First, the review presents an assessment of character strengths in adults in which the Values-in-Action Inventory of Strengths (VIA-IS) is the most representative (Arbenz et al., 2023; McGrath, 2025; Peterson and Seligman, 2004; Ruch et al., 2010). The scale puts forward conceptually organized 6 virtues and 24 character strengths (Figure 1). For example, character strengths such as hope, zest, and perseverance are positively associated with life satisfaction but negatively associated with depression, anxiety, and stress (Feraco et al., 2022; Ruch et al., 2014). While the VIA-IS consists of 240 items, short versions include the Character Strengths Rating Form (Ruch et al., 2014) and Character Strengths Test 24 (Shimai and Urata, 2023), which consists of only 24 items—one-tenth of the VIA-IS.

We then present the assessment of character strengths for children and adolescents. While the abovementioned measures were developed for adults, the VIA-IS for Youth (VIA-Youth; Park and Peterson, 2006) and its revised version (VIA-Youth-Revised [VIA-Y-R]; Jermann and McGrath, 2024) were developed for children and adolescents aged between 8 and17 years (Table 1). The VIA-Youth consists of 198 items, while the VIA-Y-R consists of 98 items. For example, character strengths such as gratitude, zest, and love of learning were positively associated with school-related satisfaction, academic self-efficacy, and positive classroom behavior among children and adolescents aged 10–14 years (Weber and Ruch, 2012).

Alternatively, Govindji and Linley (2007) pointed out the importance of focusing on a more general sense that is not limited to specific character strengths. Thus, they developed the Strengths Knowledge Scale (SKS) to measure awareness of having strengths and the Strengths Use Scale (SUS) to measure the use of strengths. These scales were initially developed for adults (Govindji and Linley, 2007; Takahashi and Morimoto, 2015; Wood et al., 2011), but versions for children and adolescents with age-appropriate language were eventually created (Oguni and Otake, 2017). The SKS and SKS for Children (SKS-C) consist of eight items each, while the SUS and SUS for Children (SUS-C) consist of 14 items each (Table 1). For example, strength knowledge and strength use among children and adolescents aged 8–18 years were positively associated with physical health and subjective wellbeing and negatively associated with depression and stress (Duan et al., 2018; Lai et al., 2018; Oguni and Otake, 2017). Additionally, strength knowledge and strength use in children and adolescents aged 11–18 years were positively associated with school belonging, academic motivation, and grade point average (Arslan et al., 2023; Duan et al., 2018).

However, the large number of items in these scales presents several practical challenges. The first issue is the burden for children and adolescents in terms of responding to a large number of items. They exhibit difficulty in maintaining concentration, while the response time is lengthy (Galesic and Bosnjak, 2009; Rolstad et al., 2011). Consequently, the large number of items reduces the quality of the data and negatively affects the reliability of the results. Importantly, overburdening children and adolescents raises ethical concerns. The second issue pertains to schools' reluctance to cooperate with research given that curriculum overload is currently an issue in many countries and regions (Majoni, 2017; Organization for Economic Co-operation and Development, 2020). Schools in countries and regions with curriculum overload are typically reluctant to participate in surveys that utilize scales with a large number of items. Even if schools are willing to cooperate, administering this type of survey may be difficult due to numerous school activities. Additionally, schools that are not accustomed to participating in research may be reluctant to adopt such a scale and may only agree to participate in an infrequent survey that includes scales with a few items. The third is the overall time burden of the research. For example, the SKS-C and SUS-C have fewer items than the VIA-Youth and the VIA-Youth-R. However, using as few items as possible for each scale is preferable, because surveys and intervention research use multiple indicators and tasks. In fact, surveys in educational settings require scales with fewer items to minimize the burden on children and adolescents and reduce survey time (Ahlen et al., 2018; Ravens-Sieberer et al., 2010).

To conduct basic research and educational practices on character strengths in children and adolescents, developing short scales that enable quick and efficient data collection while minimizing the burden on these groups is necessary. For example, Oguni et al. (2025) aimed to develop a short version of the SKS-C (SSKS-C) and the SUS-C (SSUS-C) using item response theory. Based on discrimination, difficulty, and test information, they developed the SSKS-C and the SSUS-C, which consist of one factor and two items, respectively (Table 1). The SSKS-C and SSUS-C directly reflect the core definitions of strength knowledge and strength use, capturing them concisely without including unnecessary elements (Oguni et al., 2025). Despite the significant reduction in the number of items, both short versions have sufficient measurement accuracy, equivalent to that of the full versions. Oguni et al. (2025) also tested the reliability and validity of the SSKS-C and SSUS-C. As a result, they demonstrated that the SSKS-C and SSUS-C have high internal consistency and test-retest reliability. Furthermore, they showed that the SSKS-C and SSUS-C were positively correlated with life satisfaction and classroom adjustment and negatively correlated with depression and stress. Therefore, the SSKS-C and SSUS-C showed sufficient reliability and validity, which is equivalent to that of the full versions.

However, developing short scales requires careful psychometric consideration. Although short scales have practical advantages, there are potential limitations inherent in item reduction. For example, Goetz et al. (2013) and Smith et al. (2000) caution that reducing the number of items may limit a scale's ability to capture the full complexity of a psychological trait by narrowing construct coverage. Ultra-short scales, such as the SSKS-C and SSUS-C, present unique challenges, including potentially reduced measurement stability and limited ability to detect subtle individual differences across diverse populations. These concerns underscore the critical importance of rigorous psychometric validation during the development process. The SSKS-C and SSUS-C were designed to address these limitations through the systematic application of item response theory (Oguni et al., 2025). This approach enabled the selection of the most informative items while maintaining measurement accuracy equivalent to that of the full versions. However, as with all short scales, it is important to understand the appropriate application situations to achieve these scales' optimal performance. The short versions, SSKS-C and SSUS-C, are well-suited for large-scale research studies and educational screenings where time is limited and efficient assessments are necessary. They are also a practical and efficient alternative in studies with repeated measurements or multiple outcome assessments. This allows researchers to obtain valuable information while minimizing participant burden. The full versions, SKS-C and SUS-C, may offer additional detail for detailed individual profiling or intervention studies where detecting subtle changes over time is particularly important. Although the current validation demonstrates sufficient psychometric properties within the studied populations, continued evaluation across diverse cultural contexts, age groups, and educational settings is necessary to establish the generalizability and robustness of these scales. Ongoing validation ensures that the practical advantages of short scales do not compromise measurement quality. Ultimately, this allows researchers and practitioners to select the most appropriate scale for specific situations and needs.

Interventions that target character strengths are effective in improving the wellbeing of children and adolescents (Proctor et al., 2011; Quinlan et al., 2015). For example, the Awesome Us strengths program, developed in New Zealand, encourages children and adolescents aged 9–12 years to discuss recent events in terms of character strengths and to share their own and others' character strengths (Quinlan et al., 2015). The program aims to teach participants that perceptions of character strengths vary across individuals and that using character strengths is part of daily life. The results demonstrated that improvement in positive emotions and class cohesion and a decrease in class friction. Additionally, the Strengths Gym program, which was developed in the United Kingdom, encourages children and adolescents between the ages of 12 and 14 years to learn about character strengths, recognize their own and others' strengths, and apply them (Proctor et al., 2011). The authors reported increases in positive emotions and life satisfaction. These findings imply that nurturing character strengths in children and adolescents can yield various benefits.

However, certain challenges must be overcome to nurture the character strengths of children and adolescents. The current review presents the educational environment in Japan as an example of these challenges. In Japan, the elementary, junior high, and high school curricula are based on courses of study by the Ministry of Education, Culture, Sports, Science, and Technology (2017). The curricula include core subjects, such as the Japanese language, mathematics, and science, as well as moral education, special activities, and career education (Ministry of Education, Culture, Sports, Science, and Technology, 2017). Many school events and club activities are also conducted. Additionally, in the upper grades, class time, study content, and homework increase. Furthermore, the working hours of teachers in Japan are much longer than those of teachers in other countries (Ministry of Education, Culture, Sports, Science, and Technology, 2020). Thus, the schedules of children, adolescents, and teachers in educational settings in Japan are hectic. The subsequent text presents the practical challenges that prevent the implementation of interventions for nurturing character strengths among children and adolescents in Japanese school settings.

The first issues pertain to curriculum positioning. The curriculum in Japan is organized according to course of study; thus, identifying the placement of interventions for character strengths in the curriculum is important (Ministry of Education, Culture, Sports, Science, and Technology, 2017). Currently, character strength interventions are implemented during class time through special activities (Izumi, 2019). However, the consistency between these interventions and educational content lacks a comprehensive discussion. For example, Izumi et al. (2021) propose the development of a cross-curricular approach that follows the learning and teaching processes of multiple subjects and domains instead of a single one. Doing so will enable the continuous implementation of character strength interventions in school settings. This approach is significant because it cultivates self-understanding, which is necessary for vocational education (Izumi et al., 2021). It can also be implemented continuously, because it is based on multiple subjects in the curriculum (Izumi et al., 2021). The second issue refers to the time and period of intervention. Character strength interventions consist of several sessions lasting from 60 min to 90 min conducted over weeks or months (Proctor et al., 2011; Quinlan et al., 2015). Implementing these costly interventions is difficult in countries and regions with curriculum overload. Therefore, identifying elements that produce strong intervention effects and developing short-term interventions that focus on these elements are necessary initiatives. The third issue denotes intervention content. Typically, researchers conduct interventions for character strengths. However, to sustain these interventions in school settings, implementation by teachers who have close contact with children and adolescents is desirable. Therefore, the time and period of the intervention must be shortened and simplified. For example, the Strengths Tree application was developed for children and aimed to cultivate a flower of strengths by identifying one's own and others' character strengths (Abe, 2023). By combining the application with two brief lessons on strengths (45 min and 15 min), interventions for character strengths that can be easily and continuously implemented were developed. Implementing these intervention programs in school settings is easy. Thus, they reduce the burden on teachers by shortening the implementation period and increasing ease of implementation. This aspect is important when formulating sustainable intervention programs in school settings. Therefore, to implement interventions for character strengths in school settings, elucidating their place in the curriculum, shortening the time and period of intervention, and simplifying the content of the intervention are necessary aspects.

Although this review primarily focused on the educational environment in Japan, similar challenges, such as curriculum overload, time constraints, and teacher workload, are reported in other countries and regions (Organization for Economic Co-operation and Development, 2020). For example, character strengths interventions in the United Kingdom (Strengths Gym) and New Zealand (Awesome Us) have been shown to be effective (Proctor et al., 2011; Quinlan et al., 2015). However, as in Japan, developers of these programs have pointed out the need to use short self-report scales to reduce participants' burden and to adopt methods that are convenient for schools (Proctor et al., 2011; Quinlan et al., 2015). Therefore, when implementing these programs in countries or regions with more time and structural constraints, modifications to the intervention period and content may be necessary.

Similar challenges are observed in other parts of Asia. For example, the educational systems in China and South Korea are often characterized by high academic pressure and exam-oriented curriculum, which limits the time available for non-academic programs (Dello-Iacovo, 2009; Kim and Kim, 2021). Nevertheless, some programs have emerged that incorporate character strengths and social-emotional learning into moral education and homeroom activities. In Singapore, for example, the Ministry of Education has emphasized values and character education, incorporating related activities into its national Character and Citizenship Education curriculum (Sim and Tham, 2025). However, even within these structured frameworks, the practical implementation of character strength interventions often competes with academic priorities, and teachers face similar constraints in terms of time and resources. These examples suggest that implementing character strength interventions requires adapting to specific educational environments and institutional contexts, not only in Japan but also in other countries.