Strengthening the Teaching and Research Nexus (TRN) in Higher Education (HE): Systematic Review of Reviews

Abstract

Background: The linkage between teaching and research—also labelled the Teaching Research Nexus (TRN)—is the object of a recurrent debate in higher education. The debate centres on the nature of the interrelation, TRN benefits and challenges, concrete TRN strategies, and its impact on students and academics. Methods: Based on a systematic search of papers published between 2012 and 2022, a systematic review of review studies was conducted, building on articles from the Web of Science and Scopus. Results: From an initial 151 records, 14 fit the review inclusion/exclusion criteria. Goal and review questions: To provide researchers, teachers, and policy decision-makers with an overview of TRN in higher education based on available peer-reviewed review studies, this systematic review was driven by the following guiding questions: What are the conceptual developments in TRN definitions? What are the outcomes of experimental TRN interventions? What are the implementation challenges of TRN in higher education? What TRN implementation strategies have been adopted? Finally, what do the reviews stress as future directions for TRN? Brief conclusion: The review results helped identify patterns in TRN studies, practices, and directions for future TRN research in higher education.

1. Introduction

Worldwide, higher education systems face challenges resulting from their expansion, diversification, massification, and questions concerning their social relevance [1,2,3]. This has had an internal and external impact on the university environment. Externally, universities face accountability questions by constituents and stakeholders; how they deal with the increasing diversification of the student population and the jeopardy in designing and executing their own intellectual agenda [4]. Internally, these impacts have been observed in the way universities reorganize their structure, redefine their mission, and reconsider the relationship between teaching and research [5,6,7]. Teaching and research are two major functions of higher education institutions (HEI). Therefore, the questions concerning their relationship are not surprising, and are part of a recurrent debate in the higher education literature [7].

During the last decade, both non-systematic and systematic review papers have been published focusing on TRN in higher education. The debate has often created controversies, since it involves multiple university stakeholders with diverging interests [8]. On the other hand, the value of the teaching-research nexus remains unclear [9]. Non-systematic reviews do provide relevant summaries about TRN practices in higher education, and are a source of ideas, information, context, and arguments both in favour and against. However, they are not comprehensive or controlled in terms of the selection and inclusion of empirical studies. Systematic reviews, in contrast, help address potential bias and can fulfil the role of a scientific gyroscope with an in-built self-righting mechanism [10]. However, a comprehensive overview of the patterns and results of review studies has not yet been conducted. Thus, the current study offers a review of systematic review studies conducted on TRN in higher education.

2. Trends in TRN Research

Though popular, resilient, and widespread, the relative importance of teaching and research and their relationship have been intensely contested [11]. While in the English higher education tradition, teaching and research were seen as better carried out in separate institutions, in the German tradition, by contrast, one sees the unity of teaching and research as the core university business. In the American tradition, both roles are regarded as co-existing in varying relations alongside community service and industrial consultancy [12,13]. The English higher education tradition is anchored in the Ruth Newman idea of a university; the German tradition is closely connected to the Von Humboldt idea of a university; and the America tradition is associated with the Clark Kerr idea of a university. Following these traditions, and incorporating conceptual debates [12,14], the discussion also expands to the empirical and pedagogical level [15]. Recently, the discussion has influenced policy reforms and the ranking of university systems in the post-pandemic world [16].

At the conceptual level, the debate focuses on the nature and the idea of a university and higher education in general [13]. These discussions were fuelled by [17], who reviewed TRN models based on expected relationships (positive, negative, neutral) and TRN models, within which various moderators and interaction variables are considered.

At the empirical or pedagogical level, both qualitative or quantitative approaches [7,18,19,20] have been adopted to analyse TRN and develop evidence about its benefits, challenges, strategies, and future directions. The quantitative studies typically assess linear correlations between the output of teaching and research activities, respective research productivity, and teaching effectiveness. Most quantitative studies conclude that teaching and research (i.e., the output of both activities) are, at most, marginally correlated [20]. However, there are questions concerning the use of quantitative analysis of the relationship between research and teaching. Alternative approaches build on partial correlations that control the influence of a set of specific variables [19]. Available qualitative research studies emphasize this TRN complexity and adopt interview tools, focus groups, case studies, and reflective approaches to explore the nexus, academic conceptions of “teaching” and “research” at the level of disciplines and departments, and the impact of institutional, disciplinary, and other contextual factors influencing student experiences of research [21]. Qualitative studies usually report a strong belief among university stakeholders that teaching and research are positively related. Specifically, most respondents indicate that this positive relationship predominantly works in one way, with the impact of research on teaching being far more important than the other way around [8].

In addition to the two abovementioned levels, a more recent debate has focused on the societal impact of higher education, with questions about global expansion, diversification, massification, the social relevance of higher education, the vocational dimension of higher education, and the high-specialisation of research in the post-pandemic world. Within this debate, TRN has been introduced as an idea, a theory, a practice, or a catchphrase, as well as a model, a framework, a policy, or a concept [13]. These variations—and their related ambiguities—result from the fact that they are often found in policy-making statements, policy documents for HE, mission statements of universities and other institutions of higher education, etc. (see [5,7]). However, “authors, academics, and policymakers tend to slip between different meanings in an unacknowledged and usually unrecognized way” [22] (p.3). Therefore, the way in which the “nexus” is described in case studies and in the literature reflects the multiple linkages and relationships being referred to [18]. These linkages about the TRN have been primarily perceived as: (a) “functional interdependence” of two academic roles; (b) “conceptual connections” between teaching and research; and finally, as (c) arguments about the roles of graduate and postgraduate students in the context of contemporary “knowledge societies”.

Over time, the reconceptualization of TRN has led to implications for “theory” and “enhancements efforts” in terms of: (i) a deeper appreciation of wider social structural forces in thinking about the nexus; (ii) conceptions of teaching and research—and the linkages between them—as drawing on wider ideological resources which have structural roots; (iii) comprehending ideologically-founded sets of compatibilities and incompatibilities between teaching and research; and (iv) considering differences in the cultures of institutions.

During the last decade, both non-systematic and systematic review papers have been published focusing on TRN in higher education. Review studies are conducted to illustrate the broader picture of a particular topic or focus within a discipline with the purpose of examining the changes and evolution of a discipline to provide scholars with a better understanding of the development of a field and discover any trends [23].

However, the growing number of reviews focusing on TRN in higher education again raises new questions, as different conclusions, challenges, and results are continuously being presented. This seems partly related to the nature of the review itself. Based on a review typology [24] and approaches to synthesizing research [10], three types of reviews can be distinguished: traditional literature reviews, critical reviews, and systematic reviews. Additionally, a review of available TRN review studies is—to our knowledge—currently not available. Therefore, the aim of the present study is to provide researchers, teachers, and policy decision-makers with an overview of TRN in higher education based on available peer-reviewed review studies. Based on the above, we put forward the following guiding research questions:

RQ 1: What are the conceptual approaches and potential changes available in the definitions of the TRN in higher education when looking at TRN reviews?

RQ 2: What are the benefits of an experimental TRN intervention as perceived by academics and students, and as stressed in the review studies?

RQ 3: What are the perceived challenges as to the implementation of the TRN in higher education as stressed in the review studies?

RQ 4: What concrete TRN implementation strategies are discussed in the TRN reviews?

RQ 5: What are the future directions of the TRN in higher education according to TRN reviews?

3. Methodology

3.1. Data Collection

To conduct the systematic review of review studies, we followed the PRISMA guidelines (i.e., preferred reporting items for systematic reviews and meta-analyses) and protocol of the PRISMA Group, 2020 [25]. Review studies published in English between 2012 and 2022 were included in the process, which were available through the Web of Sciences and Scopus.

An overview of the related process is represented in Figure 1.

3.2. Eligibility Criteria

The systematic literature review was started by searching relevant publications. Two queries were set up: a first query via the Web of Science database, and a second query via Scopus. The purpose of the main query was to identify relevant peer-reviewed research on the topic. On 1 August 2022, the following combinations of search field tags and search terms were used in the Web of Science: Teaching AND Research AND Nexus AND Review. The additional query was TITLE-ABS-KEY (“Teaching Research Nexus”) AND “Review”. This was repeated using the Scopus database on 4 August 2022. This second query helped identify recent work on the topic, not (yet) included in the Web of Science database. The following time window was consistently applied: 2012–2022.

The search yielded 151 publications, which were all manually screened to verify whether they focused on the topic of the TRN in higher education and whether they were correctly labelled as review papers. A final set of 14 review papers were used as the basis for the review of the reviews.

3.3. Screening and Selection

Relevant publications were exported to a Microsoft Excel spreadsheet reporting the title, abstract, keywords, authors’ names, journal name, year of publication, language, and document type. This screening was carried out on the basis of inclusion and exclusion criteria, as listed in

Table 1. Inclusion and exclusion criteria.

Inclusion Criteria	Exclusion Criteria
Original research papers focusing on the framework of the TRN	The publication is out of scope of the TRN
Papers published between 2012 and 2022	Papers published outside the time window
Reported setting is University level.	Non-university educational context (elementary, high school, or unspecified)
Limited to English language	Written in a language other than English
Reported as review papers	Individual empirical TRN study (either qualitative and/or quantitative)
A full text is available for retrieval	Unavailable full text

.

An overview of the study of each record is summarized in

Table 2. Type of review, year of publication, and country of origin.

Review Type	Authors
Narrative review	[12,16,26,27,28,29]
Critical review	[13,14,30,31]
Systematic review	[15,32,33,34]
Year of publication
2012–2017	[14,15,26,27,28,29,31]
2018–2022	[12,15,16,30,32,33,34]
Country of origin of review
UK	[12,13,16,19,30,31,32]
Australia	[14,26]
South Africa	[28]
Norway	[34]
Chile	[15]
Spain	[33]
Ireland	[29]

.

3.4. Data Analysis

In view of the findings obtained in response to the five research questions, the selection of publications was coded through a thematic analysis. Thematic analysis provides a flexible approach that results in a rich and detailed, yet complex account of data [35]. The thematic coding focused on five main themes central to the research questions: definition, benefits, challenges, strategies, and future directions. A ‘theme’ is considered as a lens by which to capture a perspective, and contributes to developing a level of patterned response or meaning within the dataset [36]. Although thematic analysis is very often presented as a six-step linear process [35,36], our data analysis approach was instead characterized as an iterative and reflective process, constantly moving backwards and forwards between phases involving the first and the second author. In addition to thematic analysis, information was also collected regarding reported statistical effects. This is discussed separately in the results section. Analysis of quality was guaranteed by repeatedly reading through the data and re-checking the coding, and decisions were then discussed in the research group until agreement was reached between the first author and the second author.

4. Results

4.1. Descriptive Analysis and Review Quality Assessment

4.1.1. Review Types and Year of Publication

The set of fourteen review studies—published between 2012 and 2022—reflects methodological diversity. We identified ten non-systematic TRN review studies (traditional narrative reviews (N = 6) or critical reviews (N = 4)), and four systematic review papers. Grouping review types over time, narrative reviews were more dominant in the period between 2012 to 2017 [26,27,28,29]. From 2018 till 2022, systematic reviews became the prevailing review type [15,32,33,34].

Review studies originated from seven different countries and most reviews were mainly published by authors from the U.K. [12,13,16,19,30,32]. This could reveal stronger support, in a modern context, for the Humboldtian ideal of unifying teaching and research among English academics [12].

4.1.2. Teaching and Research Nexus: Review Aims and Questions

Over time, and by observing the aims or questions outlined in the review papers, we observed that only five studies (N = 5) explicitly reported or contained a review aim and review question; seven reported a general aim, and two did not provide review aims.

Table 3. Review aims and Questions.

Author	Review Aim	Review Questions
[26]	To advance understanding of the concept by exploring the literature that underpins it.	Not reported
[14]	To encourage new discourse on how higher education institutions can integrate research in discipline, scholarship of teaching (for and from), and teaching practice, by focusing on action needed to engage students in authentic learning to develop a broader range of knowledge and skills within, and across, disciplines.	Not reported
[27]	Addresses the knowledge gap by advocating a novel approach to research-informed teaching, which adopts a risk-management philosophy.	Not reported
[28]	Engage in a critical discussion of the relationship between teaching and research.	Not reported
[31]	A critical review of the literature around the constructed relationship often termed the ‘research-teaching nexus’.	How, and how well, questions raised within the specific research have been addressed
[29]	To explore the conceptual and instrumental arguments for linking research and teaching.	Not reported
[13]	To provide a comprehensive account of how the idea of the TRM has developed and been applied.	Not reported
[30]	To explore the dominant agenda of research-led teaching excellence, centred on the idea of the productivity of research, and outline an alternative notion of teaching-led research, developed out of the work of Boyer and Walter Benjamin, within which teaching might continue, in spite of excellence.	Not reported
[15]	To provide relevant evidence for university teachers, curriculum designers, and academic managers to decide what type of learning experiences they may organize for students.	Which type of experiences are most beneficial for science students to develop as scientists?
[32]	Systematic review of the literature to consider the implications of established and emergent themes and contested ideas from/for different perspectives.	What, if any, is the impact of Exploratory Practice (EP) in terms of: (a) global reach; (b) global uptake; (c) implementation in different contexts (e.g., primary, secondary, tertiary education)? What are the theoretical themes and insights emerging from the literature? What are the (epistemological, methodological, pedagogical) affordances and/or constraints of enacting EP? How do the conceptual and theoretical developments in EP relate to Applied Linguistics, Language Education, and beyond?
[33]	To establish how Inquiry-Based Learning (IBL) is used and what effects it has on university students from social sciences and health sciences.	What are the origin, duration, and methodological characteristics of the studies? What IBL mode do they use? What type of objectives are set and what are the effects on the students? What are the limitations of the studies analysed?
[34]	Not reported	Which barriers to students’ active learning are identified in research on university campus development and technology use in higher education?
[12]	Not reported	How has the understanding of research shifted over time?
[16]	Outlines the argument that the pandemic has further exposed [the dysfunctions between the two core missions of a university—research and teaching].	[What is the] impact on sectoral and institutional discrepancies between research and teaching? How student and staff experience the link between research and teaching that changed during the pandemic? What sort of university would serve its citizens and wider community better in a post-pandemic era?

provides the details of the review aims and questions.

As illustrated, the review studies provided a range of aims and research questions appropriate to the topic of TRN in higher education. While some critically discussed the relationship between teaching and research [28,29,34], others centred on providing empirical evidence or arguments to ground the nexus [13,15,29,33]. Some review studies advocated novel approaches [27], looked into particular effects [33], or centred on dysfunctions [16] of TRN in higher education. Overall, the review of the review studies helped to develop a very diverse picture of TRN as a field of study that is difficult to allocate to just one perspective or problem field. This seemed dependent on stakeholder perspectives and wider changes in the context of higher education (e.g., the COVID-19 pandemic).

4.1.3. Review Methods and Exclusion and Inclusion Criteria

Five reviews contained an explicit statement that the review methodology was defined prior to conducting the review [13,15,32,33,34], and nine failed to do so [12,14,16,26,27,28,29,30,31].

Only five reviews contained an explicit statement about inclusion/exclusion criteria [13,15,32,33,34], and, in nine reviews, this item was not applicable due to the review type, i.e., traditional narrative review or critical review [12,14,16,26,27,28,29,30,31].

4.1.4. Review Methodology Limitations and Declaration Statements

Thirteen reviews did not address review methodology limitations [12,13,14,15,16,26,27,28,29,30,31,32,34], except one that explicitly mentioned methodology limitations [33].

In eight reviews, the authors did not report potential sources of conflict of interest, including any funding they received for conducting the review [14,26,27,28,30,31,32,33].

4.1.5. TRN: Conceptualization, Benefits, Strategies, Challenges, and Future Directions

All reviews provided conceptualizations regarding TRN, benefits from different stakeholder perspectives, addressed strategies for TRN implementation, challenges, and future TRN directions. In general, the reviews reflected a detailed picture by which to tackle this research question; see summary in

Table 4. Quality assessment of the 14 reviews discussed.

Author		Quality Assessment Questions
	Q1	Q2	Q3	Q4	Q5	Q6	Q7	Q8	Q9
[26]	No	Yes	NA	Yes	Yes	Yes	No	Yes	No
[14]	No	Yes	NA	Yes	Yes	Yes	No	Yes	No
[27]	No	Yes	NA	Yes	Yes	Yes	No	Yes	No
[28]	No	Yes	NA	Yes	Yes	Yes	No	Ye	No
[31]	No	Yes	NA	Yes	Yes	Yes	No	Yes	No
[29]	No	Yes	NA	Yes	Yes	Yes	No	Yes	Yes
[13]	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes
[30]	No	Yes	NA	Yes	Yes	Yes	No	Yes	No
[15]	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes
[32]	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	No
[33]	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	No
[34]	Yes	Yes	Yes	Yes	Yes	Yes	No	Yes	Yes
[12]	No	Yes	NA	Yes	Yes	Yes	No	Yes	Yes
[16]	No	Yes	NA	Yes	Yes	Yes	No	Yes	Yes

Notes: Question 1: Did the report of the review contain an explicit description of the review methods applied? Question 2: Did the report of the review contain TRN conceptualization? Question 3: Did the report of the review contain an explicit statement that the review methods applied inclusion/exclusion criteria? Question 4: Did the review authors provide TRN benefits for different stakeholders? Question 5: Did the review authors provide strategies for implementing TRN? Question 6: Did the review authors provide challenges for implementing TRN? Question 7: Did the review authors provide a limitation of their review? Question 8: Did the review authors point out future directions on this topic? Question 9: Did the review authors provide a disclosure statement for conducting the review? NA: Not applicable.

. We discuss this richness in relation to the following research questions.

4.2. What Are the Conceptual Approaches and Potential Changes in Concepts in the Reviews of TRN in Higher Education?

The Teaching Research Nexus was clearly conceptualized in all review studies. Three levels were distinguished in the conceptualisations:

(a)

TRN as part of a long tradition to debate the nature or the idea of a university and/or higher education;

(b)

TRN as a description of higher education teaching practices or pedagogy;

(c)

TRN as a departing point to critically reflect on the mission of higher education.

These concepts are used to highlight the differences of at least three different traditions of debating the nature or the idea of university, namely, the English, the German, and the American higher education traditions. As previously mentioned, the English higher education tradition is anchored in the John Henry Newman idea of a university, the German tradition is closely connected to the Von Humboldt idea of a university, and the American tradition is associated with the Clark Kerr idea of a university. These traditions reflect the pre-Humboldtian, the Humboldtian, and the post-Humboldtian approaches [13,14,16,28,29]. In the pre-Humboldtian approach, teaching and research remain institutionally separated, even though links are created between extra-university research bodies and universities. In the Humboldtian approach, the two are funded from the same source and academics adopt both roles, and the organisation is stable. In the post-Humboldtian approach, there is an organisational movement towards differentiation in both roles, and in related funding structures and processes [16].

As a description of higher education teaching practices or pedagogy, the concept is used to distinguish modes of enhancing the quality of learning at the university level, during courses, and the classroom experience [13,15,27,30,32,33,34].

Further reflecting on the mission of higher education, review studies stress the pressures inflicted on universities due to social, economic, and political changes [12,13,30].

Three review studies conceptualized TRN while reflecting on its historical evolution, and stressed how the face of TRN has changed due to changes in the higher education context or in terms of global developments [12,30,31]. The concept was used to chart the historical transformation of higher education from the legacy of the British ‘colonial college’ to the dominance of the German research university [30], or to articulate the gradual swing of the pendulum from one extreme to the other [12]. The nature of how understandings of TRN have shifted over time form the focus of these review papers by drawing on historical literature to explore these changes.

4.3. What Are the Benefits of an Experimental TRN Intervention as Perceived by Academics and Students?

Data analysis helped to summarise the reported benefits of experimental TRN interventions. While some benefits were related to student processes and variables, others were related to academics. All review papers presented student-related benefits. Some review papers (N = 8) provided benefits related to both students and academics [13,14,26,27,28,29,30,31]. Student-related benefits were linked to: (i) the development of high-level competencies (such as problem formulation, data analysis, writing, collaboration, and critical thinking); (ii) student cognitions; (iii) research competences; and (iv) personal and discipline-oriented skills. Academic-related benefits were linked to: (i) the teaching process; (ii) pedagogical skills; and (iv) opportunities to refresh knowledge.

Table 5. Benefits of an experimental TRN intervention.

	TRN Benefits
Authors	Student-Related Benefits	Academic-Related Benefits
[30]	Development independence of thought, entrepreneurial and transferable skills, and the ability to handle uncertainty and new problems central to rapidly evolving workplaces of the knowledge-economy.	Restructuring both the pedagogical and the integrative aspects of the research university experience to make research-based learning the standard.
[29]	Enhanced knowledge and expertise for all; intrinsic knowledge-creation and problem-solving value; enhance faculty expertise, communication skills, and methodological awareness, enriching pedagogical quality; empowering and enthusing students; strengthening bonds between educators and students, generating new research ideas, and providing insights into what researchers do.	Linking research and teaching is perceived to lead to enhanced knowledge and expertise for all; enhancing academic credibility; strengthening bonds between educators and students, generating new research ideas, and providing insights into what researchers do.
[28]	It contributes to improved teaching effectiveness, improves student learning outcomes, and may ultimately change academic cultures and communities.	It contributes to improved teaching effectiveness, and may change academic cultures and communities.
[14]	Students develop the broad range of knowledge and skills required for them to make effective contributions within, and across, disciplines.	An alternative to the current divisive approach to viewing research and teaching as non-integrated, competing components of higher education.
[26]	Positive perceptions of the value of staff research for student learning. Students gained tangible benefits from staff research, mainly through students perceiving that their courses were current and intellectually stimulating.	Teaching and research roles as mutually supportive.
[16]	Supports students “to think critically, to analyse problems, and to make decisions in the face of complex knowledge”.	Not reported
[27]	Empowering and enthusing students; strengthening bonds between educators and students; generating new research ideas and providing insights into what researchers do.	Enhancing academic credibility. Strengthening bonds between educators and students; generating new research ideas and providing insights into what researchers do.
[31]	Development of graduate attributes and graduate outcomes; intellectual and attitudinal development of learners; sustains an actionable link between graduate employability and the challenges of (…) super-complex society.	Curriculum construction.
[15]	Positive effects on students.	Not reported
[12]	The student learns the ability to question received wisdom as the distinguishing feature of higher education.	Not reported
[32]	Student (and teacher) motivation levels increased.	Not reported
[33]	Promotes active learning with positive effects on students’ achievements and their attitudes towards research; stimulates their problem-solving capacity, critical thinking, and reflection on learning; fosters university students’ research competence and training, improving the quality of what they learn and the process of peer collaboration; promotes better understanding of subjects among students; increases their academic writing skills.	Not reported
[34]	To promote student active learning.	Not reported
[13]	Student attitudes revealed to be generally positive, with students appreciating being taught by academics who are actively engaged in researching their subject.	Students appreciating being taught by academics who are actively engaged in researching their subject.

provides a detailed overview of the reported benefits of experimental TRN interventions in higher education.

4.4. What Concrete Implementation TRN Strategies Are Discussed by TRN Reviews?

Review studies on the teaching-research nexus offered a large variety of TRN strategies. These placed considerable emphasis on student participation and/or considered how academics use their own pedagogic research to inform teaching.

A range of concepts were used to describe TRN implementation strategies: as a framework [14,29], a model [12,13,14,16,26,28,29,33,34], a form or approach [14,15], or as a list of recommendations [13,26,27,28] situated within contexts ranging from a discipline, a department, and an institution in a small-scale or large-scale project involving undergraduate and/or postgraduate students.

Table 6. Strategies of TRN in higher education.

Strategies of TRN in Higher Education
Framework	Authors
Research Skill Development (RSD) framework	[29]
The Scholarship-Teaching-Action-Research (STAR) framework	[14]
Scholarly and Research Activity (SandRA)
scholarship-teaching-action-research framework	[13]
Models
Research-tutored Research-based Research-led Research-oriented	[12,13,14,16,26,28,29,33,34]
Teaching-led research Teaching-based research Teaching-informed research Teaching-led research	[30]
Forms
Undergraduate Research and Research-Based Courses	[15]
Communities of Practice	[14]
Situated learning
Descriptive approaches or recommendations
Drawing on personal research in designing and teaching courses. Placing the latest research in the field within its historical context in classroom teaching. Designing learning activities around contemporary research issues. Teaching research methods, techniques, and skills explicitly within subjects. Building small-scale research activities into undergraduate assignments. Involving students in departmental research projects. Encouraging students to feel part of the research culture of departments. Infusing teaching with the values of researchers. Conducting and drawing on research into student learning to make evidence-based decisions about teaching. Research findings are disseminated in lectures and tutorials. Having students carry out research or be involved in discussions about the ideas. Having students (especially postgraduates) engage in research that is relevant to their professional and academic interests. Students and teachers engaging in collaborative research. Faculty level, inquiry/problem based. Sufficient time for students to undertake projects and assignments that are research or industry related. Build up from inquiry/problem-based approaches and teaching of research-related skills in earlier courses. Developing institutional awareness and institutional mission. Developing pedagogy and curricula to support the nexus. Developing research policies and strategies to support the nexus. Developing staff and university structures to support the nexus. Improving understanding of research-informed teaching within the discipline. Better guidance and support from the institution and higher education community on implementation Reflection on policies, culture, practices, and values to identify gaps in delivery processes. Strong leadership to maintain equal quality in teaching and research, as well as increasing confidence within teaching. Support for individual academics, including reward systems that recognize and encourage a ‘step-change toward more research-informed teaching’. Improving understanding of research-informed teaching within the discipline. Scholarship and consultancy.	[13,26,27,28]

presents the details of review strategies of the TRN in higher education.

4.5. What Are the Perceived Challenges as to the Implementation of the Teaching and Research Nexus (TRN) in Higher Education?

Considering the variation of implementation strategies, all TRN review studies uncovered many challenges in higher education. These challenges were related to students, academics, institutions, and policies. The same issues were sometimes described as risks [27] or barriers [32,34]. The most comprehensive review reporting a detailed overview of challenges was in [27]. This review adopted a risk management approach to identify (a) intrinsic, (b) extrinsic, and (c) learning risks.

Most review papers (N = 12) focused on intrinsic risks. This included risks that lay within the actual teaching practices, such as those emanating from curriculum design, lesson planning, delivery in the classroom, and quality of the teaching. Some review papers (N = 5) paid attention to extrinsic risks. These were related to impacts on the teacher from outside the teaching process (institutional policies, government directives, and economic climate). Particular challenges involved the changing nature of academic work and how teachers were influenced by the tension between involvement in teaching and/or research. The latter was often linked to management and funding issues. A smaller number of reviews (N = 5) tackled learning risks or risks identified from the student perspective; for example, when research engagement impacts students’ overall learning experience, or when individual students struggle to cope with additional demands of the research-based learning method.

Table 7. Challenges of TRN in higher education.

Challenges	Authors
Intrinsic Challenges:
A facilitative, responsive andragogy, a broad repertoire of academic knowledge and theories, as well as familiarity with a range of research approaches. Academics’ ability to integrate research and teaching. Balance practical advantages of research-based courses with the more intense undergraduate research experiences. Conflicting time pressures upon [academics] to increase research outputs at the same time as improving the quality of teaching. Curriculum and instruction vs professional experience. Disciplinary or departmental culture. Formal evaluation. Increasingly diverse and demanding student body. Individual academics’ perceptions of the teaching research nexus and the development their own academic identity. Modelling research-teaching linkages. Research-based courses and undergraduate research programs meet minimum standards for qualifying as research. Teaching tradition in higher education. The massification of contemporary higher education The research intensiveness of the institution Volume of students	[13,14,15,16,26,28,29,30,31,32,33,34]
Extrinsic challenges:
Change in the nature of academic work. Clear demarcation between research- and teaching-focused institutions. Existing vulnerabilities across the system. Limitations derived from the university structures. Managements approaches. National research funding policies. Rankings and institutional priorities and practices regarding Teaching and Research. Renewal of a long-standing debate over the relative value of discipline-based research. Teaching as practice and scholarship of teaching. Sectoral and institutional inequalities of research funding. Stratified university system. University’s societal role.	[14,15,16,26,29,33]
Learning challenges:
Feelings of alienation and abandonment. Inequalities of access and progression in higher education in general and research in particular Mass participation means not everyone can do research. Students may resist their introduction to new ways of teaching. Students remain recipients of research or become unpaid research assistants.	[14,16,26,33]

provides a detailed overview of the reported TRN challenges in higher education.

4.6. What Are the Future Directions of TRN in Higher Education?

Review studies provided interesting future directions for TRN. These did not reflect a return to the so-called ‘golden age of academe’ [12], but mainly showed how TRN is influenced by very actual and urgent global challenges, such as environmental destruction, climate change, conflict, and socio-economic inequities [16].

Only one review directed attention to the methodology being used [15]. Some reviews (N = 3) addressed future directions at the conceptual level or frameworks being used [12,26,27]. Others (N = 4) dealt with future practices or pedagogy to implement TRN [13,16,32,33]. Most reviews (N = 5) stressed future directions at the institutional and policy level [13,16,27,31,34].

Table 8. Future directions of TRN in higher education.

Future directions of TRN in Higher Education	Authors
Conceptual level or Framework
Future research should address formal evaluation of these approaches and direct comparisons with traditional approaches. Further empirical research to test the broader veracity of the framework. Re-establish the spirit of research and value the way in which research awareness, rather than research productivity per se, can enrich university-level teaching with a critical, research-informed perspective.	[12,14,26]
Methodological approach
Data collection at different times during the development of experiences (e.g., prepost) to establish whether they influenced students or not, with a benchmark (pretest). Use of a comparison group (e.g., research-based courses versus traditional courses). Inclusion of longitudinal studies for determining whether the effects of student participation in the various types of research experiences are maintained over time after they have finished. Use of statistical analysis, in the case of quantitative studies, that make some comparison (e.g., prepost) to determine whether achievement levels perceived by students are different from each other.	[15]
Practice or Pedagogy
Cover other fields of knowledge and educational stages. Renew the ways of thinking and working together within and across disciplines and fields. Further surfacing of hitherto hidden links and connections across disciplines, with acknowledgement of the potency of practitioners.	[13,16,32,33]
Institutional Policy and Management
Build a system that is more equitable and inclusive to both students and staff, more flexible in its organization, strongly rooted in its wider community, less obsessed with competition, and much more collaborative in nature. An integrated infrastructure for research and teaching in higher education institutions will support research-based teaching as this requires systematic, continuous development of teaching practices and will open a scholarly approach to teaching. [Detailed research] in the relation between policy—at international, national, institutional, or departmental level—and practice at the micro-level, where academics and their students, [engage in both teaching and research]. Providing a sector-wide perspective of the risks involved in [TRN] and how to effectively manage them. [Re-address] the questions of baseline quality, policy, outcomes, and value [of TRN in Higher Education].	[13,16,27,31,34]

summarizes these in more detail.

4.7. Reported Statistical Effects in the Review Studies

As described in the discussion of review results above (see Section 4.3; What are the benefits of an experimental TRN intervention as perceived by academics and students?), all review papers provided evidence about student-related benefits, and some review papers (N = 8) put forward benefits related to both students and academics. The availability of statistical data from these review papers is necessary to explicitly consider results from comparable prior research, thus allowing the aggregation of this statistical body of knowledge at a higher level of analysis, interpretation, and conclusion [37]. This is critical for a topic where debate often creates controversies and involves multiple university stakeholders with divergent interests [8]. It also seems crucial in the case of the TRN, since the actual evidence base remains unclear [9]. This is partly due to the fact that teaching and research are often loosely coupled, while being deeply nested within very different organizational structures [38]. Therefore, descriptive discussions are hard to generalize across contexts. In contrast, relying on statistical data could make a difference [38]. It is widely recognized that the proper use of statistics is a key element of research integrity [39] and scholars have provided guidelines for experimental [40] and quasi-experimental designs [39], as well as appropriate statistical procedures to back empirical evidence [37,39,40,41,42].

Surprisingly, only two review papers reported statistical effects of TRN interventions on students. Indeed, one [33] used descriptive statistics to report the percentage of studies reporting the effect of TRN on: (i) students’ improved understanding of subjects and of their relevance to society; (ii) increased collaboration between students when working together to achieve a common goal; (iii) an increase in joint responsibility in carrying out tasks; and (iv) improved interpersonal skills and skills in performing work roles. Furthermore, the second [15] reported p-values related to positive effects on: (i) students’ understanding of the natures of research work; (ii) professional practice; (iii) attitude and behaviour for practicing science; (iv) interest in science; (v) career options; and (vi) students’ confidence level while being engaged in research-based courses and undergraduate research programs. Basic descriptive statistics alone are insufficient to carry out a higher-level of statistical analysis. Therefore, a higher level statistical meta-analysis of the review studies could not be carried out.

5. Discussion and Conclusions

This systematic review of reviews provides an overview of the TRN in higher education based on literature searches conducted in the August 2022. It reveals that the available review studies allow us to answer key questions concerning the conceptual bases and the evolution in definitions of TRN. The benefits, as perceived by academics and students, types of TRN challenges, and a range of instructional strategies can be used guide its implementation in higher education. Lastly, a structured overview of future directions of TRN could be further developed. However, the review also pointed out a lack of statistical rigour in the reporting of studies. This implied that no meta-analysis could be carried out.

The present review highlighted a methodologically diverse picture in terms of conducting reviews, considering the gradual increase in the adoption of a systematic approach in recent years. The latter meets the growing demand to pursue statistical rigour and move away from non-systematic reviews [43]. The growing adoption of systematic reviews follows growing trends in review research in other domains; e.g., review studies regarding hospitality and tourism [23], social protection [44], as well as in gerontology and health services [45].

As demonstrated in this paper, available review studies largely differed in their methodological approach because of a focus on multiple university stakeholders with diverging interests [8], and often resulted in a very wide overview which was unclear on the value of the TRN [9].

The current study helped by comparing and contrasting review studies, and by developing a structured state-of-the-art approach. This study revealed that a conceptual analysis of TRN highlighted variations in traditions of debating the nature or the idea of universities. On the other hand, it can be used as a description of higher education teaching practices or pedagogy to distinguish modes of improving the quality of learning at the university level, during courses, and the classroom experience. Moreover, the TRN is helpful as a starting point to reflect on the mission of higher education in the context of current social, economic, and political changes. Similarly, there has been agreement among scholars regarding the benefits of (experimental) TRN intervention. These are related to student learning outcomes and the development of a wide range of competences that go beyond graduation. Outcomes for academics are related to their teaching and research practices, but also reflect a meso-level impact on curricula and academic culture. When it comes to the question regarding TRN strategies, the review findings placed considerable emphasis on student participation and/or a consideration of how academics use their own pedagogic research to inform teaching. However, all of the TRN higher education review studies also uncovered intrinsic and extrinsic challenges related to students, academics, institutions, and educational policies. Combining research and teaching seems to stretch resources (time, expertise, funding), demands (priorities), and policies (role of university teaching and learning). Future directions for TRN in higher education included incorporating conceptual questions, methodological recommendations, TRN practices, and TRN-related policy developments.

6. Limitations and Future Research

This systematic review has some limitations. First, some available review studies could not be included in our study based on the inclusion/exclusion criteria. The studies could nevertheless have added to the richness of the data already described above. Precision is required when analysing peer-reviewed research, and analysis of non-English, non-peer reviewed, or excluded studies or reports (such as those found via Google scholar) could help in confirm the present picture of the status of the TRN in higher education or add elements or dimensions not yet identified. Nevertheless, the current analysis could serve as a benchmark for future review studies.

The second limitation is related to the methodological diversity of review studies included in the present systematic review. As reported, between 2012 and 2022, six were classified as traditional narrative reviews, four as critical reviews, and another four as systematic review papers. This might raise the question concerning the level of comprehensiveness or balance in the present analysis. Themes identified through systematic analysis were not ‘quantified’ and could not be studied as to their importance in the TRN debate. In addition, the diversity in TRN research involving very different samples also makes analysis and synthesis difficult. A next-level analysis could be adopted to reanalyse the studies incorporated in the review studies.

Despite these limitations, the findings of the present review helps develop an initial benchmark regarding the status of reviews on the TRN in higher education. It can inform researchers and teachers about the broader nature of TRN, and might inspire other researchers, teachers, and policy-makers to consider the broader picture. This can be achieved against a background of the changing nature of higher education considering the changing demands of society. In the post-COVID period, a stronger emphasis on the societal relevance of higher education can inspire universities to reflect on their own policies and practices, and define how teaching and research are mutually beneficial in supporting the graduation of alumni that fit into the framework of a future-oriented (global) society.