The signing of the Bologna Agreement in 1999 has major implications for all involved in third level education throughout the world. By 2010 in the 45 countries that have signed up to the Bologna process, all modules and programmes in third level institutions will be written in terms of learning outcomes. In addition, many countries outside the Bologna process are aligning their third-level educational systems to be compatible with the Bologna process in order to facilitate description of qualifications, mutual recognition of degrees, and mobility of students. This paper covers the background to the concept of Learning Outcomes, the use of Bloom's Taxonomy to write learning outcomes, the relationship between learning outcomes and competences, and the linking of learning outcomes to both teaching and learning activities as well as to assessment. In addition, the author discusses the effects of the introduction of learning outcomes into the teacher-training programme for science teachers in his own university with particular reference to the assessment of student learning. (Contains 2 figures and 4 tables.)