Implementing Coding Tools for a New Classification

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Implementing Coding Tools for a New Classification

• John Perry, UK Office for National Statistics

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Operation 2007 - The players

• In the UK The Standard Industrial
  Classification of Economic Activities (SIC)
  (current version SIC (2003)
• In Europe NACE, the Nomenclature générale
  des activités économiques dans les
  Communautés européens (current version NACE
  Rev 1.1)
• In the UN ISIC, the International Standard
  Industrial Classification of all Economic
  Activities (current version ISIC Rev
  3.1)

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The UK SIC

• is a 5 digit classification system
• is required, by EU legislation, to be identical
  to NACE down to and including the 4 digit Class
  level
• contains a national 5th digit level which does
  not exist in NACE

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The Results changes in structure
SIC 2003 SIC 2007
NACE Classes 514 615
NACE Classes not split 414 537
UK Sub Class splits 285 191
Total Sub Classes 699 728
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ACTR as an aid to coding

• ACTR Automatic Coding by Text Recognition
• Developed by Statistics Canada
• ONS standard tool for coding, initially industry
  and occupation
• Replaces Precision Data Coder for industry coding
• Determines a code from a text description
• Extent of automation of process is controlled by
  parameters

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Knowledge Bases SIC2003

• ACTR relies heavily on indexes of standard
  descriptions
• Business descriptions from responses to the
  Business Register Survey
• Published index for the SIC2003
• The short descriptions for each SIC2003 code
• Standard descriptions for construction industry
  statistics
• Trade code descriptions for PAYE (Pay As You Earn
  Tax) employers
• Farm type descriptions
• With a total of gt 30,000 standard descriptions

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How ACTR works

• Each input description is converted to a standard
  form
• This is compared with the standard forms of
  descriptions held in the knowledge base
• The closeness is presented as a score between 0
  and 10
• The system has rules to determine whether the
  score is sufficient to confirm a match
• Requires a score of more than 7.5 to code
  automatically (our setting which may differ for
  other data sets)
• Lower scores are passed through interactive
  coding
• Coding does not depend on the order in which the
  knowledge bases are checked

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Extract from Business Register Survey
Questionnaire
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ACTR Process

• Supplied text Horticultural services
• HORTICULTURAL SERVICE
• Best fit index entry Sales and service of
  horticultural machinery
• HORTICULTURAL MACHINERY SALE SERVICE
• Score is 6.911 (out of 10)
• ACTR prefers SIC 2003 code 51880 (Wholesale of
  agricultural machinery and accessories)

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Interactive coding

• Scores below 7.5 are passed to clerical staff for
  coding interactively
• The system presents options in descending order
  of score
• If none of the choices appear good, staff modify
  the description
• Once a decision is made, the person coding
  confirms the choice
• The index description is then held on the IDBR.

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Introducing the SIC2007 (NACE Rev 2)

• New index files
• SIC2007 headings
• SIC2007 index
• Initially code forward from the SIC2003 using
  bridging codes these are codes for each
  knowledge base entry that link the SIC2003 and
  SIC2007
• Later will change to code backwards from the
  SIC2007
• Eventually dual coding will cease

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Impact of ACTR on IDBR at Micro Level

• Existing SIC 2003 is 01120 (Growing of vegetables
  etc)
• The preferred ACTR SIC 2003 is 51880 (Wholesale
  of agricultural machinery and accessories)
• The SIC 2007 comes from the bridging code
• SIC 2003 51880
• Bridging code MTOLR
• SIC 2007 46610
• SIC 2003 code will change but only when agreed

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Conversion to SIC2007

• ACTR will deal with units that have a suitable
  business description
• Conversion tables will deal with
• Units with descriptions that ACTR is unable to
  code (vague descriptions)
• Units without a description
• Units supplied through administrative sources
  (existing VAT traders, PAYE employers, Registered
  Companies)

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Creation of Conversion Tables

• Tables have been created to convert units from
  SIC2003 to SIC2007
• Using ACTR bridging codes
• Coding existing data through ACTR
• Producing cross-tabulation of SIC2003 to SIC2007
• Allocating on a probability basis rounded to
  nearest 5
• Validate relationships against the acceptable
  range of industries
• Best fit tables also produced for users who
  cannot accommodate probability based conversion

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Codingprocess
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Impact on the IDBR at the Macro Level

• Impact on SIC 2003 is only on those reporting
  units that have business descriptions for local
  units, where ACTR can code.
• ACTR codes 620,000
• ACTR does not code 210,000
• No business description 340,000
• Administrative data only 1,660,000
• Total local units 2,830,000
• SIC 2007 comes from the bridging codes only where
  ACTR codes otherwise SIC 2007 comes from
  conversion from SIC 2003

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A AGRICULTURE, HUNTING AND FORESTRY SIC
2003 B FISHING C MINING AND QUARRYING D MANUFACTUR
ING E ELECTRICITY, GAS AND WATER SUPPLY F
CONSTRUCTION G WHOLESALE AND RETAIL TRADE
REPAIR OF MOTOR VEHICLES H HOTELS AND
RESTAURANTS I TRANSPORT, STORAGE AND
COMMUNICATION J FINANCIAL INTERMEDIATION K REAL
ESTATE, RENTING AND BUSINESS ACTIVITIES L
PUBLIC ADMINISTRATION AND DEFENCE COMPULSORY
SOCIAL M EDUCATION N HEALTH AND SOCIAL
WORK O OTHER COMMUNITY, SOCIAL AND PERSONAL
SERVICE ACTIVITIES P PRIVATE HOUSEHOLDS
EMPLOYING STAFF AND UNDIFFERENTIATED Q
EXTRA-TERRITORIAL ORGANISATION AND BODIES
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Impact at SIC 2003 broad industry level
(provisional counts)
Section Starting stock In Out Net Change
A B 167,000 0.5 0.6 -0.1
C, D and E 180,000 5.9 5.2 0.7
F 260,000 1.4 0.9 0.5
G 530,000 2.4 2.5 -0.1
H 188,000 2.3 1.6 0.7
I 116,000 2.7 2.4 0.3
J 58,000 6.5 3.3 3.2
K 872,000 1.2 1.3 -0.1
L 29,000 10.4 11.1 -0.7
M, N and O 432,000 2.9 3.8 -0.9
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A Agriculture, Forestry And Fishing SIC
2007 B Mining And Quarrying C Manufacture D Electr
icity, Gas, Steam And Air Conditioning
Supply E Water Supply Sewage, Waste Management
And Remediation Activities F Construction G Wholes
ale And Retail Trade Repair Of Motor Vehicles
And Motorcycles H Transportation And
Storage I Accommodation And Food Service
Activities J Information And Communication K Finan
cial And Insurance Activities L Real Estate
Activities M Professional, Scientific And
Technical Activities N Administrative And Support
Service Activities O Public Administration And
Defence Compulsory Social Security P Education Q
Human Health And Social Work Activities R Arts,
Entertainment And Recreation S Other Service
Activities T Activities Of Households
U Activities Of Extraterritorial Organisations
And Bodies
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Correspondence between SIC 2003 and SIC 2007 for
local units coded by ACTR
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Implementation timetable
December 2006 NACE published
January 2007 SIC 2007 is published on NS website
February 2007 Development and tuning of data coder (ACTR) first release on 2007 basis, subject to revision
June 2007 Re-coding using ACTR
August 2007 New release of ACTR, using SIC 2007 index
November 2007 SIC 2007 Index published (consistent with ACTR August 2007)
January 2008 SIC 2007 fully implemented on the Register
2008 ???? ACTR SIC 2003 overwrites historic SIC 2003
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Conclusions

• The ACTR tool delivers considerable savings in
  terms of cost and burden on businesses compared
  to traditional survey approaches.
• The knowledge base is portable (i.e. independent
  of the coding engine), enabling sharing this with
  any interested parties, e.g. administrative data
  suppliers, to increase the consistency of coding.
• The use of bridging codes permits simultaneous
  coding to multiple classification systems,
  essential if periods of dual-coding are required.
  
• The knowledge base approach can help to inform
  the development of future versions of a
  classification, by providing a reference frame of
  business activity descriptions.