1) A process in which learners/ trainees / students collects evidences about themselves, judge and assess their own performance against particular competency standards and criteria; 2) A process in which an enterprise or training provider assesses the extent to which it satisfies the criteria for quality endorsement of the training provider’s learning, education and training system and identifies opportunities for improvement. (Similar definition used by Queensland government)
Source: Wahba 2013, Global

Assessment by which the learner gathers information about and reflects on his or her own learning, judges the degree to which it reflects explicitly stated goals or criteria, identifies strengths and weaknesses, and revises accordingly. It is the learner’s own assessment of personal progress in knowledge, skills, processes, and attitudes. (Adapted from: Ontario Ministry of Education 2002).
Source: UNESCO IBE 2013, Global