Data collection on occupations in the Netherlands The derivation of codes of ISCO and the national occupational classification Sue Westerman Mies Bernelot Moens

Development SBC92 Classification criteria: ‘level’, ‘specialisation’ and ‘task clusters’ For 5600 job descriptions the criteria values were determined Job descriptions were sorted on the classification criteria  1211 occupations Occupational categories were tested on statistical applicability Occupational categories were given a label

Revision of the SBC92 Better description of the labour market Criteria on level, specialisation and task clusters modernised Collecting new job descriptions Same method used for data collection Time schedule, the revised SBC will be finished in 2010

ISCO versus SBC ISCO ’88 lies not on the basis of the SBC92/SBC2010: no translation, new classification ISCO not detailed and systematic enough for the Dutch labour market Number of skill levels is not sufficient (4 in stead of 5) Two major groups have no skill level An efficient way of coding was developed, giving results on several occupational classifications

Coding survey information on occupations Step 1: Open text answers are collected Step 2: Job information from surveys is coded with provisional codes using three approaches Computer Assisted Coding by Interviewers (CACI) Automatic coding in batch Interactive coding by experts Step 3: Classification codes are assigned to coded job information (in batch) Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 1: questions on occupation Respondents are asked four questions The title of their job A description of the main tasks within this job Wether their position is an executive one, how many subordinates A description of the economic activity of the company or firm they work Answers recorded by the interviewer in a few key words Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 2: Computer Assisted Coding by Interviewers Coding acitivities performed by interviewers during CAPI-interviews Open text answers entered on laptop Laptop software evaluates the text strings and generates list of appropriate provisional code descriptions List of code descriptions presented to the respondent Respondent selects unique code description Approx. 80% of cases are succesfully coded in the field Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 2: Computer Assisted Coding by Interviewers Laptop software used in CACI depends on search files Search file contains information about occupations and corresponding provisional code: Search file as a kind of dictionary: using data from the classification documentation, list of synonyms ‘Historical’ search file taking into account the frequency with which a code has been assigned by a coding expert to a textstring in previous surveys Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 2: Computer Assisted Coding by Interviewers Laptop software compares open text answers with text strings in the search files and selects records that match Similarity is measured using a kind of metric (distance formula, the Levenstein metric) Records that are similar are presented to the respondent for further selection Too many suggestions  additional information is asked Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 2: Automatic coding in batch Open text answers for which no code could be found are coded at Statistics Netherlands editing of text strings: remove misspellings, special signs and certain text strings (the, a, of, for etc.) reducing the different text strings into a standardised text string by using synonyms for each of the four questions assigning a provisional code by using files with coded (combinations of) standard strings Only a small percentage (<1%) of cases are successfully coded in the ‘batch’ process Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 2: Interactive coding Open text answers for which still no code could be found are referred to coding experts at the statistical office (approx. 20%) Respondents answers Display when a provisional code is interactively assigned job: DELIVERYMAN OF BEDS tasks: DELIVER BEDS exec: econ: BEDS SPECIALIST SHOP proc. code: 01 selection prov.code: text: CHAUFF 985502 LORRY DRIVER (WFE)  name of the chosen provisional code  without further explication 985402 CHAUFFEUR: SMALL PASSENGER (< 9) VAN 985502 CHAUFFEUR: TANKER 985502 CHAUFFEUR: LORRY 985502 CHAUFFEUR: CARRIAGE OF GOODS (SIZE VAN/LORRY UNKNOWN) 985905 CHAUFFEUR WFE 985502 CHAUFFEUR/ DELIVERYMAN: LORRY 985403 CHAUFFEUR/ TICKET COLLECTOR: PUBLIC TRANSPORT 985502 CHAUFFEUR/ MOTOR MECHANIC: LORRY F4 outline F5 change F9 code AH help AP pause AA ok AO remark page 2 of 2 sel 0 You can thump in JOB TITLES CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 3: Provisional occupational code  occupational code Provisional codes are converted to the SBC- or ISCO-codes (in batch). Additional conditions: Employment status (wage earning, self-employed or unpaid family worker) Educational level Educational field Number of subordinates Values of these conditional variables are specified in decision tables Respondents answers CACI Interactive coding Batch coding Provisional codes Additional conditional variables SBC84 ISCO88 SBC92

Step 3: Provisional occupational code  occupational code, an example Provisional code: 24001 Provisional code description: Head technical service

Summary Use of so-called provisional occupational codes Separate operations for: Coding job information from surveys Assigning of classification codes to coded job information Consistent and reasonably fast coding of occupations ISCO as well as SBC-codes are derived from provisional occupational codes No direct linkage between the international and national classification of occupations (n:m) In SBC2010 we aim to have a direct linkage between the classifications