The occupations that they gave in their answers were later classified in the 2008 International Standard Classification of Occupations (ISCO 08). These coded answers were used to create an indicator of science-related career expectations, defined as those whose realisation requires the study of science beyond compulsory education, typically in formal tertiary education. Within this large group of science-related occupations, the following major groups were distinguished: science and engineering professionals, health professionals, science technicians and associate professionals, and information and communication technology (ICT) professionals.