Project-based Learning in Vocational Education: A Bibliometric Approach

Vocational education is a form of education that prepares students for trades, industry, and other practical occupations. It is designed to provide students with the knowledge and skills they need to be successful in a specific industry or business [1]. The implementation of vocational training is one of the elements of the government's success in improving the quality of human resources, especially in developing skilled workers. Vocational education emphasizes not only the mastery of knowledge but also the mastery of skills [2]. The history of vocational education can be traced back to the 19th century, when the Industrial Revolution increased the number of specialized trades and industries. Many people then began acquiring vocational training through apprenticeships, where they worked with experienced artisans and learned on the job [3]. Vocational education began to be structured and institutionalized with the creation of vocational schools and programs at high schools and universities in the early 20th century. These programs were created to provide students with the necessary skills and information to excel in various jobs and industries [4].

In vocational education, a learning system refers to the techniques and resources used to teach and assess the skills and information required for a specific job or career. Hands-on training, experiential learning, classroom instruction, and instructional resources such as textbooks, films, and simulations can be included. A vocational education learning system aims to provide students with the skills and information they need to be successful in their chosen career, be it a skill such as carpentry or electrical work or an industry such as healthcare or business [5]. While this term refers to the learning model, it also refers to the methodology or method used to teach and assess the skills and information required for a specific job or career.

Whether the learning model is most appropriate for vocational education has long been debated. It is crucial for vocational programs to select the learning model that best suits the goals and needs of their students, as well as the specific careers or professions for which they are being trained. On the other hand, the project-based learning (PjBL) approach is considered the most developed. Students in this model work on real-life projects that challenge them to use the information and skills they have learned throughout the curriculum [6]. This paradigm is seen as a 21st-century vocational education method capable of applying an active learning model. Project-based learning plays a significant role in supporting the reform of professional computer education and has an excellent practical impact on developing innovative skills in students' vital teaching tools [5].

The term PjBL (project-based learning) is used in this study to emphasize the focus on vocational education. For example, the PjBL learning model is applied in vocational high schools in Indonesia, resulting in more active and creative students. This research uses the term "project-based blended learning," which combines the project-based learning model with blended learning [7]. In another study, the term PjBL was also used to find out whether students in higher education vocational cosmetology programs were interested in using Google Classroom with a project-based learning approach in their courses[8]. Likewise, Jang Seung-hwan, from Duksung Women`s University, Seoul, Korea, used the term PjBL in his research related to the implementation of PjBL models in vocational education and workforce development in various countries [9].

PjBL is more commonly associated with vocational education, where the focus is on developing technical skills and practical knowledge that can be applied in a specific trade or industry. Additionally, the use of PjBL in this study helps to distinguish it from other forms of project-based learning, such as engineering design projects, communitybased projects, and service-learning projects, which may have different goals and outcomes. By using the term PjBL, this study emphasizes the specific application of project-based learning in vocational education, highlighting the unique challenges and opportunities that arise in this context. Both PjBL and PBL involve students working on projects, PjBL emphasizes the development of technical skills and practical knowledge in a specific trade or industry, while PBL focuses on developing critical thinking and problem-solving skills through the process of working on a complex problem or challenge. On this basis, the term PjBL is used because it is more in line with the philosophy of vocational education.

The rationale for this study is to analyze the use of project-based learning (PjBL) in vocational education comprehensively. The increasing implementation of the PjBL model in vocational education is an intriguing research topic as it aligns with the rapid development of information technology[10]. It is in line with the rapid development of information technology, which enables PjBL in vocational education to help students develop problem-solving, critical thinking, and collaboration skills. While providing them with the opportunity to practice the technical skills learned and apply them in a practical context of media media-based learning.

Based on relevant articles, this research work intends to analyze the use of the PjBL model in vocational education comprehensively. In this study, a bibliometric approach is used to provide insight into the structure of the subject, social networks, research trends, and themes. This study aims to review the literature and identify the most important nations, authors, contexts, and sources for project-based learning models in vocational education. The conceptual framework for this review is based on the principles of project-based learning and vocational education. The framework will be used to categorize and analyze the publications, authors, and themes identified in the bibliometric analysis. The framework will enable the analysis of the literature based on these key concepts, identify research gaps, and provide a comprehensive overview of the use of the PjBL model in vocational education. Additionally, this study intends to identify research streams and topics by searching the Scopus database for publications from 2010 to 2022.

2.    Method

Bibliometrics is a statistical method for collecting and evaluating written knowledge from scientists in books, journals, and other publications [11]. Bibliometric analysis can be broadly classified into descriptive analysis, which focuses on identifying underlying patterns in knowledge generation [12]. It also applies scientific mapping and network analysis methods to demonstrate knowledge-based relationship patterns [13]. In particular, bibliometric studies show recent advances in various areas, as they can provide important information, such as the most popular keywords and authors and the most frequently addressed topics [14].

Retrieve from Scopus database, November 2022

Stage 1

Searching formula: TITLE (“project-based learning”) = 2,702 documents

Stage 2

Filtering: (TITLE (“project-based learning”) AND TITLE-ABS-KEY (vocational) OR TITLE-ABS-KEY (tvet)) AND (LIMIT-TO (LANGUAGE, “English”)) AND (LIMIT-TO (SRCTYPE, “p”) OR LIMIT-TO (SRCTYPE, “j”)) = 60 documents

Bibliometric Analysis

Analysis 1

General Result (Main information, Annual scientific production, citation)

Analysis 2

Impact Sources (Relevant sources, Source clustering)

Analysis 3

Impactful Authors and Country (Relevant authors, Authors production, Top affiliation and country)

Analysis 4

Keyword analysis, Themes, and Research Trends (Frequent words,

Co-occurrence network, Thematic map)

Fig. 1. Bibliometric procedure in Project-Based Learning in vocational

This study used Scopus, a recognized database index that provides complete research results and information. The search was conducted on the Scopus database on November 27, 2022, using the search terms (TITLE ("project-based learning") AND TITLE-ABS-KEY (vocational) OR TITLE-ABS-KEY (tvet)) AND (LIMIT-TO (LANGUAGE, "English")) AND (LIMIT-TO (SRCTYPE, "p") OR LIMIT-TO (SRCTYPE, "j")). The search string consists of compound terms concatenated with the AND and OR operators. The first search field contains project-based learning terms to search in the title. The term vocational or TVET appears in the second search field's title, abstract, and keywords. As a result, all publications on project-based learning at vocational schools were discovered, as shown in Figure 1. We limited our study to journal articles or proceedings in English to keep it relevant.

Consequently, a linked paper entitled “Creative project-based learning approach to promote the creativity of professional high school students” was discovered in December 2022 in the International Journal of Evaluation and Research in Education [15]. According to Usmeldi and Risda Amini, creative project-based learning methods can encourage students' inventiveness concerning products and work attitudes. Other research by Seung-Hwan Jang, in his article titled "Case analysis of overseas countries in project-based learning for vocational education and human resources development", published in April 2022 in the International Journal of Emerging Technology and Advanced Engineering, describes project-based learning as an educational method that can effectively develop future skills, such as 4C or 21 ^st -century skills needed in vocational training.

This study used Bibliometrix, created by Aria and Cuccurullo and coded in the R programming language, to conduct quantitative research in bibliometrics [16]. It contains essential statistical and scientific mapping analysis methods, as indicated in Figure 1 above. The VOSviewer software was used to map the collection of articles [17]. VOS works to display literary data and can visualize written material in picture maps [18].

3.    Result, Analysis, and Discussion 3.1    General Result

In the first part of this chapter, we deal with the annual scientific output of publications on project-based learning in vocational education and training. From 2010 to 2022, we discovered 60 publications in Scopus-indexed journals and proceedings. Sixty percent are conference papers, and forty percent are journal articles. The modest annual growth rate of 17.6% suggests that this topic is of no interest to researchers. Figure 2 shows the annual number of publications and total citations per year.

Fig. 2. Articles published by year, 2010-2022 (n=60) and mean total citation per year

The article by Utku Kose from Afyon Kocatepe University, Distance Education Vocational School, Turkey, was first published in 2010 and presented at the 2nd World Conference on Educational Sciences, WCES-2010. He developed a web-based method that allows students to learn web design and programming by creating a website using sophisticated tools [19]. The following year, Hsu Yu-Ping presented Technology-Integrated Project-Based Learning in the Classroom at the International Conference on Technology for Education (IASTED) in December 2011 in Dallas, Texas, United States [20]. In particular, this research focuses on developing technology-integrated project-based learning as a resource for technical and professional teachers in higher education.

According to other work by Al-Sarawi et al. (2011), project-based learning is an innovative teaching style that has proven itself in vocational schools [21]. They ensure the explicit development of these skills as part of their course delivery using the educator-developed Research Skills Development (RSD) framework. This research was presented in Bursa, Turkey, during the 7th International Conference on Electrical Engineering and Electronics (ELECO 2011). In 2011, only these two articles were published.

Before 2019, research on the PjBL model could have been more interesting. No relevant research was discovered in 2013 or 2014 either. Due to the development of the PjBL model in traditional education in these years, vocational education research was not yet intensive. In 2019, the number of publications more than tripled compared to the previous year, peaking in 2020 and then declining in 2021 and 2022. It was attributed to the epidemic encouraging researchers to publish more frequently.

For example, a six-citation article that received much attention in 2019 looks at the impact of problem-solving skills-based approaches to learning on learning outcomes. It was developed by Retno N.H.D. et al. (2019) at the 3rd International Conference on Science and Science Education, IConSSE 2019, Salatiga, Indonesia. They claim that project-based learning approaches could be used as an alternative for teachers to conduct their learning, foster an active learning environment, and improve students' skills. Other research by Edy et al., highlighted the impact of project-based learning on online learning in VET at the 4th International Conference on VET, ICOVET 2020, in 2019 [22]. Analysis of learning during the COVID-19 pandemic revealed variations and improvements in student learning outcomes. With seven citations this year, this piece has garnered much attention.

Table 1. Articles by subject area (Scopus)

The Scopus database classified the subject in Table 1. The top 3 disciplines are social sciences (20.9%), engineering (19.1%), and physics and astronomy (19.1%). The publication of Utku Kose from Afyon Kocatepe University is an essential publication in the field of science, with 23 citations [19]. As mentioned, his study was the first to appear in the 2010 Scopus database. It was published in Procedia: Social and Behavioral Sciences. He has developed a web-based system for students to learn web design and programming.

Meanwhile, Dogara et al. (2020) cited PjBL ten times in their study to establish a conceptual PjBL framework for soft skills integration among college students. They pointed out that the government should provide appropriate facilities for PjBL activities to improve soft skill integration. The factors identified by PjBL should be incorporated into soft skills teaching and learning in technical institutes to successfully integrate soft skills into students lives. Publications by Retno et al. (2019) have attracted considerable attention in physics and astronomy, having been cited six times. This paper, published in the Journal of Physics: Conference Series, reviews the impact of physics problemsolving skills through project-based learning on college students.

There may still be gaps in research on project-based learning methods in vocational education after 13 years. Research on PjBL in vocational education can be costly and time-consuming for several reasons, such as those listed above. Funding sources are required to conduct a meaningful study of the effectiveness of this vocational education paradigm. Another reason is that PjBL is very tough on vocational education from a pragmatic point of view. For example, regulating some factors that might affect student learning in a project-based context is possible. In the future, however, more relevant research will be carried out regarding the possible use of PjBL in professional settings, especially concerning technological advances.

• 3.2    Impact Sources

Document analysis analyzes the intellectual structure of a knowledge topic by determining the amount and authority of the referenced literature. Table 2 shows the ten most cited articles according to Scopus citation data.

Table 2. Top ten most cite documents in PjBL vocational education

In particular, Habok et al. (2016), Utku Kose (2010), and Dogara et al. (2020) each received a total of 72 citations in Scopus and were rated as the three most cited articles. The study by Habok et al. (2016) examines teachers' perspectives on the methods, roles, and effectiveness of project-based learning [23]. The research is based on accurate primary and vocational secondary school data. Most educators preferred project-based methods, and oral assessment was one of the main methods to actively involve students in the assessment process. Utku Kose (2010) describes a webbased system designed and built to support project-based learning activities in vocational schools, offering a web design and programming course [24]. According to the results, the students received a well-designed web-based system and a strategy used for project-based learning activities. Students' overall academic performance has the potential to improve significantly when they use the method.

Dogara et al. (2020) establish a conceptual PjBL framework for integrating soft skills in technical college students when they are in third place [25]. According to the results of the study, the PjBL preparation (planning), application, obligation, and evaluation approach has a positive influence on the development of soft skills among students at universities of applied sciences. They found that encouraging project-based learning has a significant but negative association with soft skill integration among students in higher education.

Fig. 3. Top five most source in PjBL vocational education research

The year 2010 marked the beginning of research on the use of PjBL in vocational education. The development of this study, on the other hand, only started in 2016, when UNESCO published its Strategy for Vocational Education and Training (2016-2021) [33]. Education, training, and skill development in various professional fields, production services, and lifestyles are included in vocational education. For this reason, vocational education has evolved into Technical and Vocational Education and Training (TVET), which includes various work-related programs.

The vast majority of sources relevant to this research are in the form of conference proceedings. As mentioned, conference papers account for about sixty percent of all work done on PjBL related to vocational education. According to the data, since 2018, the Journal of Physics Conference Series has been the most productive venue, where 16 documents have been produced as conference papers. The article that has had the most significant impact is that of Retno N.H.D. and his colleagues, and presented at the 3rd International Conference on Science and Science Education held in 2019 in Salatiga, Central Java, Indonesia [34]. They spoke about the impact that being able to solve physics problems with PjBL can have on the overall learning outcomes of students at vocational high schools in Surakarta, Indonesia. As a result, there is an interaction effect between learning techniques and problem-solving ability regarding cognitive learning outcomes. They suggested that project-based learning approaches could be used as an option for trainers to conduct their learning in an active learning environment. This research has been cited six times in Scopus and published in the Journal of Physics: Conference Series, Volume 1307.

PjBL in Indonesian vocational high schools formed part of the topics that Sudjimat et al. (2018) investigated for their research on the Mechanical Engineering Study Program in Malang. The findings indicate that vocational teachers have applied PjBL in terms of planning, the actual execution of learning, and the assessment of that learning. Because the teachers have not incorporated the industry in the creation of the projects, and because the projects themselves are rather straightforward, the end results of the projects cannot be used or sold. At the 1st International Conference on Vocational Education and Technology, which took place in Bali, Indonesia, in 2018, this study was presented and published in the Journal of Physics: Conference Series Open Access Volume 1165.

The second-place source for this study was also an article from a conference that appeared in AIP Conference Proceedings. On the other hand, only five publications were identified here, in contrast to the Journal of Physics: Conference Series, which published sixteen articles. The publication by Rahmawati et al. (2021), presented at the 2nd Science and Mathematics International Conference: Transforming Research and Education of Science and Mathematics in the Digital Age, SMIC 2020, describes the STEM approach to developing critical thinking skills at vocational high schools in the province of Banten in Indonesia through the use of project-based learning [35]. The results indicate that implementing projects in pre-existing educational settings positively impacts student engagement, motivation, teamwork, and creativity.

A total of three articles were published in the International Journal of Emerging Technologies in Learning and the International Journal of Innovation, Creativity, and Change, both of which are in the top 5. Although they do not contain conference papers, these two journals only appeared in 2019-2020. Outside of that year, there were no articles that were related to this study. Publications regarding developing project-based learning tools for local network device installation, Maulana et al. (2019) wrote an article published in Volume 14 of the International Journal of Emerging Technologies in Learning [36]. The conclusion that can be drawn from this research is that the value is 85.75%. It is very beneficial to learn to install local area network equipment using this model and use it as a reference model for other topics. This article has been cited six times in Scopus, making it the publication that contributed the most.

Jalinus et al. (2020), in the International Journal of Innovation, Creativity, and Change, Volume 11, compared project-based learning models to direct instruction of welding skills and collaborative skills among vocational students [28]. This study shows that due to the different competency ratios of hard skills and soft skills that students possess in a project-based learning model, implementing different learning models is very well suited to 21st-century learning that prioritizes student learning outcomes over soft skills. Scopus referenced this article six times.

• 3.3    Impactful Authors and Country

Project-based learning is a type of education that focuses on hands-on, experiential learning[37,38]. Students in this form of learning are given a problem or challenge that they need to address to work together to find a solution[39]. John Dewey, recognized as the father of experiential learning[40,41], and Milton Chen[42], known for his work on the importance of students taking an active role in their learning, are two authors who have made significant contributions to project-based learning.

Table 3. Top five most productive authors in PjBL vocational education research