In this article, we are concerned with the processes through which a central activity in the natural sciencesclassificationis instantiated in the writing practices of psychotherapists. We examined several psychotherapists' grammatical, lexical, and rhetorical strategies for writing their initial evaluations of their clients' problems. Using membership categorization device analysis from ethnomethodology, we examined several therapists' written initial evaluations for their use of microlevel categories and categorizations derived both from clients' own (oral) representations and the therapists' professional repertoire. The resulting analysis suggests that clients' emic, contextually grounded expressions are absorbed into a monological account reflecting the therapist' s professional interpretive framework. The therapist thus translates the client' s concerns into a set of meanings compatible with the classifications of psychopathology of the American Psychiatric Association's (1994) Diagnostic and Statistical Manual of Mental Disorders (4th ed.). The resulting written account supports a billable diagnosis thereby fulfilling its institutional purpose. It fails, however, to serve another important purpose to many therapists, which is helping the therapist to guide the therapy process by providing a record of the client's perspective of his or her lifeworld.