The role of self-directed learning while supporting NEET-youth: theoretical model based on systematic literature review

ABSTRACT Self-directed learning as a key component of lifelong learning has become increasingly important in a rapidly changing society. SDL competencies support continuous personal development and coping with change. At the same time, there is a significant number of young people in society who do not participate in working life, education or training (NEET-youth) and are characterized by low levels of motivation and skills. Therefore, the question arises how to operationalize the concept of SDL for NEET-youth, and how to measure their SDL competencies. This literature review is based on the analysis of 28 articles. The concept, dimensions, and assessment methods of SDL were analysed. The results were synthesized considering the characteristics of NEET-youth. As a result, a theoretical model was developed that describes the content of SDL considering the characteristics and needs of NEET-youth. Such theoretical modelling is important for developing appropriate assessment and intervention tools for the target group.


Introduction
Society expects people to be self-driven and independent when managing the challenges in their life and achieving goals, personal as well as societal.At a time when labour markets and learning opportunities enable greater flexibility, it is assumed that people should have more autonomy and better skills of self-direction (Kovalenko & Mortelmans, 2016).Missing the necessary competencies entails greater numbers of young people who drop out of education, do not study or work (NEETyouth).
Empowering society through education must also pay attention to the SDL competencies of the NEET-youth and support them to bring them back into the learning process.Because assessment of learning needs, resources and planning for learning are part of the SDL process (Knowles, 1975), higher SDL skills not only support informal learning but can lead a person back to formal educational.In this paper, learning is defined according to Ambrose et al. (2010) as a process involving changes in knowledge, beliefs, behaviours, or attitudes.Since the definition of the NEET-youth is used to describe the situation when a person is not in employment, education or training, the focus of this article is primarily on supporting young people to return to education and continue learning in the education system.Paabort et al. (2023) have highlighted the need to explore how to prevent or exit NEET-status.
Previous research reveals a number of socio-demographic characteristics of early school leavers, but does not consider their learning skills or readiness to return to education and manage their own learning throughout their lives.Ellena et al. (2021) pointed out that soft skills are important to fully CONTACT Kerli Kõiv kerli.koiv@ut.eeunderstand the phenomenon of NEET-youth, but few researchers have investigated it.Data on NEETyouth are often limited to demographics, and more qualitative studies are needed to investigate the multiplicity of youth experiences and influencing factors (Rahmani & Groot, 2023).Mawn et al. (2017) highlight that restrictions in the amount and quality of evidence about interventions leave the researchers in a situation where the best practice for changing the lives and prospects of NEET-youth is unclear.There is a need to adopt high-quality evidence methodologies to determine what works best for them.Therefore, the question arises of how to understand SDL for people not in education and employment, and how to measure their SDL competences.This study is a step forward in opening up the problem set of NEET-youth from the perspective of learning and education.
In order to focus on the SDL concept in the context of NEET-youth, we set out to analyse the dimensions, assessment methods and tools of SDL from the perspective of NEET-youth.As a result of the study, a theoretical model was developed that describes the content of SDL considering the characteristics and needs of NEET-youth.Such theoretical modelling is important for developing appropriate assessment and intervention tools related to the SDL competences for the target group.

Self-directed learning
SDL is situated at the macro level, which means that it concerns a learning trajectory as a whole; a self-directed learner is able to decide what needs to be learned next and how their learning is best accomplished (Jossberger et al., 2010).As a fundamental competence for preparing persons for adult life, SDL empowers adults to adapt to fluid and complex social contextual changes (Bolhuis, 2003;Morris, 2019).According to the most quoted definition by Knowles (1975), SDL is a process in which individuals take the initiative, with or without the help of others, in diagnosing their learning needs, formulating learning goals, identifying human and material resources for learning, choosing and implementing appropriate learning strategies, and evaluating learning outcomes.A self-directed learner is aware of the constraints on their efforts to learn, has access to alternative perspectives for understanding their situation and for giving meaning and direction to their life, has acquired sensitivity and competence in social interactions, and has skills and competencies required to master the productive tasks (Kasworm, 1983).SDL skills as non-cognitive skills predict later-life outcomes and they have long-term effects on education (Farrington et al., 2012).People with sufficient SDL skills are more satisfied with their life and have a more purposed direction regarding their future aspirations (Edmondson et al., 2012).Therefore, SDL competencies are crucial for continuing the lifelong learning process and ensuring competitiveness in the labour market.Knowles (1975) highlighted a number of different important competencies in the SDL process including understanding the self-learner concept, learner attitudes, as well as the skills needed to implement the learning process.According to Brockett and Hiemstra (1991), SDL refers to an instructional method and personal characteristics in which personal responsibility is a starting point and individuals need to be the owners of their thoughts and actions, and have control over their learning process.Improving SDL competencies is one of the solutions that brings young people back into education and support their participation in lifelong learning in order to be resilient to societal change.Morris (2019) emphasizes that when interpreting SDL as a personal process, it is important to remember that human learning and development does not occur in a social or contextual vacuum.Therefore, it is important to consider what situation a person is in his personal life.

NEET-youth
Dropping out of school and interrupting education is one of the most alarming situations in society.Young people who are not in education, employment or training are called NEET-youth (Furlong, 2006).NEET as a policy discourse is used across the world.In 2021, 13.1% of the European Union population aged 15-29 were NEET-youth.Although not all young people who could be classified as 'NEET' are necessarily at risk of social exclusion, nor is their lack of work, training or education necessarily problematic or linked to other risks or negative orientations (Yates & Payne, 2006), education is essential factor and has the greatest impact on the probability of becoming a NEET (Mascherini, 2019;Rahmani & Groot, 2023).Mascherini (2019) has pointed out two principal risk factors relating to NEET-youth: educational disadvantage is associated with social factors such as the family, school, and personal characteristics and disaffection concerns the attitudes young people have towards education and schooling specifically.Young people who discontinue their studies in higher education for family or for health reasons or because of the cost of education have a higher probability of becoming NEET (Rocca et al., 2022).Since the general education level of NEET-youth is generally low (Eurostat, 2022) and there are no specific studies on NEET subgroups, the NEET target group as a whole should first be considered.
Despite the heterogeneity of the target group, the studies have found that the young people who leave education and training prematurely are bound to lack skills and qualifications, and they face a higher risk of unemployment, social exclusion and poverty (Konle-Seidl, 2021).Low skill level and low educational attainments significantly increase the probability of reporting long-term NEETstatus (Barth et al., 2021;Jongbloed & Gireth, 2021).Young people who are not in education or employment may have low self-esteem and they more frequently have fewer resources than their peers (Stea et al., 2019).Loss of interest in learning (McDermott et al., 2019), external regulations, lack of social support (Vasalampi et al., 2018), and relationships with adults (Duffy & Elwood, 2013) put young people in a situation where they leave the education system but do not enter working life.Young people who discontinue their studies for family reasons (incl.parents' education and attitudes towards education) or for health reasons or because of the cost of education have a higher probability of becoming NEET (Rocca et al, 2021).Overcoming life's obstacles and continuing personal development requires a combination of various skills and attributes.

Competencies of NEET-youth
Attitudes as well as skills are important when planning and implementing learning plans.Low skill level and low educational attainments significantly increase the probability of reporting long-term NEET-status (Jongbloed & Gireth, 2021).In addition, the NEET condition predicts a negative view of the future, a lack of orientation towards objectives and difficulties in the use of planning strategies (Parolaì & Dons, 2019).Vugt et al. (2022) have discussed that young people with low general skills are at higher risk of dropping out of education and this may be because they have difficulty acquiring and developing future skills due to their experience that has led them not to believe in success and to have future vision.Negative learning experiences or failure in education in general affect the peoples' readiness to participate in lifelong learning (Brockett & Hiemstra, 1991).Because NEET-youth as a target group are mostly characterized by a low level of education (Eurostat, 2022), a lack of responsibility (Helemäe, 2018), insufficient skills, a lack of capacity and motivation, and a non-optimistic feeling about their chances to get ahead in life (Goldman-Mellor et al., 2016), then in order to increase the participation of NEETyouth in lifelong learning, targeted support activities are crucial.Hamlin (2022) also highlights the need to change the habits to be the self-directed learner.
NEET-status may be also a conscious choice for some people and they participate in the learning process independently, but this has been little researched so far.Morris (2019) pointed out that the personal characteristics required for SDL have been less researched and the assumption that all people who undertake SDL are competent self-directed learners should be avoided.This situation raises the need to study and develop competencies that support young people in their development process, with educational choices and coping with challenges.

Support for NEET-youth
While the probability of becoming NEET-youth has been reported to decrease in correlation with an increase in educational level (Eurofound, 2016), education is crucial to avoid early dropout.By developing new skills that support learning, it is possible to positively influence young people's goal-setting, coping with difficulties, and the development of their future vision.Gunawardena and Stich (2021) have highlighted young adulthood as a period of life associated with dependence and independence, decreased parental support, and increased need for support from other adults as parents.Society should be ready to provide interventions and support for the personal development of young people.The focus of the services aimed at NEETs has not yet been clearly defined, and the development of young people's skills is not approached holistically (Kõiv et al., 2022).
Supporting young people must be seen from the perspective of positive development, where the aim is to understanding, educating, and engaging youth in productive activities rather than at correcting, curing, or treating them for maladaptive tendencies or disabilities (Damon, 2004).Positive youth development theory has highlighted the growing belief that strengthening support for personal development, reinforcement of social networks and enhancement of social participation may be reducing risks and problems and preventing the need for social care in young people's lives (Catalano et al., 2004).
Based on the concept of SDL, the skills of SDL help NEET-youth, similar to peers, to see a long-term perspective in their own development, analyze the resources, set the learning strategy and realize it, rather than get trapped in the obstacles.The role of intrinsic motivation in initiating activities is very important (Ryan & Deci, 2000), and therefore it is crucial that educational choices and support are based on the young person's own intrinsic motivation and vision, and they have the competencies they need to plan their own learning trajectory.Yates and Payne (2006) pointed out that there is the urgent need for an approach to understanding young people and targeting intensive support that takes into account the characteristics, situations and difficulties that they actually experience rather than an over-riding focus on their (NEET) status.Therefore, the focus on supporting the coping skills of NEET-youth should not be seen only in terms of resolving social problems but also in strengthening the young person's own life management competencies.

The aim of the study
Research on different interventions has highlighted that NEET-youth may have complex needs requiring a targeted psychological approach, including counselling, mentoring and motivational interviews (Oliver et al., 2014).However, the relative effectiveness of the interventions is not known and the interventions tend to adopt a pragmatic approach (e.g.classroom and work experience) rather than targeting potentially important psychological barriers to engagement (e.g.enhancing confidence, reducing distress) (Mawn et al., 2017;Oliver et al., 2014).Although it is generally known that the certain learning and coping skills protect young people from NEET-status, Barth et al. (2021) highlighted that there is a lack of research on how these skills can be developed.There is need to collect and better understand non-cognitive skills (Heisig et al., 2019) and use self-efficacy measures that are more focused on career development process, such as planning and decision-making (Cardoso & Moreira, 2009).
Even though there is considerable research on the importance and impact of SDL skills, very little is currently known about self-direction skills of NEET-youth, the skills they might need to return to the learning path and the measures that have enabled them to facilitate these skills.Therefore, a systematic literature review was conducted to critically examine the interpretations of the construct of SDL, its dimensions, and the methods of measurement.The findings received from the systematic analysis of SDL were synthesized with knowledge we have about the learning needs of NEET-youth, their learning practices and the obstacles they face on their learning path.
This paper aims to operationalize the concept of SDL in the context of NEET-youth, presenting a comprehensive overview of its dimensions, assessment methods and tools.Synthesizing the results of a systematic literature analysis and earlier findings on NEET-youth and their barriers to learning, the theoretical model is constructed to indicate ways to support the learning ability of NEET-youth through SDL skills.
Proceeding from the aim of the study the following research questions were formulated: (1) What is the comprehensive definition of SDL for NEET-youth?
(2) Which SDL dimensions are assessed and how?
(3) Which SDL factors are related to the development of the SDL competencies of NEET-youth?

Search procedure
The search for articles for a systematic literature review was conducted in December 2020.The search targeted the studies that define the construct and dimensions of SDL and report measuring.
The selection process for the systematic literature analysis was based on the PRISMA framework (Moher et al., 2009) (see Figure 1).The initial search for articles was carried out in the digital EBSCO databases Academic Search Complete, APA PsycInfo and ERIC, as the most valuable and comprehensive scholarly, multi- disciplinary full-text databases focusing on behavioural science and educational research, and which are important considering the focus of this study.As the aim of the research was to understand the concept of SDL and its impact, the advanced search function and the following search terms were used to identify an initial pool of articles: 'self-directed learn*' AND assess* OR evaluat* OR measur×.As the earliest studies on SDL go back to the middle of the 20th century, the search was constrained to the period 1950-2020.Additionally, full text, and English as the language of the articles were applied in the search procedure.Young people with NEET-status in Europe are aged 15-29 (Eurofound, 2022), and therefore, the studies that target 15-year-olds or older were of interest to the study.There was no upper age limit for the choice of the target group, as the background of the target groups in the studies may be useful from a research perspective, and the upper age limit for NEET-youth in the world may also differ.
The initial search of the three EBSCO databases for relevant articles resulted in identifying 1,177 articles.Then the search was limited to the following age groups: adulthood (18 yrs and older), young adulthood (18-29 yrs) and adolescence (13-17 yrs) and 58 duplicates were removed from the remaining 315 records.In the first round of screening, the eligibility of the titles of 257 records were estimated by two researchers.The inclusion criterion was a clearly visible association of SDL and its measurement in the title.The articles with words like lifelong learning, self-monitoring, motivation or effort to learn, self-directedness, self-regulated learning, individual learning, academic success in the titles were also included.The inter-rater reliability of the title screening resulted in 93%.The secondlevel screening involved abstracts − 73 abstracts selected from the pool of 257 articles were analysed and estimated by two researchers.The inter-rater reliability resulted in 86.6%.The screening of abstracts left us with 49 studies.
As the next step, the full text of each identified study was downloaded.During this step, full text screening was performed to confirm the article's eligibility.The texts were assessed based on one or more of the following criteria: 1) concept and dimensions of SDL; 2) SDL measurement tools.The following exclusion criteria appeared: low or unclear connection with SDL; general feedback or assessment in education; focus on school, curriculum or subject evaluation, teaching or mentoring development; health conditions development.As a result, 28 articles that focused on measuring selfdirected learning and its factors formed the final pool for subsequent analysis.

Data analysis
All the collected data was compiled systematically using MS Excel.The following data was included: (a) descriptive information about the study (i.e.title, authors, year of publication, journal, main domain and the sample; (b) data needed for answering RQs -theory, used definition, measurement tool, dimensions and characteristics of SDL.For validation purposes, two authors analysed the full texts of 10 studies using the given table and compared the extracted data.A consensus was reached on the minor differences which occurred.

Methodological qualities
The aim of the current review was to operationalize the concept of SDL in the context of NEET-youth presenting a comprehensive overview of its dimensions, assessment methods and tools.Consequently, all 28 articles addressed the SDL competence, highlighting the theoretical basis and 25 of them also measurement tools.The used definition and measurement tools were categorized according to the data in the articles.
Most of the articles described the SDL measurement process, in which the sample, the measurement tool and its components were important and key to the present study.Two of the articles presented an analysis based on SDL theories and a systematic review of the literature, and one article was a validity study of three different measurement tools.
These articles added valuable material in addressing the definition of SDL and the measurement tools for this study.

Study components
For each article, the theories and definitions of SDL were identified and the main characteristics for each concept were generated (N = 57).The characteristics that occurred five or more times (N = 13) were analysed to define their substantive content.The nature of the main characteristics of SDL was analysed on the basis of the articles in which they appeared and a description of the characteristic was given.Based on the comparison of the descriptions, the most binding dimension of the characteristic descriptions was created.The dimensions were linked to show the connections and based on their synthesis a theoretical model of SDL was created.All 57 characteristics were divided according to the dimensions based on its description and the correspondence of the characteristics to it.None of the articles targeted NEET-youth.The collected data had to be interpreted by comparing the existing general data on NEET-youth.Based on the knowledge of NEET-youth, the characteristics that most characterize the target group were found and related to a specific SDL dimension.The results were synthesized and used to create an SDL model and definition of NEETyouth.
Measuring instruments (N = 16) were also mapped, highlighting the used factors (N = 42) and those with similar content were combined into common factors (N = 18), which in turn were distributed among the previously created dimensions (5).Relying on the theoretical framework and the dimensions most suitable for the characteristics of NEET-youth, the corresponding dimensions of the measuring instruments were found and application recommendations were created on this basis.

Defining self-directed learning for NEET-youth
In order to answer the first research question on the definition of SDL suitable in the NEET-youth context, 28 articles on the assessment of young people's SDL were analysed.The analysis revealed two main universal definitions describing SDL -by Knowles (1975) and Brockett (1983).The other definitions cited in the articles originated from Garrison (1997), and Brockett and Hiemstra (1991), or were formulated by the authors themselves (e.g.P. L. Guglielmino & Roberts, 1992;Raemdonck et al., 2014).
The definitions from the analysed articles are used universally for all target groups and are not specified for any specific group of people, those who have dropped out of education among them.According to the focuses of the articles, it is possible to identify that SDL is seen as both an instructional method and a personality characteristic.This coincides with the conceptual framework of the PRO-model by Brockett and Hiemstra (1991), according to which external and internal characteristics should match, so that the teaching-learning situation fits the needs and desires of the learner and the social context in which the learning takes place.Therefore, it can be concluded that SDL is theoretically addressed at the process and personal level, which are interrelated.

Characteristics and dimensions of SDL
In order to find out what dimensions are present in the definitions of SDL and what are particularly important for NEET-youth, the definitions from the articles were analysed and the topical characteristics of a self-directed learner and SDL were extracted.The analysis revealed 13 most common characteristics, which operate within the basic concept of SDL.All characteristics were grouped into dimensions.The analysis provided us with five different dimensions: process preconditions, personal preconditions, elements of the process, developing skills, and tools (see Figure 2).Process preconditions as the concept of the process combines characteristics that highlight the main direction of the process (e.g.being personal and based on learning needs).The characteristics that describe the learner's attitudes and characteristics are concentrated in the dimension, personal preconditions.The dimension of developing skills brings together generic skills and abilities to do something.Elements of the process describe the activities of the process and tools are the methods by which these activities are carried out.Tools are defined here as instruments or interactions used during the SDL process.
The dimensions identified are in line with most of the basic concepts.Based on the two most widely used SDL models (Brockett, 1983;Knowles, 1975), SDL assumes that a human being grows in capacity to be self-directing as an essential component of maturing, then the change in personal preconditions can be considered the goal of the process (Knowles, 1975).Furthermore, the starting point of Brockett and Hiemstra's PRO-model (1991) is personal responsibility, which can be taken as a personal change in the process for those who are out of education.Due to the above, the goal dimension should be added to the full concept of SDL, as both personal preconditions and skill characteristics may change the achievement of the process goal.
The dimensions distinguished in the studies can be divided into person-and process-related, where the dimensions personal preconditions, developing skills and goals are person-related and process preconditions, elements of the process and tools are process-oriented.The SDL process, the purpose of which can be explained in terms of results, can be described as a personal factor in the way that a precondition is an important factor in entering the learning process and process elements, tools and skills are important in the process.
The listed dimensions and characteristics are universal and describe self-directed learning/learner in the most general sense, without regard to the differences that may exist for the target groups.In the case of characteristics, it is important to find their connection with the main dimensions and on this basis to find the most important characteristics within each dimension that consider the specifics of NEET-youth.To support the SDL of NEET-youth, it is necessary to link the basic SDL model to the specificities of NEET-youth.Looking at NEET-youth, the (in)ability to self-direct their learning must be considered due to their low level of skills, lack of capacity, motivation (Goldman-Mellor et al., 2016), responsibility (Helemäe, 2018) and social capital (Stea et al., 2019) and the consequent need to support them.

Definition of NEET-youth SDL
Based on the knowledge that the skill levels of NEET-youth are generally low (Goldman-Mellor et al., 2016) and that they mostly need external support (Oliver et al., 2014) because of their limited social network and/or resources (Stea et al., 2019), and due to the NEET-status they are already outside the traditional educational space, there is a need to pay attention to certain characteristics and dimensions in the SDL definitions in order to find the most appropriate to describe their SDL process.Therefore, the definitions, which include the support component, are the most appropriate to adopt for NEET-youth.
NEET-youth are characterized by a low level of education, and therefore they cannot be expected to have primary readiness for learning.Understanding one's personal learning needs will be a prerequisite for starting the SDL process.Given that young people tend to drop out of school because of a lack of structural and intrinsic motivation (Pohl & Walther, 2007;Ryan & Deci, 2000) and low levels of soft skills (Goldman-Mellor et al., 2016), such as behavioural competencies, then the process of supporting and developing their SDL skills must focus precisely on those dimensions that are related to attitudes and skills.NEET-youth are characterized by a negative view of the future (Parolaì & Dons, 2019) and low intrinsic motivation (Ryan & Deci, 2000); therefore, the existence of a positive view of the future and interest in the world is an important result in supporting NEET-youth SDL competencies.By dividing the 57 characteristics found between the created dimensions, it was possible to find among them characteristics that best meet the needs of NEET-youth.The following characteristics found in the precondition dimension are more suitable in this case for NEET-youth: curiosity, future orientation, desire for learning, independence, motivation, attitude, initiative.This is complemented by the development of specific skills that enables the young person to manage the learning process skilfully.
Regarding young people, their difficulties in using planning strategies (Parolaì & Dons, 2019) and taking responsibility (Helemäe, 2018) are highlighted, which rises the need for developing young people's management skills.The characteristics and the skills dimension that support process management are: basic study skills, problem-solving skills, self-evaluation, self-management, planning skills, self-efficacy, and self-determination.These are the aspects that need to be considered when supporting NEET-youth SDL.SDL for NEET-youth must be based on a target-group approach in order to ensure a return to education in general, moving forward with higher learning goals, and ensuring a lifelong learning path.
According to the SDL model (see Figure 2), the dimensions and characteristics highlighted, and the features that characterize NEET-youth (see Figure 3), it can be specified that the relevant preconditions and goals are those with a different emphasis from the traditional SDL concept while process elements may be similar.
Based on the main significant dimensions and characteristics identified as a result of the analysis and the nature and needs of NEET-youth, the following definition of SDL for NEET-youth is formulated: Self-directed learning for NEET-youth is a supported process during which a person's attitude toward learning improves, and the subject develops initiative, independence and abilities in shaping their educational path with a positive outlook on the future.The created definition helps shape the understanding of the concept of SDL win the context of NEET-youth and guide support processes for measuring and developing the SDL skills of NEET-youth.

Assessing the dimensions of SDL
In order to support learners' SDL effectively, there is a need to assess their SDL competence.In previous practice, different methods and tools have been used to measure SDL skills.Based on the 28 articles analysed, 16 different evaluation instruments in the form of self-report questionnaires and an interview were identified, which were used alone or in combination with other instruments (see Table 1).
Depending on the instrument, the number of items varied.Measurement of the SDL process and personal characteristics differs widely on the basis of the analysed articles and there is no single definitive approach.Based on the above, it can be pointed out that there are several self-report instruments for measuring learners' SDL, depending on the specific focus or target group for which the measurement is planned.
Based on the above analysis, both internal and external factors (Brockett & Hiemstra, 1991) -personal and structural -are important in the development of SDL competence.The analysis of the measurement factors revealed five main dimensions -attitudes, skills, characteristics, process elements and tools.Each dimension consists of different measurable factors.The most common factors in the SDL measurement were assessing the need for learning (Cheng et al., 2010;Harvey et al., 2003), assessment of performance (Kicken et al., 2009;Suh et al., 2015;Williams & Brown, 2013), love and motivation for learning (Chang, 2006;Cheng et al., 2010;

Measurement instrument
Author(s) who have used this instrument SDLRS Self-Directed Learning Readiness Scale (L.M. Guglielmino, 1977) P. L. Guglielmino and Roberts (1992); (Dynan et al., 2008;Hoban et al., 2005;Lai, 2011); Joo et al., 2013;Durr et al. (1996); (Harvey et al., 2003;Lounsbury et al., 2009 Hoban et al., 2005;Lai, 2011), openness to learning opportunities (Chang, 2006;Hoban et al., 2005;Nothnagle et al., 2011;Waldrip et al., 2014;Williams & Brown, 2013), and using a range of resources (Cheng et al., 2010;Harvey et al., 2003;Kicken et al., 2009;Suh et al., 2015).The factors used in the instruments can be divided into process factors, subdivided into process elements (self-assessment; identify the learning needs, strategy, planning, implementing), tools (resources, interpersonal communication, teaching-learning transactions, active learning), and personal factors, subdivided into skills (process-related skills, learning behavior), characteristics (personal characteristics), and attitudes (self-concept, beliefs, motivation, learning orientation).Nothnagle et al. (2011) added the factor of developmental progress in learning, which can be considered as similar to goal, and includes change in attitudes and skills.(see Appendix 1) According to the results of the current analysis, it can be concluded that the main dimensions in measuring SDL are attitude, skills and characteristics, and dimensions related to the process elements and learning activities as tools.In measuring and developing the SDL competencies of NEETyouth, it is important to find the factors that are most relevant to them.

Factors relating to the development of NEET-youth SDL competencies
In order to answer the third research question, knowledge about NEET-youth is merged with knowledge about SDL received from the current literature analysis.Regarding the factors used in the measurement instruments, it was necessary to consider that the existing instruments were adapted to consider the cultural (Suh et al., 2015) or other target group-based contexts (Joo et al., 2013) but were not related to NEET-youth.The measurements set out to find additional links between SDL and other aspects, such as emotional intelligence (Zhoc & Chen, 2016), online learning context (Lai, 2011), career satisfaction (Joo et al., 2013), and others.Only the combined instrument by Lounsbury et al. (2009) investigated the relationships between personal characteristics and the risk of dropping out of school, while all other studies were related to the assessment of SDL in people studying or working.
Based on the definition formulated above, attitudes and skills play a crucial role in the development of NEET-youth SDL competencies.Considering the low level of motivation and skills of NEETyouth and the conclusion that NEET-youth SDL development should focus on changing attitudes and skills, all factors under these dimensions have a crucial impact on NEET-youth SDL.It is important to note that in the theoretical approaches of SDL less attention is paid to personal characteristics.In some measurement processes additional scales of personal characteristics in combination with SDL scales are used (e.g. the scale of emotional intelligence (Zhoc & Chen, 2016), the big five model (Lounsbury et al., 2009).Considering the potential for NEET-youth to be less motivated to learn (Vasalampi et al., 2018) and the significant impact of motivation for initiating activities (Ryan & Deci, 2000), the characteristics that affect motivation should be seen as personal characteristics.
People who are not in education or work have so far received little attention in the context of SDL research, and the factors relevant to their profile have not been investigated.In the case of NEETyouth, personal factors are crucial, since their role as preconditions for the SDL process is very important.Elements and tools of the SDL process cannot always be considered as factors, because their participation in the learning process is uncertain.A meta-analytic review of students' SDL by Boyer et al. (2014) suggests factors of internal locus of control, motivation, support, and self-efficacy as important in increasing students' willingness to direct their learning process.Comparing these factors with NEET-youth, due to non-participation in education, lack of knowledge of their learning process and heterogeneity of the group, the personal factors should be evaluated more precisely.Factors of SDL that should be considered for NEET-youth are process-related skills, learning behaviour, personal characteristics, self-concept, beliefs, motivation, and learning orientation.
SDL is seen as supported process for NEET-youth, and the elements of the process have an important impact on the development of SDL competencies in youth, but the personal characteristics of the young person should also be considered in the measurement of SDL competencies.

Limitations
The analysed articles only concerned about the self-directed learning skills of the studying and working people and had no connection with NEET-youth.Since there is little scientific evidence on the self-directed learning skills of NEET-youth, the theoretical model and definition created is based on the limited information available.In this context, there is a need to increase research on the skill levels and characteristics of young people who have dropped out of school, and to improve the model based on this.
NEET-youth are mainly addressed as a vulnerable target group, but quite heterogeneous: not all young people with NEET-status are in a vulnerable status.It is argued that to effectively represent vulnerable young people, we need to either use a set of definitions that is narrower than NEET-youth, or adopt a much broader definition that provides the basis for more comprehensive interventions (Furlong, 2006).Criticism about the name of NEET-youth is also developed by Hayward and Williams (2011), indicating that the name of NEET-youth can also be treated as a statistical residual category.
In the context of this study, the interest was to consider SDL in the context of those young people who have dropped out from education, but are not working, either.Then, the use of the term NEETyouth as a whole was appropriate.At the same time, further research, including the continuation of SDL research, may provide an opportunity to define narrower subgroups within the target group of NEET youth.

Conclusion
The present study is based on the assumption that the general educational level of NEET-youth is low (Eurostat, 2022) and they do not participate in education (Furlong, 2006).Since the categories of NEET-youth have not been studied so far, the NEET-youth is not subcategorized in this study either.This study provides the concept of how SDL should be viewed from the perspective of NEET-youth and guides future work to further extend existing learning theories by adapting them for people out of the active formal or non-formal education.The current study highlights SDL skills as essential to be lifelong learner and these skills should be developed also by young people who are early leavers from the education.
The present analysis revealed that no specific approaches have been applied to the definition or measurement of SDL for NEET-youth or other target groups not involved in education or employment.As the approaches applied are related to participation in the education, then this is a fact that cannot be considered for NEET-youth.In the case of NEET-youth, the SDL process must be seen as a process of change that supports the development of positive attitudes and the development of the skills needed to drive the SDL process.
In developing SDL competencies in NEET-youth, it is necessary to pay attention to the weaknesses that are most dominant for NEET-youth, as well as to implementing the basic concept of SDL as a whole.By considering the SDL factors specific to NEET-youth, it is possible to target them with more effective support.For NEET-youth, personality factors are most crucial.Since the studies conducted so far on NEET-youth are predominantly about their socio-demographic characteristics and general policies related to the general target group, the approaches are needed to deal with the support processes from the perspective of the individual skills of the young person and the continuation of the educational path.
As a practical contribution, this work enables social workers, youth workers and educational policy makers, researchers and learning communities to develop interventions to maximize the sustainability of youth support and increase youth participation in education.The study highlights gaps in the existing research literature on NEET-youth's SDL skills and how to support them, making it a good guide for future researchers.The model can also be used for young people high risk of NEET-status.As Yates and Payne (2006) highlight, there are many different situations that young people experience within the NEET category, all of which need to be taken into account when working with them.There are also young people who are not NEET but may be in greater need of intervention and support than some of those who are.Therefore, reintegration aimed at those who have already dropped out of the education and training system is also useful as a preventive strategy to reduce the probability of dropping out later.
Developing instruments with considerable construct and content validity is important, and further studies should explore the possibilities of trace methodologies that open new perspectives for understanding and assessing SDL (Saks & Leijen, 2014).Previous practices in the measurement of SDL have not been based on the fact that a person may not be participating in learning activities or work.Therefore, it is necessary to take this into account when using SDL measurement instruments.Given that the structure of existing measurement instruments presuppose the participation in the educational or employment process, the creation of an additional instrument for measuring the SDL of NEET-youth should be considered.

Figure 1 .
Figure 1.The process of selecting studies for analysis.

Figure 2 .
Figure 2. The model of SDL dimensions and characteristics based on systematic.literature analysis.

Figure 3 .
Figure 3.The model of SDL dimensions and characteristics for NEET-youth.