The purpose of this study was to introduce the development of a computerized tool, called ‘MedObs Collector’ and its' qualitative usefulness in a medication error study. The requirements for a tool were driven from the medication error research design and users of five research assistants. The MedObs Collector was designed to support multi-user data input and automatic match between data records. MS Access® was used in implementation. We applied this tool to collecting and managing data in a clinical setting and received feedback from users. Through the informal evaluation we found several advantages in training and establishing reliability. It has also reduced the amount of time required for data entry.