After marks are awarded for all five assessment criteria, they are converted into letter grades using 'grade boundaries'. Grade boundaries are not subject specific. In theory these boundaries can change from year to year. In practice they usually stay the same. The following boundaries can be applied to sample Extended Essays. They can also be used as a tool to determine a candidate's 'predicted grade'. Please note, however, that the 'official' boundaries are not published by the IB until after each exam session.