At present, the international understanding of micro-credentials has not reached a consensus ( Brown, Mhichil, Beirne, & Mac Lochlainn, 2021 ). Many researchers and professional organizations have defined the concept. For example, The State University of New York defined micro-credentials as “verify, validate and attest that specific skills and/or competencies have been achieved”. The National Education Association of US defines a micro-credential is a short, competency-based recognition that allows an educator to demonstrate mastery in a particular area ( Duklas, 2020 ). The definition of micro-credentials varies significantly depending on who is using the term and in what context ( Brown, Mhichil, Beirne, & Mac Lochlainn, 2021 ; Brown & Mhichil, 2021 ). In order to solve the problem of definition confusion and lack of common language around micro-credentials, the European Commission’s Higher Education Consultation Group developed a definition:

A micro-credential is a proof of the learning outcomes that a learner has acquired following a short learning experience. These learning outcomes have been assessed against transparent standards ( European Commission, 2020 ).

Following the European Commission definition, a micro-credential ( Duklas, 2020 ; UNESCO, 2021 ; Oliver, 2019 ):

· Is a record of focused learning achievement verifying what the learner knows, understands or can do;

· Includes assessment based on clearly defined standards and is awarded by a trusted provider.

· In addition, a micro-credential ( Oliver, 2019 ):

· Has stand-alone value and may also contribute to or complement other micro-credentials or macro-credentials, including through recognition of prior learning; and

· Meets the standards required by relevant quality assurance.

The micro-credentials correspond to the traditional degrees as macro-credentials. They represent the mastery of a limited set of skills or competencies, rather than the broader, interrelated set of skills represented by traditional degrees in the current credentialing system ( Ehler, 2018 ). From the perspectives of credit, micro-credentials also have been labelled in different ways around different countries or regions. In the United States, they are described as “more than a single course but less than a full degree” ( Kato, Galán-Muros, & Weko, 2020 ). In the European Higher Education Area, the initiated MicroHE project regards micro-credentials as “sub-unit of a credential or credentials that confer a minimum of 5 European Credit Transfer and Accumulation System (ECTS) (credits) and could be part of a portfolio” ( MicroHE Consortium, 2019 ). In New Zealand, micro-credentials are assigned a range of credits from 5 to 40 credits, while in England, the higher education credit framework assigns credit to each qualification based on the expected effort (notionally 10 hours per credit point) ( Msweli, Twinomurinzi, & Ismail, 2022 ).

Furthermore, some definitions specify the characteristics of micro-credentials ( Msweli, Twinomurinzi, & Ismail, 2022 ; Pollard & Vincent, 2022 ; DeMonte, 2017 ):

· Competency-based. Micro-credentials focus on explicit evidence connected to the learner’s specific competencies, not on the amount of time they spend learning. As for micro-credentials focus on developing a discrete set of competencies, their narrow range of learning enables students to obtain micro-credentials faster than most traditional credentials ( Pichette, Brumwell, Rizk, & Han, 2021 ).

· Personalized. Learners select micro-credentials based on their interests and career goals. They identify specific activities that will support them in developing each competency.

· Flexible/On demand/Self-directed. Learners can earn micro-credentials by undertaking and completing specific activities at their own pace. They also can opt to explore new competencies or receive recognition for existing ones any time of the day.

· Shareable. Learners can share their micro-credentials across many platforms, through email, and on blogs and résumés. As a result, micro-credentials are portable currency that learners can take with them wherever they go.

Micro-credential is an umbrella term that encompasses various forms of credential, including “nano-degrees”, “micro-masters credentials”, “certificates”, “badges”, “licences’’ and “endorsements” ( Duklas, 2020 ). Because there are so many types of micro-credentials, people often cannot distinguish the boundaries and relationships between them. Holon’s recent report defined six areas on the micro-credential spectrum: 1) short courses and badges, 2) bootcamps, 3) professional certificates and licenses, 4) non-university-issued non-degree certificates, 5) university-issued non-degree certificates, and 6) degree programs or accredited programs ( Holon, 2021 ). The types of micro-credentials are distinguished by calculating the “hours of learner effort”. Brown et al. classify credentials into four categories by “bundled and unbundled” and “credit-bearing and non-credit-bearing”. Following this typology, micro-credentials are unbundled, credit-bearing, stackable credentials. While digital badges or certificates that are non-status awards are differentiated with micro-credentials.

In addition, according to the relationship with the national qualification framework, micro-credentials can be divided into credit and non-credit-bearing micro-credentials. Credit micro-credentials mean they are recognized by the national qualification framework and the credit they represent is consistent with the traditional credit. Non-credit-bearing micro-credentials exist outside the formal qualifications frameworks of traditional universities and colleges. This mean they are not recognized by the national qualification framework and may not be stackable or combinable towards higher qualifications ( McGreal & Olcott, 2022 ).

At present, the popular micro-credentials are mainly digital badges and open badges

1) Digital badges. Digital badges as a representation of achievement, interest, or affiliation, with visual, online available features, and containing metadata with links to help interpret context, meaning, process, and results of activities ( Gibson, Ostashewski, Flintoff, Grant, & Knight, 2015 ). Grant proposed that digital badges are digital images obtained by accomplishing some pre-specified objectives and annotated with metadata ( Grant, 2016 ).

Digital badges are presented as “visual symbols of certificates” and web technologies with “the potential to identify and connect cross-context learning”, designed to reward learners for achievement in specific activities. Unlike regular analog badges, digital badges can contain detailed metadata about the learner, the badge issuer, and the evidence that the badge was submitted. A digital badge is a web-based symbol of learning outcome that contains specific statements and evidence of learning and achievement, consisting of images and associated metadata.

2) Open Badges. The Open Badge is a digital badge based on an open technical specification created and promoted by the Mozilla Foundation in 2010. It allows learners to authenticate their skills, interests, and achievements through trusted institutions, and in order to ensure future access and inspection, metadata such as the awarding organization, awarding criteria, awarding time, corresponding achievement evidence and possible expiration date of the badge were hard-coded and attached to the badge image file ( Jovanovic & Devedzic, 2015 ). In addition, more detailed evidence of learning, such as a study diary or practical work produced during the study process, will be attached to the badge. The main feature of open badges is the collection of meta-badges obtained from different sources in a single digital-space badge, that is, the use of technology to combine selected badges into custom profiles. This way of “merging all information into one” greatly alleviates the boundary problem of different situations and institutions in credit transfer.

Information about a micro-credential is stored as metadata for future access and review. The metadata makes the “identity” of the micro-credential clear. It answers when the micro-credential was issued, who issued it, who earned it, and what its specific reward was. The metadata of micro-credentials including required data (unique ID, earner’s information, issuing issuer information, badge name, description, criteria, and date of issue) and optional data (evidence, narrative explaining evidence, expiration date, corresponding educational standard, label describing achievement, and whether the badge was valid) ( Clements, West, & Hunsaker, 2020 ). According to the metadata, the authenticity of the badge can be verified by referring back to the issuing site.

In the field of education, micro-credentials is a new assessment mode and an innovative educational concept. Whether teachers and students accept and support this new mode will become a real issue in the development process of micro-credentials concept.

In terms of student reception, most participants had a positive impression of micro-credentials as credible and innovative ( Dyjur & Lindstrom, 2017 ). An in-depth survey of 104 digital badge recipients at the Irish Institute of Technology revealed that while 90% had never come across a digital badge, they found it easy to accept and 75% said they would use it on LinkedIn and their CVs (Curriculum Vitae) ( O’Brien, 2019 ). A comparative study on the attitude of MOOC learners in developed countries (Sweden) and developing countries (Kenya) towards micro-credentials show that learners in both countries regard MOOCs based on micro-credentials as a supplement to traditional learning, but learners in developing countries pay more attention to micro-credentials than learners in developed countries ( Jobe, 2014 ). Students generally agree that micro-credentials can help them better understand course content, focus on specific learning objectives, and explore curriculum competencies in greater depth ( Fajiculay, Parikh, Wright, & Sheehan, 2017 ), but some worry that employers may not recognize the value of micro-credentials ( O’Brien, 2019 ).

From the perspective of teachers’ attitude, teachers will face a series of challenges when using micro-credentials, and they may also become a digital badge gainer. Therefore, teachers’ attitude towards micro-credentials is also crucial. A study of 99 K-12 teachers who received digital badges in a teacher training program found that teachers were positive about accepting micro-credentials, and many shared their badges through digital media ( Jones, Hope, & Adams, 2018 ). Teachers have a positive view of the use of digital badges as an integral part of their own learning curriculum ( Basal & Kaynak, 2019 ).

Micro-credentials enable teachers’ professional development to change to a more personalized direction. They support competency-based, personalized professional development mode, and provide teachers with a more diversified certification system for learning outcomes. The researchers found that “one-shot” workshops are the most prevalent form of teacher professional development, but they did not change teacher practices or improve student learning ( Dan & Barnett, 2017 ). The most effective professional development is contextualized to the specific needs of teachers, where they have opportunities to take ownership of their professional learning ( Dan & Barnett, 2017 ).

It is in this context that micro-credentials have been applied in the field of teacher education, which targets teacher competence promotion, pays attention to teacher needs and interests, focuses on practical outcomes, and allows teachers to show what they can do rather than just what they know. Compared with the traditional teacher professional development system, the advantages of the learning system based on micro-credentials are that it is based on competence, respects personalized characteristics, meets needs and can be shared.

Micro-credentials are being used to certify learning outcomes during classroom teaching in English, chemistry, medicine and STEM, providing a formal certification mode and framework for multiple content components in a discipline. In the case of a chemistry lab, students submit a video of themselves completing an experiment as a learning outcome to a micro-credential system, which then grades and gives feedback based on a series of criteria. Students who successfully demonstrate the experiment receive a digital badge. In view of the digital nature of micro-credentials, the corresponding learning evidence is also in the form of digital. In classroom teaching, the learning outcomes of Micro-credentials system are generally based on videos, and the characteristics of videos enable students to self-evaluate and evaluate each other before submitting learning outcomes ( Seery, Agustian, Doidge, Kucharski, O’Connor, & Price, 2017 ).

In addition, some scholars pay more attention to the impact of micro-credentials on curriculum design. For example, Song (2018) found that micro-credentials can also be used as an effective tool in curriculum design. Firstly, the digital badges under the micro-credentials system are associated with verifiable data and evidence, and represent a skill that students are expected to develop during the course, and teachers can test whether students have acquired that skill with a question or a series of questions. Among them, digital badges should be as detailed as possible to cover more and more comprehensive knowledge points. Song created 113 digital badges for a single course. Secondly, teachers can design courses based on the knowledge points of digital badges. From the perspective of course management, micro-credentials can also help to better evaluate the teaching effect of teachers and allow teachers to design teaching freely according to their own style.

A digital badge system is a nascent technology that intends to recognize, validate, and in some cases even accreditize non-formal learning ( Jobe, 2013 ). As an emerging technology, micro-credentials can achieve certification of learning outcomes in all forms, including informal learning. The process of acquiring comprehensive knowledge, skills and attitudes in different learning environments and different ways at different stages of life can be visualized, and can be digitally displayed and publicized online. That is, a widely recognized organization accorrding to different purposes and methods to evaluate learning outcomes or abilities, and award the learners corresponding qualification or equivalent credits. For informal learning such as online learning and blended learning, micro-credentials can play a key role as a bridge between different learning frameworks. Open Learn of the Open University of UK has thousands of hours of learning materials, and attracts more than 14 million visitors each year from around the World ( The Open University of UK, 2022 ). In 2013, the platform tried to carry out a micro-credentials pilot project and developed a series of Badged Open Courses (BOCs). Students receive a digital badge when they complete the course and pass a test ( Law, 2015 ). Comparing the demographics of BOCs learners to OpenLearn’s overall demographics, they found that more and more learners are keen to achieve this informal learning outcome.

The micro-credentials, especially digital badges have come to be recognized by the education community as an innovative instructional and credentialing strategy. The existing academic literature, project reports, and a large number of case studies suggest that micro-credentials can support teaching in four ways:

1) As a motivational mechanism. Micro-credentials can be used as an effective motivational mechanism to stimulate learners’ motivation by giving a series of scientifically planned rewards. They can significantly improve student goal-setting and motivation in learning, especially for students with low self-regulated learning level, the use of micro-credentials has better incentive effect ( Cheng, Richardson, & Newby, 2020 ). A micro-credential assigns a learning goal that each student can achieve at his or her own pace.

For example, Bovermann et al. developed a gamified learning project based on the Moodle learning management system using digital badges and progress bar elements. In this project, the awarding of a digital badge is technically linked to the completion of a specific online activity, task or online group work, and once a student has completed relevant and predefined activities as required, the digital badge is automatically added to their profile. Using micro-credentials as a reward element in game design to develop learning content can incentivize learning ( Bovermann, Weidlich, & Bastiaens, 2018 ).

2) As a means of assessment and credentialing learning. Micro-credentials provide identification and assessment of learning outcomes during teaching. They can be used as a new teaching evaluation method to solve people’s dissatisfaction with the current dominant standardized test, especially for the evaluation of specific professional skills and abilities. Micro-credentials’ value is largely dependent on the credibility of the recognizing and credentialing process. Artevelde University College (AUC) in Belgium offers a variety of community service learning projects, but these informal learning experiences and achievements are not recognized, which greatly affects the participation enthusiasm of students. To this end, the AUC has developed a micro-credential program called Gentleman Student. Once a student has completed a challenge or learning opportunity according to the relevant criteria, the ability they have gained is recognized and an open badge is awarded.

3) As a means of charting learning routes. Through displaying evidence of learning in an effective, transparent, learner-centered manner, micro-credentials draw a learning roadmap for each learner. A series of standards and requirements for obtaining micro-credentials are the “signposts” in the learning process. Learners can complete their personalized learning according to the “signposts” provided by teachers. For example, The Center for Cooperative Education (CCE) and The Center for Teaching Quality (CTQ) launched a Learning program (PAL Program) based on micro-credentials, which are designed at three levels ( Deklotz, 2016 ). In the learning process, micro-credentials are regarded as learning “signposts”. After the learner completes the learning tasks step by step and obtains the assessment and recognition of the learning results, all micro-credentials are achieved, which means the completion of the learning plan.

4) As a means of supporting self-reflection and planning. A micro-credential is a record of focused learning achievement verifying what the learner knows, understands or can do. This record can be used as feedback in teaching by enabling learners to constantly review what they have learned and consider the next step of learning, to develop their self-reflection and planning ability.

At present, researchers mainly discuss the impact of micro-credentials on learners’ learning intrinsic motivation, learning participation (engagement), learning behavior and learning performance.

In terms of intrinsic motivation, specific badges can highlight achievement, and competitive badges can enhance learning motivation ( Facey-Shaw, Specht, & Bartley-Bryan, 2018 ). There is evidence that micro-credentials provided additional formative and summative feedback beyond what is traditionally available in higher education classes and that additional assessments provided by badges had a positive impact on student motivation to learn ( Boesdorfer & Daugherty, 2020 ; Abramovich, 2016 ; van de Laar, West, Cosma, Katwal, & Mancigotti, 2022 ). In terms of learning participation (engagement), learners’ achievements are displayed and their learning paths are captured by obtaining micro-credentials through the certification of their knowledge, skills and abilities on the online platform, thus motivating them to continue to participate in learning ( Mah, 2016 ). In terms of learning behavior, digital badges that can represent academic performance can be used to influence students’ learning behavior and have a certain incentive significance ( Hakulinen, Auvinen, & Korhonen, 2015 ). Micro-credentials can motivate specific behaviors of students with as little change to the course structure as possible ( Uanhoro, Young, & Lin, 2016 ). In terms of learning performance, micro-credentials have a significant positive impact on learners’ self-efficacy and learning performance ( Yang, Quadir, & Chen, 2016 ). Learners based on micro-credentials learning not only have higher perceived confidence in their technology integration skills, but also achieve higher levels of coursework and overall course performance ( Newby & Cheng, 2020 ).

In addition, based on the micro-credentials, it can ensure that instructors in the same course have the same coverage of basic concepts/topics, at the same time teachers have flexibility in the course designing. Not only learners but also instructors can carry out personalized teaching according to the learning map drawn by the micro-credentials.

With the mission of promoting lifelong learning for the masses, the Open University of China has been providing adult education with both academic and non-academic degrees all over the country with the support of modern information technology. It uses its own online platform to carry out distance education and open educational resources to learners through the Internet. At present, there are some problems in distance teaching in the Open University of China, such as emphasis on knowledge mastery and neglect of ability cultivation, teachers completely dominate the teaching process, difficulty in ensuring the learning quality and good learning status of students, and low social recognition of non-academic learning outcomes. Micro-credentials can help The Open University of China solve the above problems to some extent.