Concepts and conventions

The development of an organizational framework such as the National Occupational Classification (NOC) relies on the use of clear and defined concepts and the use of conventions. These concepts and conventions help gather information and structure it into the classification.

NOC classification criteria

The two major attributes used as classification criteria in developing the NOC are the broad occupational category and the skill level. Other factors, such as occupational mobility and the industrial sector, are also taken into consideration.

Broad occupational category: Represents the type of work performed, the field of study, or the industry of employment whenever industry-specific work experience is required for entry into occupation. The first digit of a NOC code represents the broad occupational category.

Skill level: Represents a broad aggregation of education, training, and work experience and also takes into account the complexity of the tasks and responsibilities associated with the job. The second digit of a NOC code represents the skill level.

NOC concepts

Job title: Represents the name given to a job or a position.

Occupation: An occupation is a set of jobs that are sufficiently similar in work performed. A job corresponds to all the tasks carried out by a particular worker to complete his or her duties.

Unit group: Represents one or several occupations combined together within the NOC. It also refers to the four-digit code used by the NOC.

Minor group: Represents the domain in which an occupation is carried out (occupational domain). It is an aggregation of several unit groups and thus represents the three-digit code used by the NOC.

Major group: Represents the broad occupational category and skill level of an occupation. A major group encompasses several minor groups and thus represents the two-digit code used by the NOC.

NOC conventions

Conventions that were adopted in order to harmonize the classification are discussed below.

Management occupations

Management occupations present a special problem for reliable coding of occupational survey responses. In many cases, there is little indication of the level of responsibility, the size of the enterprise or division managed, or the field of specialization.

Senior management occupations (major group 00) have been divided based on industry of employment into six unit groups.

Middle and other management occupations are divided into three major groups, 18 minor groups, and 42 unit groups based on specialization (e.g., unit group 0113 – Purchasing managers) or industry of employment (e.g., unit group 0132 – Postal and courier services managers). In certain cases, (e.g., unit group 0731 – Managers in transportation) groups defined by industry also contain managers in that specialization regardless of their industry of employment.

Managers are usually classified to the broad occupational category 0 – Management occupations. Within this category, the senior managers that are the top of a management hierarchy as denoted by terms such as president, chief executive officer, etc. are classified in major group 00 – Senior management occupations.

Managers with a management specialty, such as human resource management, are classified according to their specialty in NOC major group 01-05 – Specialized middle management occupations. However, senior managers with a specialist responsibility would be classified with senior management in major group 00 – Senior management occupations.

An attempt has been made to isolate many of the managers of small businesses by classifying managers of retail stores, restaurants, hotels and similar businesses in a separate major group 06 – Middle management occupations in retail and wholesale trade.

All other managers are classified according to the type of business managed within major group 07-09 – Middle management occupations in trades, transportation, production, and utilities.


As a general rule, the class of worker status, that is, whether the respondent works for wages or is self-employed, is not considered for classification purposes.

An exception is made for proprietors in retail trade, food and accommodation services, and residential home building. These are classified as managers to the following unit groups:

  • 0621 – Retail and wholesale trade managers
  • 0631 – Restaurant and food service managers
  • 0632 – Accommodation service managers
  • 0712 – Home building and renovation managers

Contractors are classified in several areas of the classification. General contractors in construction are classified in unit group 0711 – Construction managers. Renovation contractors and home building contractors are classified in unit group 0712 – Home building and renovation managers.

Contractors specializing in a specific trade such as plumbing, electrical, carpentry, etc., are classified together with supervisors to the appropriate unit group for that trade. That is, a plumbing contractor is classified within unit group – 7203 Contractors and supervisors, pipefitting trades.


Supervisors and foremen/women have generally been classified in skill level B.

In most cases, professional and technical occupations are supervised by managerial or professional personnel, respectively. However, where supervisors are identified for professional and technical groups, they are generally classified in the same unit groups as the occupations supervised.

Supervisors in the following occupational categories have been classified in supervisor unit groups or minor groups separate from the workers supervised:

  • administrative services occupations
  • nursing occupations
  • sales and service occupations
  • trades and transport and equipment operators
  • occupations in natural resources and agriculture
  • occupations in manufacturing and utilities.

Most minor and unit groups in the occupational categories listed above have a corresponding supervisory group. Occasionally, as in minor group 431 – Occupations in front-line public protection services, supervision is provided by managers and there are no corresponding supervisory groups in major group 43.

When a separate unit group does not exist, supervisors are classified with the workers supervised. For example, in most professional major groups there are no separate unit groups for supervisors, the one exception being unit group 3011 – Nursing co-ordinators and supervisors.

Technical occupations follow a similar rule and there are no separate unit groups for supervisors in this area.

Even when separate supervisory unit groups exist, "lead hands" are not classified as such, as previous research has indicated that supervision is usually only a minor part of such jobs.


All apprenticeable trades are included in skill level B. Their inclusion does not imply an exact equivalence of skill between all trades, but rather that they occupy a range that lies within the boundaries of this skill level category. Information on entry requirements is provided within each unit group description.

Inspectors, testers, and graders

Generally, inspectors who require post-secondary education have been classified in separate unit groups in skill level B or with technicians and technologists, also in skill level B. Other non-technical inspectors, testers, graders, and samplers have been included either in separate unit groups covering occupations in processing industries, or in unit groups of assemblers and fabricators in manufacturing industries. This is reflective of patterns of employment found within industries and the increasing responsibility for quality control that is placed on manufacturing production workers.

Apprentices and trainees

Apprentices and trainees have been classified in the same unit groups as the occupations for which they are training. Similarly, interns, residents, and articling students are classified with their respective professional groups.

This convention has been adopted out of necessity to prevent the proliferation of unit groups of apprentices. It is not intended to imply equivalence or interchangeability of apprentices or trainees with fully qualified workers.


Helpers are usually considered as labourers. Most helpers will be found in the building trades such as carpenter's helper, mason's helper, roofer's helper, etc. These jobs are not to be confused with formal apprenticeships and are not classified as tradesmen/women but are classified to unit group 7611 – Construction trades helpers and labourers.


Labourers are classified in separate unit groups in the following major groups:

  • 76 – Trades helpers, construction labourers and related occupations
  • 86 – Harvesting, landscaping and natural resources labourers
  • 96 – Labourers in processing, manufacturing and utilities
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