Model-driven coding with VPAT: The Verbal Protocol Analysis Tool

We present the coding tool VPAT (Verbal Protocol Analysis Tool), specifically designed to facilitate model driven analysis of users' verbal data. Such model-driven coding presents challenges in terms of efficiency and reliability. Engineers and researchers need effective means of coding with complex, hierarchical, multi-level coding schemes. VPAT allows input of customizable coding schemes, quick and easy insertion of codes into text documents with a user-friendly interface, and extraction of codes for analysis purposes. VPAT was developed for research purposes with user-centered design methods with various stakeholders. The VPAT prototype runs in conjunction with MS Access and MS Excel. Comparative task analysis breakdowns of main coding tasks in VPAT and a leading coding application are presented to demonstrate advantages and tradeoffs. A case study of coding usability data for a healthcare information retrieval system is presented to demonstrate usage and benefits. VPAT is a specific tool suited to model-based coding, and was shown to increase speed and reliability.