Definition: International Standard Classification of Occupations
The framework necessary for designing and constructing ISCO-88 has been based on two main concepts: the concept of the kind of work performed or "job", and the concept of "skill". "Job" - defined as a set of tasks and duties executed, or meant to be executed, by one person - is the statistical unit classified by ISCO-88. A set of jobs whose main tasks and duties are characterised by a high degree of similarity constitutes an occupation. Persons are classified by occupation through their relationship to a past, present or future job. "Skill" - defined as the ability to carry out the tasks and duties of a given job - has, for the purposes of ISCO-88, two dimensions: 1) "Skill level" - which is a function of the complexity and range of the tasks and duties involved, and 2) "Skill specialisation" - defined by the field of knowledge required, the tools and machinery used, the materials worked on or with, as well as the kinds of goods and services produced.
ISCO-88(COM) is the European Union variant of the International Standard Classification of Occupations. ISCO-88(COM) should not be regarded as a different classification from ISCO-88, but rather it is the result of a coordinated effort to implement ISCO-88 for census and survey coding purposes.
Introduction to ISCO-88, and Eurostat