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- Concordance between First and Second Editions of the Australian Standard Classification of Occupations (ASCO) - Revised (Jan, 1999) (Feature Article)
Special Article - Concordance between First and Second Editions of the Australian Standard Classification of Occupations (ASCO) - Revised (Jan, 1999)
The following article originally featured in the August 1998 issue of this publication. The table appearing in the article included a number of incorrect figures. The article is reproduced here in full with the corrected table.
(This article is taken from Labour Force Australia January 1999 ABS cat. Number 6203.0).
The Australian Standard Classification of Occupations (ASCO) is published by the ABS and is used in all ABS censuses and surveys where occupation data are collected. The Labour Force Survey (LFS) uses ASCO to classify employed persons to their current occupation, and unemployed persons who previously had a job to the occupation in which they were last employed.
ASCO Second Edition has been used to classify LFS occupation estimates since August 1996. ASCO Second Edition replaced ASCO First Edition which was used to code occupation data in the survey between August 1986 and May 1996. From August 1966 to May 1986, LFS occupation data were coded using the Classification and Classified List of Occupations (CCLO).
The new edition of ASCO was developed following a review of ASCO First Edition undertaken jointly by the Australian Bureau of Statistics (ABS) and the Department of Employment, Education, Training and Youth Affairs (DEETYA), beginning in 1992. In undertaking the review, the ABS and DEETYA consulted key users of occupation data, including industry training bodies, unions, employer bodies and professional associations.
There are a number of important differences between ASCO First Edition and ASCO Second Edition. While the conceptual basis for determining occupations remains unchanged, changes have occurred in the way these concepts are operationalised. In addition, some occupations in the old classification have been deleted and a number of new occupations have been created. The structure of the classification has also changed. As a result of these differences, the old and new editions of ASCO are not directly relateable.
As it is not possible to recode historical data, a consistent time series for LFS occupation data before and after August 1996 does not exist. However, a concordance based on 1996 Census data has been produced to assist users of occupation data to convert ASCO First Edition data to a Second Edition basis. This article provides information about the concordance, and also provides background information about the development and structure of ASCO Second Edition.
THE OCCUPATION CLASSIFICATION
ASCO is a skill based classification of occupations which covers all jobs in the Australian labour force. For the purposes of ASCO, a job is defined as the set of tasks designed to be performed by one individual, while an occupation is a set of jobs with similar sets of tasks. In ASCO, occupations are classified according to skill level and skill specialisation.
In ASCO, the skill level of an occupation is defined as a function of the range and complexity of the set of tasks involved: the greater the range and complexity of the set of tasks, the greater the skill level of the occupation. In ASCO First Edition, skill level was measured operationally as the amount of formal education, on-the-job training and previous experience usually necessary for the satisfactory performance of the set of tasks. The concept of skill level remains unchanged in ASCO Second Edition. However, the operational definition of skill level has been refined as a result of the competency based initiatives in employment and training and an increased emphasis on entry requirements to an occupation. This emphasis on entry requirements arises in part from the difficulty in objectively measuring the skill level required for the satisfactory performance of tasks.
The skill specialisation of an occupation is a function of the field of knowledge required, tools and equipment used, materials worked on, and goods or services provided in relation to the tasks performed.
STRUCTURE OF ASCO SECOND EDITION
ASCO Second Edition has five hierarchical levels: Major Group, Sub-major Group, Minor Group, Unit Group and Occupation. The ‘Sub-major Group’ has been added to enhance options for statistical output. The table below indicates the number of groups in each edition.
In the Labour Force Survey, occupation data will continue to be classified to the Unit Group level.
ASCO Second Edition adopts a more rigorous approach to the application of the skill level criteria than ASCO First Edition, resulting in changes to the way some occupations are classified in ASCO Second Edition. Each of the nine Major Groups in ASCO Second Edition is assigned to one of five skill levels. Major groups at the same skill level are differentiated on the basis of skill specialisation.
Another important change in ASCO Second Edition involves the reorganisation of First Edition Major Groups ‘Clerks’ and ‘Salespersons and Personal Service Workers’, into three Major Groups in Second Edition (broadly defined as Advanced, Intermediate and Elementary). The Second Edition Major Groups better reflect the skill levels of the occupations included in them.
More detailed information about ASCO is available in Information Paper: ASCO - Australian Standard Classification of Occupations (Cat. no.1221.0) and ASCO - Australian Standard Classification of Occupations, Second Edition (Cat. no. 1220.0).
DEVELOPMENT OF ASCO FIRST EDITION TO SECOND EDITION CONCORDANCE
The changes that have occurred between ASCO First Edition and ASCO Second Edition mean that data produced under each classification are not directly relateable. As a result, time series of occupation data are not comparable before and after August 1996.
As it is not possible to recode historical occupation data to the new ASCO, a concordance has been produced which can be applied to historical ASCO First Edition data to convert it to a Second Edition basis. The concordance is designed to provide a matched index of all categories between the old and new versions of ASCO, showing the proportional distributions between the two.
Ideally, a concordance for occupation data for the LFS would be produced by coding a large volume of LFS occupation data to both classifications to produce proportional distributions across matching categories. This, however, would be an expensive exercise. An alternative source of matched ASCO data was available from the 1996 Census (although not released until some time after the Census).
In the processing of Census forms, occupation data from the 1996 Census were coded to both ASCO First and Second Editions. Therefore, a First and Second Edition code was available for each respondent's occupation, which enabled a concordance between the two versions of the classification to be created. An Information Paper published in May 1998 provides detailed information about the link between ASCO First and Second Edition from the Census. For further information, see Information Paper, 1996 Census of Population and Housing, Link between First and Second Editions of Australian Standard Classification of Occupations (Cat. no. 1232.0).
Unlike the LFS which is conducted by trained interviewers, the level of occupation detail provided on Census forms was not always sufficiently detailed to allow coding to the Unit Group level of ASCO (the level used in the LFS). Even though occupation data collected in the Census were generally coded to the ‘Occupation’ (or 6 digit) level, some responses were not adequately described by respondents and so could only be coded to the Major or Sub-major Group (1 or 2 digit) levels.
To enable users of LFS data to convert occupation estimates from a First Edition to Second Edition basis, adjustments were made to allow for missing matches at lower levels of the classification in order to create a true proportional concordance that can be applied to LFS data. Records which did not contain sufficient detail were retained at levels where the amount of detail was acceptable for that level of the classification. At the Major Group level, all valid records were included. However, at finer levels of the classification, the number of contributors decreased as insufficiently detailed records were deleted.
While there are a number of differences in the way occupation data are produced from the Census compared to the LFS (see below) a useable concordance has been produced.
USE OF THE CONCORDANCE
Users of the concordance should be aware of the following limitations:
ASCO First Edition
ASCO Second Edition
- As mentioned above, records containing insufficiently detailed in-formation have been included in the concordance where possible. However, as there are fewer contributors to the concordance at finer levels of the classification, it is less accurate at these levels. This problem has not affected the concordance in a uniform way, resulting in a greater impact on some occupation groups than on others.
- The concordance has been produced using employment information for males and females from the Census. The proportions in this concordance therefore apply to the distribution of employment, by sex. The application of the concordance to other LFS variables, such as unemployment, and other classificatory items such as state, age, full-time/part-time, and status in employment, may not be fully appropriate.
- The concordance is based on the comparison of occupation data for one time period - August 1996. Use of the concordance to derive estimates for earlier periods assumes that the proportions derived in August 1996 will also apply to other time periods. However the relative contributions of particular occupations in the overall employment market change over time. New occupations can emerge while others disappear. Since the concordance is a snapshot, these changes are not reflected when the concordance is applied to other time periods. For this reason, applying a concordance may produce unlikely results for some occupations.
The table on the following page provides data for employed persons by ASCO Second Edition, from August 1994 to August 1998. Between August 1994 and May 1996, the data have been created by applying the concordance to ASCO First Edition data. From August 1996, survey responses have been directly coded to ASCO Second Edition.
The concordance is available for each of the levels that apply to LFS data: Major Group, Sub-major Group, Minor Group and Unit Group. The concordance is available on request, in printed or electronic format. For further information about the concordance or the availability of data, contact Michael Johnson on Canberra 02 6252 6525 or Email: firstname.lastname@example.org.
- Methodological differences between the Census and the LFS may also affect the applicability of the concordance to LFS data. The LFS is conducted by trained interviewers who are able to obtain detailed occupation information. Since the Census is filled in by respondents, there is little control over the type of occupation information provided. Further, Census data were coded using computer assisted coding techniques, while LFS coding is undertaken manually by trained coders. These differences in methodology mean that the distribution of occupations derived from the Census could vary from the distribution that would have been obtained from the survey.
EMPLOYED PERSONS BY OCCUPATION (ASCO SECOND EDITION)
sales and service
sales and service