The popularity of design thinking as an innovation paradigm grows continuously. More and more schools and firms implement innovation processes inspired by design thinking, but they lack easy and nonintrusive methods for monitoring the progress of teams following those processes. Consequently, interventions from coaches, teachers, or supervisors tend to rely on intuition or require intensive and intrusive examination of team dynamics. This study uses by-products from the design process and proposes automated assessment of lexical diversity as a monitoring method in process-driven design thinking projects. Thereby, it contributes to the research on the relation between text production and creativity in design projects. To the practical end, it suggests how digitalized by-products of design activities such as notes and documentation, can be leveraged to support the teams as well as coaches, teachers, and supervisors.