The design principles of
ISCO-08:
Challenges for coding occupations
globally
David Hunter, Department of Statistics
International Labour Office
InGRID Expert Workshop
New skills for new jobs: Tools for harmonising the measurement
of occupations
AIAS Amsterdam, 10 -12 February 2014
The design principles of ISCO-08: Challenges for coding occupations
globally
International Standard Classification of
Occupations 2008 (ISCO-08)
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•
•
Endorsed by the ILO Governing Body in 2008 it is known as ISCO-08 and
replaces ISCO-88
Structure, group definitions and correspondence with ISCO-88 available on
ILO Website or on request
Published in English
– And in French, Spanish, Arabic and Russian as soon as possible
•
•
•
Index of occupational titles will be available very soon
Used in European Union (EU) collections from 2010
Structure is available in all EU languages from Eurostat
–
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Eurostat Web discussion forum to support implementation is available to all countries
Hierarchically structured classification comprising:
– 10 major groups
– 43 sub-major groups
– 130 minor groups
– 436 unit groups
The design principles of ISCO-08: Challenges for coding occupations globally
What is ISCO used for?
 International reporting, comparison and exchange of
statistical and administrative data on occupation
 A model for the development of national and regional
classifications of occupations
 Used directly in countries that have not developed their
own national classifications
The design principles of ISCO-08: Challenges for coding occupations globally
Uses of occupation classifications
Statistics from censuses, household surveys, employer surveys
and other sources (big data?).
• Detailed observations about jobs are organized into meaningful and useful
groups for analysis
Administrative and policy-related activities
• matching job seekers with job vacancies
• educational planning
• management of employment related international migration
Providing statistics on
•
•
•
•
job seekers and job vacancies
numbers of places and enrolments in training programmes
Migrant and expatriate labour
Employment numbers, wages, hours worked etc.
The design principles of ISCO-08: Challenges for coding occupations globally
Underlying concepts –ISCO-08
• Job : a set of tasks and duties performed, or meant to be
performed, by one person including for an employer or in self
employment.
• Occupation: a set of jobs whose main tasks and duties are
characterised by a high degree of similarity:
– A person may be associated with an occupation through the main job
currently held, a second job, or a job previously held
• Occupations are organized into groups according to skill level and
skill specialization:
– Skill level is applied mainly at the top (major group) level of the
classification.
– Within each major group occupations are arranged into unit groups,
minor groups and sub-major groups, primarily on the basis of aspects of
skill specialization.
The design principles of ISCO-08: Challenges for coding occupations globally
Skill – the ability to carry out the
tasks and duties of a job
Skill level: the complexity and range of tasks and duties performed in
an occupation:
– Measured operationally by considering:
 The nature of the work performed in an occupation in relation to the
characteristic tasks and duties defined for each ISCO-08 skill level
(new for ISCO-08)
And/or
 The level of formal education
 The amount of informal on-the-job training and/or previous
experience in a related occupation
required for competent performance of the tasks and duties
Skill specialization
 the field of knowledge required
 the tools and machinery used
 the materials worked on or with
 the kinds of goods and services produced.
The design principles of ISCO-08: Challenges for coding occupations globally
Table 1: Mapping of ISCO-08 major
groups to skill levels
ISCO-08 major groups
1 - Managers
Skill Level
3+4
2 - Professionals
4
3 - Technicians and associate professionals
3
4 - Clerical support workers
5 - Service and sales workers
6 - Skilled agricultural and fishery workers
7 - Craft and related trades workers
8 - Plant and machine operators, and assemblers
2
9 - Elementary occupations
1
0 –Armed forces occupations
The design principles of ISCO-08: Challenges for coding occupations globally
1, 2 + 4
Sub-major groups in Major group 2,
Professionals
ISCO-08
Code
ISCO-08 Title
21
Science and engineering professionals
22
Health professionals
23
Teaching professionals
24
Business and administration professionals
25
Information and communications technology
professionals
Legal, social and cultural professionals
26
The design principles of ISCO-08: Challenges for coding occupations globally
22 Health professionals
221
2211
2212
222
2221
2222
223
2230
224
2240
225
2250
226
2261
2262
2263
2264
2265
2266
2267
2269
Medical doctors
Generalist medical practitioners
Specialist medical practitioners
Nursing and midwifery professionals
Nursing professionals
Midwifery professionals
Traditional and complementary medicine professionals
Traditional and complementary medicine professionals
Paramedical practitioners
Paramedical practitioners
Veterinarians
Veterinarians
Other health professionals
Dentists
Pharmacists
Environmental and occupational health and hygiene professionals
Physiotherapists
Dieticians and nutritionists
Audiologists and speech therapists
Optometrists and ophthalmic opticians
Health professionals not elsewhere classified
The design principles of ISCO-08: Challenges for coding occupations globally
32 Health associate professionals
321
322
323
324
325
Medical and pharmaceutical technicians
3211
Medical imaging and therapeutic equipment technicians
3212
Medical and pathology laboratory technicians
3213
Pharmaceutical technicians and assistants
3214
Medical and dental prosthetic technicians
Nursing and midwifery associate professionals
3221
Nursing associate professionals
3222
Midwifery associate professionals
Traditional and complementary medicine associate professionals
3230
Traditional and complementary medicine associate professionals
Veterinary technicians and assistants
3240
Veterinary technicians and assistants
Other health associate professionals
3251
Dental assistants and therapists
3252
Medical records and health information technicians
3253
Community health workers
3254
Dispensing opticians
3255
Physiotherapy technicians and assistants
3256
Medical assistants
3257
Environmental and occupational health inspectors and associates
3258
Ambulance workers
3259
Health associate professionals not elsewhere classified
The design principles of ISCO-08: Challenges for coding occupations globally
Models for developing or adapting national
classifications based on ISCO
• Adopt ISCO directly for national use
– Much less than ideal
– Some small countries with limited resources have no other choice
– Collaborating with similar neighbouring countries may be an option
• Adapt ISCO to suit national circumstances
– A popular choice
– May start from scratch
– One or more classifications may already be used in the country
• National occupation classification is not based on ISCO
– A common situation for countries with own tradition or history of
occupation classification
– May make adjustments to national classification to improve
comparability with ISCO or take advantages of new features in ISCO
The design principles of ISCO-08: Challenges for coding occupations globally
Adapting ISCO to suit national circumstances:
starting from scratch or from an existing national
classification
• Decide at what level of ISCO-08 you will provide internationally
comparable data (Eg 3 or 4 digits)
• Collapse ISCO categories that are too detailed for national requirements
– Eg by making a minor group into a unit group.
• Create more detailed categories where needed to suit national labour
market, user requirements:
– For example by adapting the 4th level or creating a 5th level
• Adjust the classification code structure as needed while maintaining
correspondence table with ISCO-08 and old classification
• Develop or update national index of occupation titles containing
new and old national and ISCO codes (2, 3 or 4 code sets may be
needed)
• Develop definitions of new or changed categories
• Review and amend ISCO-08 definitions to ensure national relevance
– Eg lists of included occupations
The design principles of ISCO-08: Challenges for coding occupations globally
Occupation – information needed for
coding
• For accurate coding to any level of ISCO (and related
national classifications) information is needed on:
– Name or title of occupation
– Main tasks or duties usually performed in the job
• The following may information may also be useful
– The type of economic activity of the establishment (industry)
– Whether or not the main aim of the activity is own consumption
(subsistence)
• Information about the level of skill or qualifications of an
individual is not necessary and not useful
The design principles of ISCO-08: Challenges for coding occupations globally
Occupation – single open-ended
questions
• A single question such as:
a) What is the main occupation of (the person) in this workplace?
b) What kind of work did (the person) do?
may provide adequate information from some but not all
respondents
–
But may yield responses such as ‘Manager’, ‘Consultant’,
‘Farm work’ that can not be coded accurately to any level of
ISCO
• Interviewers need to be trained to probe when
information provided is insufficient
The design principles of ISCO-08: Challenges for coding occupations globally
Occupation – multiple openended questions
• Use of separate questions on job title and tasks
performed generally assures that sufficient detail
is provided
• Asking for two different types of information
helps the respondent to respond fully, for
example:
Title: Sales manager
Tasks: Selling used cars
Title: Customer service consultant
Tasks: Selling used cars
The design principles of ISCO-08: Challenges for coding occupations
globally
Questions recommended for testing and
adaptation at national level
In the main job held last week what was your work or occupation?
Please give full job title and be specific, for example:
Fruit picker, Legal secretary, Restaurant manager, Secondary school teacher,
Cattle farmer, Registered nurse
…………………………………………………………………………………
………………………………………………………………………
What are your main tasks or duties in that job?
Please give details, for example:
Picking and carrying oranges and peaches, Preparing legal documents, Managing
the operations of a restaurant, Teaching mathematics, Managing a cattle farm,
Caring for the sick and administering medications
…………………………………………………………………………………
………………………………………………………………………………
………………………………………………………………………………
……
The design principles of ISCO-08: Challenges for coding occupations
globally
Coding occupational data in
household surveys
• Responses to open ended questions have to be assigned
to the appropriate category in an occupation classification
• Responses to questions on occupation (title and tasks),
industry and name and address of workplace are relevant
• Coding should be done using and index of occupations
– Mapping directly to the classification is error prone and inefficient
• Aim of the coding process is to determine and record
correctly to which of the categories in the occupation
classification the jobs belong
• at the most detailed level possible on the basis of the
information provided in the responses
The design principles of ISCO-08: Challenges for coding occupations globally
Sources of information for constructing and
updating an occupation coding index
– Reviews of responses from recent survey operations and census
tests
– Job vacancy reviews (newspapers, internet, employment
services)
– Full-scale job monitoring exercises
– ISCO index may be a good starting point in the absence of any
national index or a useful source to assess completeness of a
national index
– Do neighbouring countries with similar languages have indexes
that could be shared or adapted?
– Index needs to reflect language used in the national context in
response to questions in statistical collections and administrative
forms
The design principles of ISCO-08: Challenges for coding occupations globally
At what level of the classification should
responses be coded?
• It is sometimes decided to code to an aggregate level of ISCO (Eg 2
or 3-digit level of ISCO)
– Perceived cost of coding in terms of errors and staff hours
– Concern that responses may not be codable to detailed groups
– In sample surveys the detailed results may not be publishable
BUT
– Information is unnecessarily lost
– limits options for tabulation, international reporting
Experience of statistical agencies has shown that
– Costs of coding to a larger number of categories are small
– Error rates do not significantly increase and may improve for
aggregate groups
– Many responses support detailed coding, while some do not
The design principles of ISCO-08: Challenges for coding occupations globally
Coding of vague and difficult
responses
Some responses may be too vague and imprecise to allow
the coder to determine to which category the job belongs
– These responses should be coded to the level in the classification
structure supported by the information contained in them
– should not be forced into any particular detailed category where only a
small proportion of the jobs would fall if the responses were adequate.
– Residual groups (not elsewhere classified) should not be used for vague
responses
– A common method of dealing with this type of response is to provide
entries in the coding index for commonly occurring vague responses
– Such responses are assigned the code for the relevant higher category,
followed by trailing zeros.
• responses can be allocated proportionally to the more detailed
categories in a transparent manner
• or they can be released in publications labelled as : ‘Group name
not further defined’
The design principles of ISCO-08: Challenges for coding occupations globally
Occupation title: Sales
Tasks performed: Selling
52 Sales workers
5200 Sales workers not further defined
521 Street and market salespersons
5211 Stall and market salespersons
5212 Street food salespersons
522 Shop salespersons
5221 Shopkeepers
5222 Shop supervisors
5223 Shop sales assistants
523 Cashiers and ticket clerks
5230 Cashiers and ticket clerks
524 Other sales workers
5241 Fashion and other models
5242 Sales demonstrators
5243 Door to door salespersons
5244 Contact centre salespersons
5245 Service station attendants
5246 Food service counter attendants
5249 Sales workers not elsewhere classified
The design principles of ISCO-08: Challenges for coding occupations globally
Automatic and computer assisted
coding
• Both approaches use computing power to speed up process of
searching an index, identifying matching responses, following
coding rules and recording the correct code
• In Computer assisted coding (CAC) the coder enters a small number
of characters from key and qualifying words
– Matching index entries are displayed and coder selects matching entry
– Correct code is recorded by coder or the computer or a query is raised
• In automatic coding (AC) responses are key entered or captured
electronically, then matched automatically by the computer
– Match rates of up to 70% have been achieved
– Remaining entries are coded using CAC
– Requires a high degree of sophistication and a very well designed index
• Software solutions are available at low cost but cost of integration
into larger processing systems may be high
The design principles of ISCO-08: Challenges for coding occupations
globally
Summary – challenges for achieving
globally comparable occupational data
• Different countries use different classification systems, based (or not) on
different versions of ISCO
• Within countries different classification systems may be used for
different applications
– ‘Big data’ may make this worse while making more information available
• Varying quality of occupational information collected on statistical and
administrative forms
• Multiple approaches to coding occupational data (index and procedures)
• Difficulty in achieving international consistency due to linguistic
differences
• Technological solutions (CAC, AC, OCR) can improve consistency
– May lead to systematic error if badly implemented
– Difficult for less developed countries to use
• Need for coordination and leadership from national statistical offices and
international institutions
The design principles of ISCO-08: Challenges for coding occupations globally