This is a derived variable obtained from the educational qualifications questions, which asked for all certificates, diplomas and degrees to be reported. There is an implied hierarchy in this variable (secondary school graduation, registered apprenticeship and trades, college, university) which is loosely tied to the 'in-class' duration of the various types of education. However, at the detailed level a registered apprenticeship graduate may not have completed a secondary school certificate or diploma, nor does an individual with a master's degree necessarily have a certificate or diploma above the bachelor's degree level. Therefore, although the sequence is more or less hierarchical, it is a general rather than an absolute gradient measure of academic achievement.