Psychoanalytic understanding depends on interpretations of evidence from speech and behaviors within clinical encounters. A clinician's particular theoretical perspective orients them to favor one interpretation over another. Yet, this continuous processing of evidence often proceeds without a careful examination of the underlying basic concept: the representation being interpreted. This essay is an application of Charles Sanders Peirce's theory of semiosis, which articulates types of representation and their implications for interpretation. A more nuanced understanding of aspects of representation and their use for specific purposes could generate greater consensus in psychoanalytic interpretations and their uses for clinical diagnosis or treatment—as Freud originally envisioned but lacked a semiotic theory to describe.