Traditional software development methodologies enhanced by a clinical component result in information systems that support the practice of nursing. This paper describes the clinical informatics model used to develop and evaluate a mobile computer assessment tool. Data entry of atomic-level elements, with storage in a relational database, allows the synthesis and analysis by multiple disciplines to aid in real-time decision making. The system is designed to improve the recording and accessibility of patient data and nursing observations on a geriatric unit at the Salt Lake VA Medical Center.