This article describes current awarding practice and reviews literature about writing and using grade descriptors for GCSEs and A levels. Grade descriptors are descriptions of the qualities anticipated at various levels of a candidates’ performance in an assessment. It is concluded that it is good practice to write grade descriptors based on empirical evidence. Grade descriptors for different domains and types of questions can be written by:

1. identifying questions where there is a statistically significant difference between the performance of students who achieve adjacent grades (e.g. A and B);
2. using Kelly's Repertory Grid to interview examiners about the qualities which distinguish performance at these grades;
3. including these distinguishing qualities in grade descriptors.

Furthermore, there is little research about how grade descriptors are used, or could be used, in preparing pupils for assessments, and there is room for further research in this area.