OBEA is a tool to help produce formative assessment tasks in Outcomes Based Education (OBE). It has been developed for use with the OBE Système implemented by the Curriculum Council of the Western Australian government. The main idea with OBEA is to assign numerical marks to questions and be able to determine the conceptual level of achievement (level/band) for that task using these marks. Why use OBEA? Using OBEA produces valid student results that are explicit and comparable between students within schools and students between schools. Teachers will find that OBEA will reduce the subjectivity in determining a level of achievement for an assessment. Other benefits to assessing using OBEA include:- Ability to average results for a particular student, class or year group - Rank students to determine end of year prize winners- Ranks students so that they can be streamed- Reduce teacher marking time considerably- Minimize subjectivity