This article focuses on interpreting theories when they are functioning in an ongoing investigation. The sustained search for a quark-gluon plasma serves as a prime example. The analysis treats the Standard Model of Particle Physics as an Effective Field Theory. Related effective theories functioning in different energy ranges can have different functional ontologies, or models of the reality treated. A functional ontology supplies a categorial framework that grounds and limits the language used in describing experiments and reporting results. The scope and limitations of such a local functional realism are evaluated.