The Gender Equity in Senior Secondary School Assessment (ESSSA) Project has been funded by the Department of Employment, Education and Training as a Project of National Significance to explore assessment issues in the post- compulsory area, with a particular focus on gender equity in the performance outcomes of students. This is the largest project of its kind and the first awarded to an assessment authority. The Project is managed by the Senior Secondary Assessment Board of South Australia (SSABSA) on behalf of all of the Australian Curriculum, Assessment and Certification Authorities (ACACA), and is designed to fill an identified gap in national research in the assessment area. The involvement of all Australian assessment authorities in the Project indicates their commitment both to ensuring that the assessment instruments they use are equitable, and to the monitoring of student performance in relation to these instruments. A significant amount of research work into assessment has already been undertaken at the state level by many of the assessment authorities. The work of the ESSSA Project is both drawing on and supplementing this, by producing national participation and performance statistics in selected subjects, and exploring differential outcomes by gender in relation to question type and nature.