School is an essential context that contributes to children's communicative competence. Decision Support Systems (DSS) are tools that can help teachers to assess their own practice and to make decisions to improve it (Gregg, 2009). Our aim is the construction, implementation and validation of a digital Decision Support System (EVALOE-DSS), conceived as a teacher empowerment tool for self-assessment and decision making about their teaching practice concerning students' oral skills. Participants are 4 teachers and their groups of students of 4 diverse schools. The research procedure includes: 1) design and development of a DSS for different type of schools; 2) researcher assessment of one classroom observation using EVALOE-DSS; 3) weekly teacher self-assessment of classroom observation and decision making using EVALOE-DSS; 4) analysis of self-assessments, decision making and changes in teaching practices; 5) teacher-researcher assessment of the helpfulness of DSS and introduction of changes. EVALOE-DSS is a multimedia tool consisting of 30 items that assess 5 dimensions: teaching management, instructional design, communicative functions and teacher strategies, students' communicative functions, and students' management. It includes, also, a brief description of each item and a variety of resources to help teachers to make decisions and introduce the actions in their teaching practice.