Widespread participation is essential if adult learning is to be effective in supporting individual careers, business performance and economic resilience. Broad and continuous participation also ensures that adults’ skills remain up to date and avoid more significant retraining when transitions to new jobs or roles are unavoidable. However, data from the 2023 Survey of Adult Skills show that participation in learning has stagnated or declined in most of the countries and economies participating in the survey. This chapter examines key aspects of participation in adult learning, focusing on the nature of adult learning, the level and intensity of participation, and the prevalence of flexible learning provision. It analyses how participation has evolved in the last decade and reflects on how these trends relate to those observed in foundational skills.
Trends in Adult Learning
Abstract
There are persistent differences across countries in participation in adult learning. Despite efforts to widen access and achieve common targets, participation in adult learning remains very uneven. On average across the OECD countries that participated in PIAAC, two in five adults engage in adult learning each year, but rates range from 58% in Norway to 13% in Korea. Nordic and English-speaking countries show the highest levels of participation.
Participation in adult learning has fallen in more countries than it has risen. This is despite adult learning being a central component of the policy response to the challenges of technological and economic change. Only in Ireland and Estonia has participation in adult learning increased over the past decade, by around 5 percentage points (pp). These increases are driven by higher participation in non-formal job-related learning. Participation has fallen in many countries, most notably in Korea (-26 pp) and Israel (-16 pp). (See Box 1.3 and Box 1.5 for a note on comparison between cycles.)
Declining adult learning participation is correlated with skills erosion. Countries experiencing the sharpest declines in literacy skills also tend to have declining participation in adult learning. While causality cannot be established, reduced formal, non-formal and informal learning opportunities may limit the ability of adults to maintain and develop foundational skills.
Formal learning plays a limited and declining role in the training of adults, but non-formal learning is widespread. Across the OECD, only 8% of adults participate in formal education, while 37% participate in non-formal learning. Countries with high levels of participation in formal education also tend to have high rates of non-formal learning, suggesting that robust adult learning systems encourage participation in both forms.
When adults participate in formal learning, they tend to take tertiary degrees. On average, 65% of formal adult learning is at tertiary level, ranging from 90% in Italy and the Czech Republic to less than 40% in Canada. In some countries, most formal adult learning is to achieve post-secondary diplomas (e.g. Canada, the United States), while in others most is second-chance education for adults (e.g. England [United Kingdom], France, Spain).
Non-formal learning is dominated by compliance-based training. Health and safety training is the most common form of non-formal job-related learning (18%), particularly in Finland, Ireland, Italy, Norway, Slovak Republic, where it accounts for 25% or more of non-formal job-related learning. IT and digital skills training is also common across countries (14%). While health and safety training is necessary, greater emphasis on broader skills development, especially digital and technical skills, is needed to match labour market needs.
Many non-formal courses are very short, raising concerns about long-term skills development for structural changes. 42% of non-formal learning activities last a day or less, and 40% last between a day and a week. Countries with shorter courses tend to have higher participation rates, but an over-reliance on short courses may limit the fundamental reskilling needed in the context of structural change. Modular and stackable learning pathways can ensure that short courses contribute to meaningful upskilling and reskilling.
There are substantial cross-country differences in informal learning at work: Two in three employed adults report learning new things at work at least once a month. Daily learning at work is highest in Portugal (41%), Chile (40%) and Spain (35%) and lowest in Poland (4%).
Adult learning (Box 1.1) has become a central component of policy responses to the challenges of technological, economic and social change. Over the past decade, countries across the OECD and beyond have made efforts to widen access to learning opportunities and increase their flexibility to better meet the diverse needs of adults. These efforts reflect a growing recognition that learning extends beyond initial education and that lifelong skill development is essential for both individual well-being and economic resilience.
This chapter provides a comprehensive analysis of adult learning participation in 2023, based on data collected through the 2023 Survey of Adult Skills. The Survey of Adult Skills is a product of the Programme for the International Assessment of Adult Competencies (PIAAC). It is a large-scale, computer-based household survey of adults aged 16-65, conducted in ten-year cycles. Its core objective is to assess adults’ mastery of key information-processing skills – literacy, numeracy and problem solving – that are essential for individuals to participate fully in society and for economies to thrive. Data collection for the 2023 Survey of Adult Skills took place in 2022 and 2023, covering 31 countries and economies. In addition to measuring skills, the survey provides insights into how adults develop and use these skills in everyday life and in the workplace (OECD, 2024[1]; OECD, 2024[2]).
This chapter examines key aspects of learning participation, focusing on the type of adult learning, the level and intensity of participation, and the prevalence of flexible learning options such as online and hybrid courses. It analyses participation trends over the past decade and reflects on how these trends relate to trends observed in information-processing skills. In doing so, it highlights the difficulties of comparing participation in adult learning between the 2023 Survey of Adult Skills and Cycle 1 a decade earlier. This is primarily due to changes in the wording of questions to capture participation in non-formal learning (see Box 1.3 and Box 1.5).
To exclude younger adults still in initial education and to concentrate on adults undertaking formal and non-formal learning that is more closely linked to jobs, the analysis focuses on job-related adult learning for the population aged 25-65, disregarding learning for other personal or societal reasons.1
In this report, adult learning is understood as the job-related learning of adults who have left initial education and training and entered working life. However, it should be noted that data from the 2023 Survey of Adult Skills does not make an explicit distinction between adults who participate in formal education above the age of 25 as part of prolonged participation in initial education and training, and those for whom this learning takes place after having worked for some time.
Job-related learning refers to education and training undertaken for the purpose of acquiring skills for a current or future job, while recognising that non-job-related ‘leisure’ learning can also provide individuals with valuable skills for the labour market.
Adult learning in this report encompasses three types of learning and is measured as follows in the 2023 Survey of Adult Skills:
Formal learning (accredited education and training) is intentional, institutionalised learning that has a minimum duration of one semester and is recognised by relevant authorities. Examples include vocational qualifications or a bachelor’s degree. In this report, all formal adult learning is considered to be job-related. The 2023 Survey of Adult Skills asked adults i) if they were currently studying towards a qualification, ii) if they finalised a qualification in the past 12 months before the interview; and iii) if they had interrupted studies towards a formal qualification in the past 12 months before the interview. All cases are included in the indicator for formal adult learning participation.
Non-formal learning (unaccredited education and training) is intentional, institutionalised learning that is either of short duration (less than one semester) or not recognised by relevant authorities. Examples include non-formal qualifications obtained from short courses and workshops. The 2023 Survey of Adult Skills asked adult if they participated in an organised learning activity, ‘different’ from studying towards a qualification, which could include training activities such as courses, webinars, workshops, lectures or private lessons. Adults were also asked whether these non-formal learning activities were job-related or not. Slightly over 80% of adults, on average, report that their training is job-related.
Informal learning is intentional, non-institutionalised learning that is less structured than formal and non-formal learning and can take place anywhere. Examples include learning from colleagues or learning by doing. The 2023 Survey of Adult Skills asked adults to assess the frequency at which they i) learnt new things at work; ii) learnt by doing, and iii) kept up to date with new products and services.
Source: Eurostat (2016[3]), Classification of learning activities – Manual: 2016 edition, https://ec.europa.eu/eurostat/web/products-manuals-and-guidelines/-/ks-gq-15-011; OECD (2023[4]), Flexible Adult Learning Provision: What it is, why it matters and how to make it work, https://www.oecd.org/content/dam/oecd/en/topics/policy-sub-issues/adult-learning/booklet-flexibility-2023.pdf/_jcr_content/renditions/original./booklet-flexibility-2023.pdf.
Adult learning takes three main forms: formal, non-formal and informal (see Box 1.1). Formal learning is structured, deliberate and leads to a recognised qualification, usually provided by educational institutions. Non-formal learning is also structured but shorter and more flexible, often taking place in workplace training, workshops or community courses. While traditionally separate from formal education, non-formal learning is increasingly being certified and included in national qualifications frameworks, blurring the boundaries between the two forms. This report focuses on non-formal learning activities that respondents reported as being job-related. Informal learning, by contrast, is unstructured and occurs through everyday activities, for example in learning by doing or learning from colleagues and supervisors. Comparing participation in different types of learning – formal, non-formal and informal – helps policymakers to understand and benchmark the performance of their adult learning systems.
Two in five adults participate in formal or non-formal adult learning
Two in five adults in the OECD area2 participate in formal or non-formal adult learning (Figure 1.1). Participation rates vary considerably between countries, with some countries achieving more than three times the rates of others. The highest rates were recorded in Finland and Norway (both 58%), closely followed by the United States (55%), Denmark (54%) and New Zealand (53%). At the other end of the spectrum, participation was comparatively low in Korea (13%), Croatia (20%) and Poland (21%). These differences highlight regional patterns: Nordic and English-speaking countries tend to have relatively high participation rates, while lower rates are more common in Southern, Central and Eastern European countries. This may reflect differences in the accessibility, relevance, and flexibility of adult learning systems, adult learning cultures and labour market structures.
Share of adults who participated in formal or non-formal job-related adult learning, %
Note: Adults aged 25-65, formal and non-formal job-related learning in the 12 months prior to the survey. OECD is an unweighted average of all participating member countries. See Box 1.1 for a precise definition of job-related adult learning.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported in the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
In all countries participating in the 2023 Survey of Adult Skills, adults are more likely to participate in non-formal learning than in formal learning (Figure 1.2). On average across the OECD, 8% of adults participate in formal learning, while 37% of adults participate in non-formal learning (Panel A). There is some overlap between the two types of learning, with a proportion of adults participating in both (Figure 1.2 B). On average, 4% of adults participate in both formal and non-formal learning, 32% in non-formal learning only and 4% in formal learning only. The largest overlaps occur in countries with the highest participation rates, such as Finland and the United States, where more than 8% of adults participate in both types of learning.
Participation in formal adult learning tends to be highest in countries with the highest overall participation rates, such as Finland, Sweden and the United States (all 12% or above), and lowest in Japan (1%) and Poland (2%). A similar pattern is observed for non-formal job-related learning, with Finland, Norway and the United States displaying participation of 50% or above. The lowest rates are observed in Korea (9%), Croatia (17%) and Poland (19%).
Share of adults who participated in formal or non-formal job-related learning in the 12 months prior to the survey, %
Note: Adults aged 25-65. OECD is an unweighted average of all participating member countries. See Box 1.1 for a precise definition of job-related adult learning.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
There is a strong positive correlation between participation in formal and non-formal learning at the country level. Countries with high levels of participation in formal adult education also tend to have higher levels of non-formal learning (Figure 1.3). This suggests that adult learning systems are generally more developed in some countries than in others, based on lifelong learning cultures, institutional frameworks that encourage participation in both formal and non-formal adult learning and the characteristics of national industrial structures.
Looking beyond this general pattern, however, there are important variations that provide further insights into the functioning of adult learning systems. Some countries – such as Estonia, Japan, and Norway – have significantly higher levels of non-formal learning than would be expected given their levels of formal participation. This suggests that these countries place a strong emphasis on continuous skills development through shorter, more flexible learning opportunities outside traditional educational settings. It may also indicate the existence of policies to promote employer-led training, incentives for continuous professional development, or a strong provider landscape that facilitate participation in non-formal learning. Conversely, countries such as Chile, Israel and Korea show a stronger emphasis on formal learning, with comparatively lower levels of non-formal learning participation. This may reflect systems where formal qualifications are important for skill recognition and career progression, potentially making non-formal learning less attractive or necessary. It may also reflect a structural preference for qualification-based learning pathways, where job-related training is more likely to take place in traditional educational institutions than in the workplace.
Finally, the difference in participation rates between formal and non-formal learning in a given country may be related to the age at which adults are most likely to complete tertiary education and to the overall age composition of the adult population. For example, if younger adults, who are more likely to pursue a tertiary degree, represent a comparatively small proportion of the population, this could result in lower participation rates in formal learning than in non-formal learning.
Countries seeking to increase participation in adult learning should consider not only the quantity but also the balance of learning opportunities available, ensuring that both formal and non-formal pathways are available to support skills development in an accessible and flexible way.
Correlation between the non-formal job-related and formal learning participation rate
Note: Adults aged 25-65. OECD is an unweighted average of all participating member countries. See Box 1.1 for a precise definition of job‑related adult learning.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Most people participate in non-formal adult learning at some point in their life
In many countries, participation in non-formal learning at some point in life is the norm. In Denmark, Estonia, Finland and Norway almost all adults – more than nine out of ten or more – report having participated in non-formal learning during their lifetime (Figure 1.4). In Korea, by contrast, just over one in three adults say to have ever participated.
Countries with high levels of lifelong participation also tend to have higher proportions of adults who have participated in learning in the last 12 months. This pattern may indicate that some countries have well-established learning cultures and systems that support sustained engagement, enabling adults to return to learning throughout their lives. By contrast, a higher share of less recent learning experiences may signal a deterioration in learning opportunities, whether due to reduced access, weaker incentives or changing perceptions of the value of adult learning. These trends underline the importance of policies that not only encourage one-off participations but ensure that learning remains accessible and relevant over time.
By capturing both recent and longer-term training histories, the 2023 Survey of Adult Skills improves the understanding of who participates in learning and when, providing a richer basis for analysing lifelong learning and its implications for policy. For example, recent learning (within the last five years) seems to be more closely associated with positive outcomes such as higher earnings and employment. At the same time, the data highlight gaps: older adults and those with lower levels of education are more likely to have participated in training more than five years ago, reflecting the challenges of maintaining access to learning opportunities over time (OECD, Forthcoming[6])
Share of adults who participated in non-formal learning at any time in their life, %
Note: Adults aged 25-65, non-formal learning. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Informal learning is extremely common, but not everywhere
Informal learning is a part of life and of working life in particular. However, it can be difficult to measure (Box 1.2). Most employees regularly acquire new knowledge and skills in their job, although the frequency of such learning varies considerably between countries (Figure 1.5). On average across the OECD, more than nine out of ten employed adults report that they learn new things at work at least occasionally (Panel A): 22% say this happens every day, while 23% report learning at least once a week, 23% at least once a month and 24% less than once a month. Portugal (41%), Chile (40%) and Spain (35%) stand out as the countries where employees are most likely to say they learn new things every day, while Poland (4%), Lithuania and Korea (9%) have the lowest shares. Other dimensions of informal learning have similarly large gaps in the share of adults who report informal learning on a daily basis. Switzerland has the highest proportion of employees reporting that they learn at least once a week or more (66%). At the other end of the spectrum, more than one in five employees in Lithuania and Korea say they never learn anything new at work.
Informal learning is a critical component of adult learning. It encompasses activities embedded in everyday tasks and interactions, making it a vital yet challenging area to measure and understand. Typical examples of informal learning include learning by doing, engaging with others and keeping abreast of new developments.
The 2023 Survey of Adult Skills introduces a more detailed approach to measuring informal learning than the previous cycle, allowing a better understanding of how individuals acquire skills outside structured learning environments. In this second cycle of the Survey, informal learning is captured by three key indicators:
Learning new things – how often an individual’s job involves learning new things.
Learning by doing – the extent to which individuals develop skills and knowledge by carrying out their regular activities.
Keeping up to date – how often individuals stay informed about new products, services or developments relevant to their work or interests.
The first cycle of PIAAC already included the two latter indicators – ‘learning by doing’ and ‘keeping up to date’, which allows for trend analysis on these items. The addition in 2023 of ‘learning new things’ provides an additional and more direct way to assess informal learning.
Source: OECD (2024[2]), Survey of Adult Skills – Reader’s Companion: 2023, https://doi.org/10.1787/3639d1e2-en.
A similar pattern emerges for learning by doing, albeit with slightly higher incidence overall (Panel B). On average, 28% of employees across the OECD report that they learn by doing on a daily basis. While Chile and Portugal remain among the top countries for daily engagement, France and New Zealand move into the top five, suggesting that learning by doing may be particularly embedded in the work environment in these countries, compared to other ways of informal learning. Conversely, the countries with the highest proportions of people who never learn by doing – Lithuania (28%), Italy and Korea (both 22%) – are broadly consistent with those reporting low engagement in learning new things.
When it comes to keeping up with new products and services, 20% of employees in the OECD on average engage in this type of learning on a daily basis, while 14% say they never do so – the highest proportion of non-participants among the three informal learning indicators (Panel C). While cross-country patterns are similar to what has been observed for the other informal learning indicators, Hungary stands out, with 32% of employees keeping up with new products and services every day, despite lower rankings on the other two measures of informal learning.
The differences observed between the three indicators of informal learning suggest that they capture different but complementary dimensions of learning at work. While learning new things and learning by doing may reflect the general dynamism of the workplace and the complexity of tasks, keeping up with new products and services may be more sector specific. This could explain why some countries, such as Hungary, score higher on this measure despite lower engagement in other forms of informal learning.
Share of employed adults engaging in informal adult learning, by frequency, %
Note: Adults aged 25-65 who were employed in the 12 months prior to the survey. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]) Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Differences between countries are likely to reflect differences in occupational structures, workplace cultures, hiring practices, and general economic conditions. In countries with high proportions of adults who never engage in informal learning – such as Lithuania, Korea and Italy – job roles may be narrower and involve lower levels of autonomy, limiting opportunities for on-the-job learning. Conversely, the high levels of informal learning in countries such as Switzerland and Portugal may reflect work environments where continuous skills development is more embedded, whether through job design, employee initiative or workplace culture. These differences may also be shaped by the degree to which lifelong learning is culturally valued and how aware workers are of their own skill development.
These findings highlight the need for a more detailed understanding of how informal learning is embedded in different labour markets. Future analysis of its relationship with factors such as job autonomy, task complexity, ICT use, and structured learning systems could help to identify instances where informal learning complements or substitutes formal and non-formal training. Such evidence could inform policies aimed at strengthening workforce adaptability in response to ongoing technological and economic transformations.
Understanding the intensity, content and modes of adult learning provides deeper insights into how individuals engage with education and training. Examining the frequency with which adults participate, the subjects they study, and the ways in which learning is delivered, helps policymakers determine whether current provision matches labour market needs and individual learning preferences.
When adults participate in formal learning, they tend to take tertiary degrees…
Formal learning includes structured programmes leading to recognised qualifications such as upper secondary diplomas, vocational certificates, or tertiary degrees. Some adults take up formal education to catch up on previously missed learning, such as obtaining upper secondary diplomas later in life (“second chance education”). Others participate in formal education to gain new qualifications, such as master’s degrees, for career progression or reskilling.
Patterns of qualifications taken through formal adult learning vary considerably between countries, reflecting differences in initial and continuing education and training systems, learner structure and policy priorities (Figure 1.6). On average across countries, most formal adult learning takes place at tertiary level (65%), ranging from 90% in Czechia and Italy to under 40% in Canada. In some countries, post-secondary non-tertiary education make up large shares of formal adult learning. This includes Canada, Ireland, Singapore and the United States. Canada and the United States, for example, both have extensive college system in which adults can gain post-secondary diplomas that provide entry to a number of professions. A final group of countries has relatively high shares of second-chance education (30% of formal adult learning or more). This includes England (UK), the Flemish Region (Belgium), Portugal and Spain.
Share of adults currently in formal education, by education level they are studying towards, %
Note: Adults aged 25-65 currently in formal education. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
…while non-formal learning often focuses on health and safety or computer skills
Examining the content of non-formal learning provides insights into the types of skills adults are developing and how these relate to labour market needs. The data show that non-formal job-related learning covers a wide range of topics, although certain themes dominate. The most common training subject across countries is health and safety and first aid (18%). This is a pattern that has been observed in previous research and is in line with regulatory requirements in many sectors, where compliance-based training is often mandatory (OECD, 2021[7]). The extent to which health and safety training dominates varies: in Finland, Ireland, Italy, Norway, Slovak Republic it makes up 25% or more of non-formal job-related training, but only 9-10% in Austria, Israel and Switzerland (see Appendix Tables, available on the support materials page of this publication).
In addition, training in computer and software skills is widespread across countries (14%), reflecting the need to adapt to increasingly digitalised workplaces. The share of IT-related training is largest in Israel, Spain and Singapore (all 19%) and lowest in Italy, Japan and Poland (10% or less) (see Appendix Tables, available on the support materials page of this publication). Across countries, training in customer and client services (11%), teamwork and leadership skills (9%) is also common, highlighting the importance of transversal skills Although only 14% of training activities focused primarily on computer or software skills, a larger proportion of training sessions nevertheless involved participants learning how to use computerised equipment or navigate digital processes more effectively (see Chapter 3, Box 3.1).
Strong information-processing skills – such as literacy and numeracy – are the basis for adults to adapt to changing job demands and to engage in further learning (OECD, 2024[1]), yet relatively few adults participate in job-related training activities focused on these skills across countries (around 1%). Such training may take place in other non-job-related contexts in many places. However, ensuring that those who would most benefit from literacy and numeracy training have access to such courses – in particular in the context of job-related training for individuals with low foundational skills – remains a challenge.
For policymakers, these findings highlight the need to reflect on providing non-formal learning opportunities that support labour market needs. While health and safety training is necessary and often legally required, there is also a need for broader skills development, including in areas such as literacy, numeracy, digital and technical skills. Understanding which types of training are most widely available – and who is accessing them – can help shape policies that promote more labour-market relevant adult learning.
Share of non-formal job-related learning activities with the named focus, OECD average, %
Note: Adults aged 25-65, non-formal job-related learning. Respondents were asked to identify a single primary focus of the most recent adult learning activity undertaken. See Box 1.1 for a precise definition of job-related adult learning.
Source: OECD (n.d.[5]),Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Non-formal learning that leads to a certificate can make learning more recognisable to employers, thereby increasing its value in the labour market. On average across OECD countries, 62% of non-formal learning activities lead to a certificate (Figure 1.8). Country differences highlight different approaches to skills recognition. Non-formal learning is more likely to be certified in southern European countries such as Croatia, Italy, Portugal and Spain, and in central European countries such as Austria and Germany. This reflects institutional frameworks where qualifications and formal recognition play a central role in career progression. In these contexts, certification can enhance the transferability of skills across employers and sectors, providing workers with tangible evidence of acquired skills that can be used for career advancement.
In contrast, in countries such as Czechia, Denmark, Finland, Israel, Japan and the United States, around half or less of all non-formal learning opportunities lead to certification. First, apart from Japan, these are countries with relatively high levels of participation in formal adult learning, suggesting that certification may remain primarily the domain of formal rather than non-formal adult learning. In systems where formal adult learning is more widely used, non-formal learning may serve as a complementary or supplementary tool for developing skills, rather than as a substitute for formal qualifications. Second, some of these countries may have more flexible labour markets, where skills can be signalled through work experience and employer-based assessments. In such systems, employees and employers may place more emphasis on demonstrated skills rather than on officially certified learning outcomes.
Share of non-formal learning leading to a certificate, %
Note: Adults aged 25-65, non-formal job-related adult learning in the 12 months prior to survey. OECD is an unweighted average of all participating member countries. See Box 1.1 for a precise definition of job-related adult learning.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Shorter learning opportunities are correlated with higher average participation rates
Most non-formal job-related learning activities are relatively short, with 42% lasting a day (8 hours) or less and a further 40% lasting between a day and a week (40 hours) on average across OECD countries (Figure 1.9). Longer courses are much less common, with 15% of activities lasting between a week and a month and only 4% lasting longer than a month. There is notable cross-country variation. In England (UK), short courses dominate, with more than half (56%) lasting a single day or less. In contrast, week-long training activities are most common in Korea and Singapore (both 52%), as well as in France and Italy (both 49%). Extended non-formal learning of more than one month is most common in Austria and Spain (both 8%) and Israel (7%).
Training duration for unemployed adults is longer, on average across OECD countries, than for adults who are employed. While amongst adults who are employed, just 15% participated in non-formal job-related learning activities that lasted for longer than a week, 38% of unemployed adults did so. There are several reasons for this. First, unemployed adults have fewer time constraints, as they are not balancing work‑related responsibilities (see Chapter 3). Additionally, the training needs of employed and unemployed adults often differ. Employed adults typically require short, targeted learning activities to acquire specific skills that complement their current job tasks. In contrast, unemployed adults may need more comprehensive training to develop a broader range of skills, making them more competitive in the job market and improving their employability.
It is important to note that these figures do not capture the total annual hours spent by an individual in non-formal learning, as respondents only report the duration of a single activity they consider the most important. Many adults may participate in multiple learning opportunities throughout the year, potentially accumulating significant learning time across different activities.
There is a clear negative correlation between the median duration of non-formal learning and the share of adults participating in it (Figure 1.10). In other words, countries where non-formal learning tends to be of shorter duration tend to have higher participation rates, while countries with longer training commitments tend to have lower participation rates. This pattern suggests that the time commitment for taking part in a given adult learning activity – and perhaps the higher costs that may be associated with longer learning opportunities – plays a crucial role in determining engagement with adult learning opportunities.
However, similar training intensities do not always correspond to similar participation rates. For example, Croatia and Denmark have a similar median duration of training (about 1.5 days), but Denmark’s participation rate in non-formal learning is more than 2.5 times that of Croatia. This highlights that other factors, such as the availability and relevance of training opportunities, employer and other financial support, play an important role in shaping participation patterns beyond the duration of training itself.
Share of non-formal learning, by duration, %
Note: Adults aged 25-65, non-formal job-related learning. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Correlation between non-formal learning participation rate and median training duration
Note: Adults aged 25-65, non-formal job-related learning. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Countries where non-formal learning predominantly takes the form of short courses tend to have higher participation rates, suggesting that accessibility is improved when a given training requires less time commitment. However, strong reliance on very short courses raises concerns about their ability to equip adults for more fundamental changes in the labour market, in particular where the stackability of these types of courses towards qualifications is limited. If very short courses become the dominant form of learning and adults do not take part in a commensurately greater number of smaller, more modular activities, there is a risk that skill development will remain marginal rather than providing the substantial retraining needed to facilitate occupational mobility or economic transition.
Ensuring a balance between accessibility and depth in adult learning systems is therefore essential. While short, targeted courses can be effective in maintaining the adaptability of the workforce, there must also be pathways for more substantial skills acquisition. The development of modular learning and stackable qualifications help facilitate this, allowing adults to build up deeper skills over time without the need for long, continuous periods away from work (see Chapter 4). As labour markets continue to evolve, promoting a system that combines flexibility with opportunities for sustained skills development will be key to ensuring the long-term resilience of the workforce.
Non-formal learning still mostly takes place face-to-face
Flexibility in adult learning is essential for individuals to balance work, family, and other commitments. The mode of delivery – whether face-to-face, online, or blended – as well as the structure and timing of learning activities, significantly affect accessibility, engagement, and effectiveness (OECD, 2023[4]). Training delivered in a single block, at regular intervals, or asynchronously can shape participation patterns, particularly for those with limited time. Understanding these modes and formats provides insights into how learning opportunities are structured across countries and highlights key considerations for policy design to enhance access and responsiveness.
The COVID-19 pandemic accelerated the adoption of new learning modes, making use of technological advancements (OECD, 2020[8]). Yet, on average across OECD countries, face-to-face training remains the dominant mode, with 53% of non-formal learning taking place face-to-face with an instructor. Online learning accounts for 34% of training, while blended learning – combining face-to-face and online elements – accounts for the remaining 14%.
However, these averages hide substantial differences between countries. Some countries have much higher rates of online and blended learning. In Canada, Chile, England (UK), Latvia and the United States, more than 60% of non-formal learning takes place at a distance, either entirely online or through a mix of online and face-to-face sessions. In contrast, in countries such as Czechia, Denmark, France and the Slovak Republic, face-to-face training remains the dominant mode with more than two thirds of non-formal learning taking place in this setting. This may reflect a preference for practical instruction, the nature of the training programmes offered, structural factors such as limited digital learning infrastructure or regulatory constraints.
Across the OECD, most non-formal learning – three in five – takes place in blocked sessions (Figure 1.12). A further 35% of learning activities follow a recurring schedule over several weeks or months, potentially allowing for deeper skill acquisition and better retention. Meanwhile, asynchronous learning – where there are no fixed times for participation – is the least common, accounting on average for less than 5% of training activities.
Hungary, Japan and the Netherlands stand out with the highest shares of asynchronous learning, indicating a greater reliance on flexible, self-paced formats. Meanwhile, Israel and Korea have the highest proportions of recurrent training sessions over several weeks or months. This is consistent with these countries reporting some of the highest proportions of longer training courses of one week or more.
Share of non-formal learning by mode of delivery, %
Note: Adults aged 25-65, non-formal learning in the 12 months prior to the survey. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html . Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Share of non-formal learning by frequency of delivery, %
Note: Adults aged 25-65, non-formal learning in the 12 months prior to the survey that was longer than 1 day. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
The way in which training is delivered has important policy implications, as different modes offer different levels of accessibility and flexibility. While face-to-face training remains the most common format, online and blended options help to reach those with geographical or time constraints. The scheduling of training is also important. Blocked or consecutive days may be easier for employers to accommodate but may exclude those who cannot take time off. Regular sessions over weeks or months support sustained learning but require long-term commitment, while asynchronous formats offer maximum flexibility but are less common. Understanding these patterns can help design more inclusive and effective learning opportunities that support workforce adaptability.
Tracking changes in adult learning participation over time is essential to understand whether efforts to expand learning opportunities are leading to real increases in engagement. The Survey of Adult Skills (PIAAC) provides a unique opportunity to analyse changes in participation across a large number of OECD countries. However, making comparisons between cycles is not straightforward, primarily due to a difference in how respondents were being asked about their participation in non-formal learning activities (see Box 1.3 and Box 1.5). While measurement of formal and informal learning has stayed consistent across survey cycles, trends for non-formal learning should be interpreted with extreme caution and ideally be triangulated with other data sources (Box 1.5).
When interpreting these developments over time, it should also be considered that of the 27 countries that participated in both cycles of the Survey of Adult Skills, not all countries participated in the first round of the first cycle in 2012. Chile, Israel, Lithuania, New Zealand and Singapore participated in 2015 and Hungary in 2018. Comparisons between the first and second cycle are therefore made between different time periods for these countries.
Structured adult learning includes both formal education (such as school, university and vocational qualifications) and non-formal learning (such as workplace training, workshops and private courses).
The measurement of formal adult learning has remained mostly stable over the cycles of the Survey of Adult Skills.3 The approach to measuring non-formal learning has changed in an effort to improve the survey (see Box 1.5).
Previously, non-formal learning was captured through a series of detailed questions on different types of training activities. Respondents were then asked whether the final type of training activity they reported was job-related (if they had reported multiple types of training activity). In the second cycle, this was simplified into a single question, making the survey faster to complete while still covering the same concept. Respondents who had reported more than one training activity were asked to refer to a job-related training activity when responding to subsequent questions.
As a result, the trends observed reflect both real changes in participation and differences in measurement. As non-formal learning represents the larger share of structured adult learning, these changes also affect the measurement of overall participation rates. While trends should be interpreted with caution, the underlying concept of participation remains comparable. Taken together with other sources (see Box 1.5), the analysis of trends still provides valuable insights.
Further information on the design methodology for the Survey of Adult Skills is available on the PIAAC website (https://www.oecd.org/en/about/programmes/piaac/piaac-data.html) and in the PIAAC Reader’s Companion (OECD, 2024[2]).
Adult learning has stagnated or declined over the past decade
Participation in formal and non-formal learning has declined in more countries than it has increased over the past decade (Figure 1.13). Amongst the few countries that saw increases in adult learning participation, Estonia and Ireland saw the only significant increases, by around 5 percentage points. Other countries recorded smaller increases, including England (UK), France, the Flemish Region (Belgium), Italy and the United States, but these were not statistically significant. Conversely, there were significant falls in participation in several countries. Korea recorded the largest decrease (26 percentage points), followed by Israel (16 percentage points), Poland and Singapore (both 11 percentage points).
These trends highlight the different trajectories of countries with historically high participation rates. Some countries such as Finland, Norway, and the United States, have maintained high levels of participation over the past decade. Conversely, Denmark and New Zealand, which had the highest adult learning participation rates in the first cycle, experienced declines of 5 and 8 percentage points. Despite this decline, they maintain high participation rates compared to the OECD average.
Percentage point change in formal and non-formal learning participation, comparison between cycles
Note: Adults aged 25-65, formal and non-formal learning. Cycle 2 data refer to 2023; data for Cycle 1 refer to 2012, except for Chile, Israel, Lithuania, New Zealand, and Singapore (2015) and Hungary (2018). See Box 1.3 for a note on comparison of data between Cycle 1 and Cycle 2. OECD is an unweighted average of all participating member countries. Results that are not statistically significant at the 5% level (p > 0.05) are shown in striped bars.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2012, 2015, 2018, 2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
While adult participation in formal learning has generally declined according to the 2023 Survey of Adult Skills, trends in non-formal learning have been more mixed, with some countries experiencing increases. As shown above, only in Ireland and Estonia has participation in adult learning increased over the past decade, by around 5 percentage points (pp). These increases are driven by higher participation in non-formal job-related learning. This reflects the growing role of non-formal learning in meeting immediate labour market needs and providing flexible upskilling opportunities.
On average across OECD countries, participation in formal learning has fallen by more than 2 percentage points between survey cycles (Figure 1.14, Panel A). No country has seen a statistically significant increase in formal adult learning, but large and significant declines of 5 pp and more were observed in Ireland, Israel, New Zealand, Norway and Singapore. These declines may reflect changing policy priorities, as rapid structural changes in the labour market have led many governments to try and reduce the age at which adults graduate from tertiary education and to emphasise shorter, more targeted learning opportunities (typically provided in non-formal settings). This trend may also be influenced by wider structural societal changes, such as an ageing population, as younger people are more likely to participate in formal adult learning (see Chapter 2).
Changes in participation in non-formal job-related learning are more varied. Five countries recorded significant increases (England [UK], Estonia, the Flemish Region (Belgium), Ireland, Italy). Among these, Ireland and Estonia saw particularly notable rises, with increases of 10 and 6 pp respectively. In contrast, 14 countries experienced significant declines, with the highest decline recorded in Korea (-28 pp) (Figure 1.14, Panel B). While there has been an average decline of 3 pp across the OECD, this has been from a much higher base, so the relative decline is less pronounced than the one observed for formal learning.
Changes to the formal education system geared at helping students to finish tertiary education earlier, and a drop in the relative share of the population who are in early adulthood (and hence may be more likely to be pursuing formal education past the age of 25) may also contribute to the decline in formal learning participation. As noted in Box 1.3, care should be taken in interpreting these results, given slight changes between Cycle 1 and Cycle 2 in how questions on adult learning were administered.
Percentage point change in formal and non-formal job-related learning participation, comparison between cycles
Note: Adults aged 25-65, formal and non-formal job-related learning. See Box 1.1 for a precise definition of job-related adult learning. Cycle 2 data refer to 2023; data for Cycle 1 refer to 2012, except for Chile, Israel, Lithuania, New Zealand, and Singapore (2015) and Hungary (2018). See Box 1.3 for a note on comparison of data between Cycle 1 and Cycle 2. OECD is an unweighted average of all participating member countries. Results that are not statistically significant at the 5% level (p > 0.05) are shown in striped bars.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2012, 2015, 2018, 2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Overall trends in participation are not simply the sum of changes in formal and non-formal learning, as some adults engage in both types. Figure 1.15 decomposes changes in adult learning participation to account for potential overlaps between formal and non-formal learning. It distinguishes between changes in participation in only formal, only non-formal job-related and both. In some countries, such as Ireland and Estonia, the increase in non-formal learning has been the primary driver of overall participation growth, while formal learning has remained relatively stable. Conversely, in countries like Israel and Korea, steep declines in non-formal learning have not been offset by changes in formal learning, contributing to an overall reduction in participation.
This decomposition highlights the importance of considering overlaps when analysing trends in adult learning. A decline in one type of learning does not necessarily mean a proportional drop in overall participation, as shifts between formal and non-formal learning can partially compensate for each other.
Decomposition of changes in adult learning participation rates, percentage points
Note: Adults aged 25-65, formal and non-formal job-related learning. The cross represents the overall change in formal and non-formal job-related adult learning participation. Cycle 2 data refer to 2023; data for Cycle 1 refer to 2012, except for Chile, Israel, Lithuania, New Zealand, and Singapore (2015) and Hungary (2018). See Box 1.3 for a note on comparison of data between Cycle 1 and Cycle 2. See Box 1.1 for a precise definition of job-related adult learning. OECD is an unweighted average of all participating member countries.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2012, 2015, 2018, 2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
With declines in both formal and non-formal learning observed in many countries, trends in informal learning can give further insights to the changing patterns of adult learning. If informal learning remained stable or increased over the past decade, it could indicate that adults are compensating for reduced participation in formal and non-formal learning by relying more on learning-by-doing, peer learning or self-directed skills development. By contrast, a decline in informal learning could signal a wider decline in opportunities for skills development – whether due to changing workplace dynamics, reduced employer-sponsored training or fewer opportunities for experiential learning.
On average participation in informal learning has decreased by 2 percentage points in the past decade (Figure 1.16). While five countries – England (UK), Ireland, Korea, the Netherlands and Hungary – have seen significant increases in learning-by-doing, many others, most notably Italy and Poland, have seen significant declines. Where opportunities for informal learning have expanded this may be due to changes in working practices, increased recognition of experiential learning and government support for informal learning in the workplace. Declines, on the other hand, may indicate shifts in job tasks or broader economic trends, such as business cycle fluctuations, that are reducing opportunities for learning at work.
From a policy perspective, these findings highlight the importance of ensuring that learning-by-doing remains an integral part of skills development. While investments in formal and non-formal learning are essential, they cannot fully replace the value of regular experiential learning, which helps adults apply and reinforce skills in real-world settings. Policies that support learning in the workplace – such as promoting mentoring schemes, encouraging job rotation and designing working environments that are conducive to continuous learning – can help counteract the decline in informal learning seen in many countries. In addition, in countries where informal learning is declining, policymakers may need to consider whether broader structural changes, such as the decline of certain industries or increased job insecurity, are limiting opportunities for adults to learn through experience.
Percentage point change in the share of adults who learn by doing
Note: Adults aged 25-65 who reported learning by doing occurring at least once a month at current or most recent job. Cycle 2 data refer to 2023; data for Cycle 1 refer to 2012, except for Chile, Israel, Lithuania, New Zealand, and Singapore (2015) and Hungary (2018). See Box 1.3 for a note on comparison of data between Cycle 1 and Cycle 2. OECD is an unweighted average of all participating member countries. Results that are not statistically significant at the 5% level (p > 0.05) are shown in striped bars.
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2012, 2015, 2018, 2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
Drops in adult learning participation and in average skill proficiency go hand-in-hand
The relationship between job-related adult learning and skills development is complex, particularly where key information-processing skills such as literacy and numeracy are concerned. While participation in adult learning is generally associated with the maintenance and upgrading of skills, the extent of this impact depends on a number of factors, including the type, quality and intensity of learning, as well as broader individual and labour market conditions.
Literacy skills have stagnated or declined in many countries between survey cycles, while numeracy trends have been more mixed. These trends in skills are correlated with changes in adult participation. In particular, countries where literacy levels have fallen more sharply often show a corresponding fall in participation in adult learning (Figure 1.17). As ever, it is important to recognise that correlation does not imply causation.
There are several possible explanations for this relationship. One possibility is that declining participation in job-related adult learning limits the opportunities for adults to maintain and update their foundational skills, thereby contributing to skills deterioration over time. Another explanation could be that broader structural changes – such as demographic change – are simultaneously driving both lower participation in learning and weaker skills outcomes. As this relationship is complex, further research is required to explore and understand the dynamics influencing skill proficiency and adult learning at the aggregate level. This should include verification with other data sources, such as AES data.
These findings underline the need for policies that strengthen lifelong learning systems and ensure that adults – especially those with lower levels of information-processing skills – have access to meaningful and effective learning opportunities. As economies continue to evolve, maintaining and improving the skills of adults will be critical to the adaptability of the workforce, productivity and economic resilience.
Correlation between change in formal and non-formal participation and change in average literacy score
Note: Adults aged 25-65, formal and non-formal job-related learning. Cycle 2 data refer to 2023; data for Cycle 1 refer to 2012, except for Chile, Israel, Lithuania, New Zealand, and Singapore (2015) and Hungary (2018). See Box 1.3 for a note on comparison of data between Cycle 1 and Cycle 2. OECD is an unweighted average of all participating member countries. See note for Poland in the Reader’s Companion (OECD, 2024[2]).
Source: OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2012, 2015, 2018, 2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
The measurement of adult learning varies across international surveys, with differences in concepts, reference periods and survey designs affecting comparability. Three main sources for measuring adult learning across countries are the Survey of Adult Skills (PIAAC), the Adult Education Survey (AES) and the Labour Force Survey (LFS). While all three aim to measure participation in lifelong learning, methodological differences mean that reported participation rates and trends can vary considerably for individual countries.
The Survey of Adult Skills (PIAAC) measures formal and non-formal learning in the previous 12 months through its background questionnaire. In Cycle 1, non-formal learning was covered by several detailed questions, similar to the AES. In Cycle 2, this has been simplified to a single question, somewhat in line with the LFS, but potentially leading to lower reported participation rates. Typically, data is available every tenth year.
Adult Education Survey (AES) is a specialised adult learning survey, which provides the most detailed measurement of formal and non-formal learning in Europe, covering different types of training activities. It is conducted every six years, and, like PIAAC, it uses a 12-month reference period, making it the primary source of long-term trends in adult learning in the EU. Typically, data is available every sixth year. AES data show an increase in EU-27 participation over the last decade from 40% to 47% (not limited to job-related learning). As in PIAAC, the country that has seen the largest improvement is Ireland, but there have been breaks in time series.
Labour Force Survey (LFS) includes questions on participation in education and training, with the 12-month reference period introduced in 2022 to complement the AES. This data will now be available every second year. However, recent participation in the last 4 weeks remain the main LFS measure, which tends to underestimate engagement in learning compared to a 12-month measure. LFS participation trends have been relatively flat for the EU-27 over the past decade (10-11%), with a dip in the COVID-year 2020 (9%) and a notable uptick in the most recent years, 12% in 2022 and 13% in 2023. However, there has been a change in methodology in 2021, making comparisons difficult. Some countries have seen comparatively large increases in participation, most notably Estonia and Sweden.
Figure 1.18 compares the trends of these different surveys for those European countries that participate in all three surveys. It should be noted that comparisons are not straightforward due to different lengths of the time series, different numbers of cycles and breaks in the time series. Data points between data collection cycles are simple extrapolations for presentation purposes only.
Positioning of PIAAC and implications
Despite efforts to align definitions, methodological differences lead to systematic differences in reported participation rates and trends over time. As a result, LFS based 12-month participation rates are generally lower than AES based rates. Eurostat considers the AES to be the more accurate measure of participation levels, while the LFS is useful for tracking trends more frequently.
While PIAAC was aligned with the wording used in AES in Cycle 1, PIAAC Cycle 2 introduces a measurement approach that is closer to the LFS, raising concerns about a possible underestimation of non-formal learning in Cycle 2. This means that some of the decline in non-formal learning participation observed in PIAAC may be due to these differences in question wording. While PIAAC provides cross-country comparisons beyond Europe, its results should be interpreted alongside AES and LFS data to provide the most complete picture of trends in adult learning.
Share of adults participating in formal and non-formal learning, AES, LFS and PIAAC, %
Note: Adults who participated in learning activities in the 12 months prior to the survey. Unweighted average for Austria, Belgium/the Flemish Region of Belgium, Czechia, Denmark, Germany, Estonia, Finland, France, Hungary, Ireland, Italy, Lithuania, the Netherlands, Norway, Poland, Slovak Republic, Spain, Sweden.
Source: AES (2011, 2016, 2022); LFS (2022, 2024); OECD (n.d.[5]), Survey of Adult Skills (PIAAC) (2012, 2015, 2018, 2023) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html; data between survey cycles are interpolated. Underlying data are reported the accompanying Appendix Tables, available at https://www.oecd.org/en/publications/trends-in-adult-learning_ec0624a6-en/support-materials.html.
References
[3] Eurostat (2016), Classification of learning activities (CLA) manual : 2016 edition., Publications Office of the European Union, Luxembourg, https://doi.org/10.2785/874604.
[1] OECD (2024), Do Adults Have the Skills They Need to Thrive in a Changing World?: Survey of Adult Skills 2023, OECD Skills Studies, OECD Publishing, Paris, https://doi.org/10.1787/b263dc5d-en.
[2] OECD (2024), Survey of Adult Skills – Reader’s Companion: 2023, OECD Skills Studies, OECD Publishing, Paris, https://doi.org/10.1787/3639d1e2-en.
[9] OECD (2023), Education at a Glance 2023: OECD Indicators, OECD Publishing, Paris, https://doi.org/10.1787/e13bef63-en.
[4] OECD (2023), Flexible Adult Learning Provision: What it is, why it matters and how to make it work, OECD, Paris, https://www.oecd.org/content/dam/oecd/en/topics/policy-sub-issues/adult-learning/booklet-flexibility-2023.pdf/_jcr_content/renditions/original./booklet-flexibility-2023.pdf.
[7] OECD (2021), Training in Enterprises: New Evidence from 100 Case Studies, Getting Skills Right, OECD Publishing, Paris, https://doi.org/10.1787/7d63d210-en.
[8] OECD (2020), “The potential of online learning for adults: Early lessons from the COVID-19 crisis”, OECD Policy Responses to Coronavirus (COVID-19), OECD Publishing, Paris, https://doi.org/10.1787/ee040002-en.
[5] OECD (n.d.), Survey of Adult Skills (PIAAC) Database, http://www.oecd.org/en/about/programmes/piaac/piaac-data.html (accessed on 11 June 2025).
[6] OECD (Forthcoming), Technical Report. 2023 Survey of Adult Skills.
← 1. It should be noted that this group may include a significant proportion of young adults who are still completing their initial education in certain countries. On average, the average age of first-time tertiary graduates across OECD countries is 20.26. However, there are notable differences between countries, ranging from 22 in Japan to 29 in Latvia. However, this report does not statistically distinguish between initial tertiary education and adult learning for individuals aged 25 and over. (OECD, 2023[9])
← 2. This is the average of OECD member countries that participated in the 2023 Survey of Adult Skills.
← 3. A minor changed occurred in the measurement of formal adult learning across cycles. Cycle 1 included a direct question if adults ‘have studied for a formal qualification in the last 12 months’, a question that was not included in Cycle 2. However, this question was mostly redundant and was covered already elsewhere through current participation in formal education and time passed since prior participation in formal education.