This thesis presents the development, implementation, and evaluation of BaLex, a Technology-Assisted Vocabulary Learning (TAVL) tool designed for university-level language courses. Employing a Design-Based Research (DBR) approach, the study integrates theoretical principles of vocabulary acquisition with practical considerations of technology integration in educational settings.

The research began with a comprehensive literature review, identifying gaps in existing TAVL tools, particularly in supporting collaborative learning and integrating teacher guidance. User requirements were gathered through surveys and interviews with students and teachers, highlighting the need for flexible, engaging tools that support both autonomous and guided learning.

BaLex was developed as a digital collaborative vocabulary notebook, incorporating features such as comprehensive lexical entries, collaborative editing, and gamification elements. The tool’s design was informed by established vocabulary learning theories and user feedback, aiming to bridge the gap between classroom instruction and independent learning.

Two implementation studies were conducted: the first at Universit. Lyon 2 in France, and the second at Carnegie Mellon University in the United States. These studies revealed insights into tool adoption, user engagement, and the impact on vocabulary learning. While overall results showed positive effects on vocabulary acquisition and user motivation, they also highlighted challenges in sustained engagement and integration into existing teaching practices.

The thesis contributes to the field by providing empirical data on the effectiveness of collaborative TAVL tools, offering insights into the design and implementation of such tools, and proposing refinements to existing models of technologyassisted language learning. It also addresses broader implications for educational technology integration in higher education.

This research not only advances our understanding of effective vocabulary learning strategies in technology-enhanced environments but also provides practical insights for the development and implementation of TAVL tools in diverse educational contexts.