This section provides an overview and definition of key terms in the Torino Process monitoring framework.

• Youth: Population in the official age of entrance and participation in initial VET programmes.
• Adults: Population of working age (15+ years of age) not enrolled in initial VET programmes.
• Disadvantaged youth: This refers to socio-economic disadvantage and describes youth with access to below-average levels of financial, social, cultural, and human capital resources.
• Long-term unemployed: Long-term unemployment refers to the number of people who are out of work and have been actively seeking employment for at least one year.
• Inactive populations: Adults of working age who are outside of the labour force, meaning that they are neither employed nor registered as unemployed (that is, seeking employment)
• Lifelong learning: any learning activity undertaken throughout life, to improve knowledge, skills/competences and/or qualifications for personal, social and/or professional reasons.
• System performance: describes the extent to which the VET system delivers against a targeted selection of national and international obligations (commitments) to learners and other stakeholders in support of learning through life (lifelong learning - LLL).
• Initial VET: Vocational education and training carried out in the formal system of initial education (usually upper or post-secondary) before entering working life.
• Continuing VET: Formal or non-formal vocational education and training carried out after initial VET and usually after the beginning of working life.
• Adult education: Adult education or learning may refer to any formal, non-formal, or informal learning activity, both general and vocational, undertaken by adults after leaving initial education and training.

The system performance indices developed in the framework of the Torino Process, are based on a rich methodological framework. This framework relies on various principles and theoretical underpinnings to ensure that the design, implementation, and evaluation of the indices is plausible in terms of theoretical foundations, technical reproducibility, and statistical fitness. The primary aim of these indices is to offer insights that can guide the monitoring of countries and inform their policy planning, not to promote their comparative ranking.

While various options were available during the different phases of the construction of the indices, the final choices represent a series of decisions which were deemed adequate and appropriate to promote reliability and avoid bias, in full awareness that by their very nature, indices like those require constant refinement. Therefore, the construction and calculation of the performance indices will remain an ongoing process to address the following limitations:

1. Refinement of aggregations and analysis: the current version of the indices represents a sub-set of the national systems under analysis. While these are sufficient for the formulation of initial findings, future cross-country analysis will include a larger number of countries with possible alternative (dis)aggregations i.e., at regional or development level, which may also affect the formulas using in the calculation of the indices as well as their values. The methodological framework of the Torino Process monitoring allows for such extensions and refinement without jeopardizing the validity of results which have been released already.

2. Choice of evidence: while the goal of this exercise is to monitor equally the different areas of interest, their dimensions and related outcomes, different countries may rely on a different, country-specific mix of qualitative and quantitative indicators from a predefined list for all countries, as captured by the ICI and BPI metrics described in Section 1.2. This also applies to the last available (reference) year for the quantitative indicators, which may vary between indicators and countries within a five-year limit.