any user interface (UI) element in any UI framework. This is useful for testing programs, assistive technologies, and teaching activities. The unique query element identifier is identified for a target UI element to locate within a hierarchy of UI elements. For example, the element's Name, ClassName, Instance, AccessibleName, Role, ControlId and AutomationId may be used to develop the unique query element identifier. From the query elements in the hierarchy of UI elements, a query identifier is generated for the target UI element. The query identifier includes the query element identifier and possibly ancestor query element identifiers, with each ancestor query element identifier corresponding to a higher-level ancestor element relative to the target element in the hierarchy. The query identifier may be used to locate the target element for testing versions of application programs.