The ILO provides member states and other users with useful tools and resources for using ISCO.

Assisted ISCO Coding and search functions

These features will be soon available

This program is developed by the Department of Statistics of the ILO to assist the online coding of text information on occupation to ISCO in a quick and easy way. The program supports a multilingual version of ISCO-08 and ISCO-88; it is available in English, French and Spanish. The Arabic version of the program will be soon available only for ISCO-08. The program is free of charge. The current version of the program is v.1.0

How does the program work?

The program aims at helping users to find the most appropriate code and title of an occupation within ISCO. It is based on ISCO hierarchical structure. By answering questions, the model will help users to subsequently navigate between the different ISCO groups, starting with Major Groups or 1-digit until the most appropriate Unit Group or 4-digit occupational code or title is identified and selected. The program also has an integrated search function that allows you to quickly find a code or occupational title in ISCO. A step-by-step guide to use the program can be downloaded here.

ISCO-08 In my language

These features will be soon available

ISCO-08 in French

You can also visit the ISCO page in French

ISCO-08 in Spanish

You can also visit the ISCO page in Spanish

ISCO-08 in Arabic

ISCO-08 will be soon available in Arabic.

Key concepts concerning a statistical classification of occupations

What is an occupational classification?

An occupational classification is a tool for organising all jobs into a clearly defined set of groups according to the tasks and duties undertaken in the job. It normally consists of two components:

  • The classification system itself, which gives the guidelines on how jobs are to be classified into the most detailed groups of the classification and how these detailed groups are to be further aggregated into broader groups. It includes the occupational titles and codes, and represents a value set for the variable occupation, a variable which describes the different tasks and duties of jobs.
  • A descriptive component, which usually consists of descriptions of the tasks and duties as well as other aspects of the jobs which belong to each of the defined groups, including goods and services produced, skill level and specialization, occupations included and excluded, entry restrictions, etc. These descriptions can be said to constitute a dictionary of occupations.

What are the basic principles of an occupational classification?

Any classification of occupations is based on principles for: classification unit(s), classification variable(s) and similarity criteria.

  • Classification unit(s) : Occupational classifications generally classify jobs. Jobs can be: past, present or future jobs; paid employment jobs; self-employment jobs; jobs without incumbents (vacancies); etc. (For definitions and concepts related to employment, you can visit the International Conference of Labour Statisticians (ICLS)). Jobs which have the same set of main tasks and duties are aggregated (grouped together) into occupations. Occupations are grouped together into narrowly or broadly defined occupational groups on the basis of similarity in the type of work done, i.e. similarity in the tasks and duties performed. The units described in a dictionary of occupations are occupations and occupational groups.
  • The classification variable(s) The classification variable in an occupational classification is usually the type of work done, or the tasks and duties performed.
  • The similarity criteria
    The similarity criteria determine the conceptual framework for the composition and location of categories and provide guidance on how to classify new or omitted occupations, how to establish similarity in the main attribute, and how to organize the occupations in the classification. They must relate to known attributes of an occupation and must be clearly and consistently defined and measured according to agreed methodology. Ideally, they should be determined by the use that will be and given to the classification. Thus, to be useful for job placement, human resource budgeting, education planning, skill should be the best criterion; but if the classification is to be useful for the analysis of social stratification or mobility, then occupational prestige would be a more suitable criterion.

Using occupational classifications

What are occupational classifications used for?

National occupational classifications and dictionaries are usually designed to serve several purposes. Although the detailed occupational descriptions and the classification structure must be seen as two parts of an integrated whole, different users have different degrees of interest in the various elements:

  • Detailed occupational descriptions are used by those who need to know about the tasks, duties and working conditions of jobs. They are mostly client oriented users (for example, those responsible for job placement, vocational training and guidance, migration control, etc.). The occupational descriptions should be designed primarily to meet the needs of such users, but must also include the descriptive elements necessary for applying relevant aggregation schemes.
  • The classification structure, i.e. the grouping of the detailed occupations together in progressively more aggregate groups, should be designed mainly to facilitate the sorting of jobs and persons into groups, i.e. for the matching of job seekers and vacancies, or for statistical description and analysis of the labour market and the social and economic structure of society.

Depending on the purpose of the study, the variable occupation may be regarded as the main variable in the empirical analysis, or it may serve as a background variable. Used as a background variable, it may serve as a proxy for other variables such as socio economic groups or working conditions, or it may be used as one element in the construction of other variables, such as social class or socioeconomic status.

Who are the main users of occupational statistics?

User Use of ISCO
Statistical services Sort/classify jobs and persons into occupations to produce statistics on the occupational distribution of employed and unemployed persons, wages, working conditions, occupational injuries, etc. and statistics on the employed and unemployed persons, wages, working conditions, occupational injuries. etc. of particular occupations
Migration authorities Sort persons to make decisions about work permits or visas
Employment services Sort persons and jobs to match jobs seekers and vacancies
Managers of enterprises/organisations Use occupational statistics to sort jobs and persons to plan and decide on wage and other personnel policies, and monitor working conditions at the enterprise and in the context the industry and relevant labour markets
Vocational counsellors Use occupational information to guide school leavers and job seekers about types of work, training requirements, career prospects, working conditions, etc. of different types of jobs
Vocational training specialists Use occupational information as basis for planning and designing vocational training programmes
Legislators and public sector administrators Use occupational statistics in support of the formulation and implementation of economic and social policies and to monitor progress with respect to their application, including those covering manpower planning and the planning of education and vocational training
Psychologists Study the relationship between occupations and the personalities and interests of workers
Epidemiologists Use occupations in their study of work related differences in morbidity and mortality
Sociologists Use occupations as an important variable in the study of differences in life styles, behaviour and social positions
Economists Use occupation in the analysis of differences in the distribution of earnings and incomes over time and between groups, as well as in the analysis of imbalances of supply and demand in different labour markets
The general public Use occupational statistics to analyse, describe and learn about what is happening in their countries

Brief guidelines to develop a statistical classification of occupations

These guidelines are briefly described here, they consist of the following: Development, use, maintenance and revision of the classification.

1. Developing a classification

When developing the classification, the custodian should consider:

Users' requirements:

  • How to determine who the main users are;
  • How to determine what the different users would like the classification to do;

  • How to balance the different users' requirements against each other or make a choice between them when they are contradictory.

    The main conceptual issues, given the users' requirements:

  • What are the (main) variable(s) for which the value-set is valid?

    Example: The variable to which ISCO-08 is applied is "main tasks and duties" of work performed, and not other aspects of work, such as exposure to hazardous substances or uncomfortable working conditions. Thus the variable "occupation" can be said to be defined as "the main tasks and duties of work performed".

  • What are the primary units for which we can measure the main variable(s)?

    Example: "jobs" are the primary units for ISCO-08. A "job" is defined as a set of tasks and duties (designed to be) performed by one person.

  • What are the rules for linking other units to the primary units so that these other units can be assigned values of the classification variable?

    Example: "Persons" can only be assigned an "occupational group" through their link to a past, present or future job. They can only be given an "industry" code by being employed by an establishment.

  • What are the conceptual rules for identifying the same value of the variable?

    Example: For ISCO-08 the rule is "a set of jobs whose main tasks and duties are characterized by a high degree of similarity: they constitute an occupation", which is the most detailed element in the value-set for an occupational classification.

  • What are the similarity criteria used to define higher level categories (aggregated value-sets) in hierarchical classifications?

    Example: In ISCO-08, the main similarity criteria are "skill level" and "skill specialisation" needed to carry out the tasks and duties of jobs.

  • The collection of information: how to collect the information which describes the defined categories and the dividing lines between them?

    Example: for an occupational classification one needs to collect information about the main tasks of jobs in the different occupations for the whole range of work situations that can be found in establishments of different size and in different industries. If one wants to be able to apply different similarity criteria to define alternative aggregated value sets, then all the corresponding information must be collected.

2. Using the classification

Using a classification involves 'Coding of occupations' being the process of attributing the appropriate value of the value-set for a particular unit. The ILO recommends that when coding occupation one should code to the most detailed level in the classification that is supported by the information provided. Title, task etc. should be used according to clearly specified rules. Coding can be conducted by the respondent, by the interviewer or by an expert in coding. It can be manual or assisted.

How to develop appropriate coding tools?

This concerns the development of coding indexes reflecting the type of responses given, as well as with coding rules. The development of automated or assisted coding procedures should reflect the rules to be used for accurate and effective coding.

Quality control procedures

Quality control procedures are needed to monitor the quality of the coding process and to provide feedback both to coders and those responsible for the classification itself and the coding tools.

3. Maintaining the classification

Maintaining a classification involves:

  • The correction of errors made in the construction of the classification (value set) and associated coding tools; and
  • Up-dating of the descriptions of the value-sets, dividing lines between groups and coding tools of the classification when previously unknown or genuinely new types of primary units emerge or are discovered, or as new information is obtained about existing types.

Maintaining a classification should be an ongoing activity of those responsible for the classification, to be combined with training and back-stopping for users of the classification or of the resulting statistics.

4. Revising the classification

Revising a classification involves a review of users' needs as well as the conceptual basis and the users' tools. Such reviews should only be undertaken at long intervals (10-15 years) or if there is compelling evidence that revisions are necessary. The activities involved in revising a classification are essentially the same as those needed to develop it. However, additional methodological issues involved are:

  • How to determine whether a revision is needed.
  • How to determine whether new solutions are better than current practices.
  • How to implement a revised classification in on-going statistical programmes, given the need for comparability with past statistics.

Working papers

Learn more about the International Conference of Labour Statisticians (ICLS)

Reports, documents and other material: https://ilostat.ilo.org/about/standards/icls/