Purpose: To improve understanding of how nurses define or redefine medication error.
Design: Qualitative descriptive.
Methods: This 18-week ethnomethodological study in one hospital used participant observation, documentary analysis, and validation criteria. Ethnomethodology is useful for making clearer the every-day, taken-for-granted understandings and practices of people as they make sense of their world. It hinges on the use of tacitly held knowledge in practical situations.
Findings: Nurses adopted practices and embodied logic to accomplish tasks. They created criteria to decide when incidents were "real errors" and used institutional rules to create order.
Conclusions: The findings provide a body of tacitly held knowledge about medication error that is shared among clinical nurses and redefines medication error using six criteria. The study calls into question the way institutions seek to identify, document, and reduce medication errors by nurses and the validity of nursing research based on reported error rates.