Occupational and Skills Information System (OaSIS) methodology

The Occupational and Skills Information System (OaSIS) framework is based on the Skills and Competencies Taxonomy (SCT). Descriptors were selected based on their inclusion in other occupational databases and their ability to be measured within the OaSIS. Standardized dimensions and scales were created to measure descriptors in the categories of Skills, Abilities, Personal attributes, Interests, Knowledge, and Work activities. For the Work context category, specific dimensions and scales were chosen for each descriptor based on the information needed. The following table outlines the measurement dimensions for each category, and the rationale for this methodology is described in further detail below.

Methodological basis for the development of the OaSIS

Measuring over 200 competency descriptors across 900 occupations using one or two dimensions for each would be lengthy and costly. To address this, a more efficient approach was adopted through using pre-existing data sources that offered consistent occupational information. The U.S. O*NET database was identified as a key resource, as it is both comprehensive and publicly accessible. As the competency descriptors in the OaSIS align with those in O*NET, this database served as the initial source for developing the Canadian occupational profiles.

Importing O*NET data into the Canadian framework consisted of two major steps:

1. The development of a concordance between occupational classifications in Canada and U.S. (consisting of more than 900 National Occupational Classification (NOC) sub-groups used in the OaSIS and around 930 O*NET occupations)
2. The establishment of a conversion method for measuring descriptors which transposed the 7-point O*NET scale to a 5-point OaSIS scale

O*NET measures descriptors in the Skills, Abilities, and Work activities categories using two dimensions: Importance and Proficiency level. However, a review of the data showed a high correlation between the Importance and Proficiency level ratings for most descriptors. Therefore, to streamline the development of OaSIS, Importance was replaced with Applicability, using a binary Yes/No scale to indicate whether a descriptor is relevant to a particular occupation. When a descriptor is considered applicable for an occupation, it is rated between 1 and 5. Although the Applicability rating is not displayed on the website, this distinction is reflected through the use of "0" for the Proficiency level, which signals that the descriptor is not applicable.

Another key difference between OaSIS and O*NET is how OaSIS measures descriptors on their level of proficiency and complexity. O*NET uses a 7-point scale, while a 5-point scale was adopted for the OaSIS. The 5-point scale was chosen to clearly differentiate between levels with an intuitive design. Data from the 7-point scale was converted to a 5-point scale using a mean-centered conversion formula, with cut-offs between levels determined using standard deviations from the mean. This approach allowed for a case-by-case assessment, as the mean and standard deviation are specific to each descriptor.

For descriptors categorized under Personal attributes and Work context, some of which align with Work Styles and Work Context in the O*NET framework, O*NET uses a 5-point scale, where level 1 indicates the descriptor is not required for the occupation and levels 2 to 5 indicate increasing level of importance or relevance. To maintain consistency with the other descriptor categories, OaSIS redesigned the measurement by adopting the Applicability scale (“Yes” or “No”) and removing the negative response from level 1 for the second scale option (e.g. Importance, Frequency or Duration) so that all the scale values indicate that some level is present for each descriptor if assigned a rating.

Once the concordance was established and the ratings converted, a comprehensive analysis was conducted for each OaSIS profile to reflect the Canadian context. This analysis involved a detailed review of various resources including:

• National Occupational Classification
• Career Handbook
• Essential Skills Profiles
• The Red Seal Program
• Occupational standards
• Provincial government sources
• Other relevant labour market sources

Notes

The Knowledge category’s descriptor ratings were not based on O*NET data but instead exclusively relied on the Canadian Rating Guide (CRG), discussed further below.

The Interests category was also developed using a distinct approach as it does not rely on measurement scale ratings but rather the assignment of Holland Codes (with one to three-letter codes). The Holland Codes (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional) were assigned based on how descriptive and characteristic the Holland work environment is for each occupation.

Canadian Rating Guide

To support the consistent evaluation of occupational requirements, a Canadian Rating Guide (CRG) was developed as a reference tool. The CRG played a central role in the initial review, as well as subsequent revisions, of ratings assigned to occupations through ensuring clarity in how these ratings were determined and interpreted while also promoting consistency and transparency in decision-making.

Separate CRGs were developed for the categories of Abilities, Skills, Work activities, Work context, and Knowledge. Each guide outlines the indicators used to assess descriptors and provides detailed explanations of the rating levels. These explanations include examples of typical tasks and occupations associated with each level, helping to illustrate how ratings were to be applied.

In addition to internal analysis, the CRG also aids in stakeholder understanding of ratings. For external users, the CRG serves as a key interpretive tool, allowing stakeholders to better understand how occupational data was evaluated and how rating levels reflect real-world job demands.

By using the CRG throughout the ratings review process, OaSIS ensures that occupational information is assessed systematically, presented clearly, and grounded in transparent methodology.

For access to the CRGs, please contact us.

Methodology for revisions

Following the initial development of the OaSIS, subsequent revisions and versions of ratings no longer utilize data from O*NET. Instead, the review process relies exclusively on Canadian sources of occupational information. In addition, with the creation of the Canadian Rating Guide (CRG), all occupational ratings are systematically reviewed against defined indicators to ensure consistency and alignment across all descriptors and occupations. The results of these revisions are being released as new versions of the OaSIS. To learn more about the versions and review process, visit the Versions of the OaSIS page.

Skills Match methodology

The Skills Match tool’s purpose is to help users explore occupations that are closely related to a specific occupation. The tool uses a similarity index based on the Occupational and Skills Information System (OaSIS) database, which contains 900 occupations, to identify occupations with similar competencies. The results highlight potential job transitions and career development.

The analysis focused on descriptors from four main categories of the Skills and Competencies Taxonomy (SCT): Skills, Abilities, Knowledge, and Personal attributes.

Determining similar occupations for each OaSIS occupational profile

The similarity index was calculated using the weighted Euclidean distance method, a distance-based technique that measures the difference between two variables to determine their similarity. A smaller Euclidean distance means the variables have a greater similarity. For the Skills Match tool, the variables are the descriptor ratings of two profiles and this calculation was completed for the Skills, Abilities, Knowledge, and Personal attributes descriptors rated in the OaSIS.

Based on the calculated distances between occupations, adequate thresholds were set to categorize occupations as “very similar”, “similar”, or “somewhat similar”.

For more information on how the similarity index is determined, please contact us.