Knowledge sharing in organization: A systematic review

Abstract The main objective of this paper is to bring together scattered literature on knowledge sharing, and analyse them to provide a better understanding of the concept and to suggest emerging directions for future research. The review went through three stages: setting the review protocol, administering the review, and reporting the review. The paper systematically reviewed 110 articles under three research streams: (1) knowledge sharing enablers (2) knowledge sharing processes, and (3) knowledge sharing outcomes. The paper found that little is known about the kind of knowledge that better contributes to develop the competencies required for specific market, there is over-concentration on knowledge sharing enablers than barriers, knowledge sharing process is not linked to the overall firm objective and strategy, and financial outcomes of knowledge sharing has been studied more than nonfinancial outcomes. Based on these findings, organisations have been advised to design knowledge sharing processes in line with their overall business objective, strategy, and resources at their disposal to maximise the benefits of knowledge sharing.


Introduction
Knowledge is the crux of, and a crucial element for organizational survival (Islam et al., 2021;Asrar-Ul-Hag et al., 2016). In the recent past, knowledge in organizations has been considered as a critical organizational resource (Nickerson & Zenger, 2004;Nonaka & Takeuchi, 1995;R. M. Grant, 1996) and the basis for creating economic value and competitive advantage (Bock et al., 2005;Drucker, 1993;Eisenhardt & Santos, 2002). As a result, knowledge management has been with us since time immemorial (Wiig, 1997), and has become very important in the life of every organization (Asrar-Ul-Hag et al., 2016). Organizations therefore concentrate on the value of their knowledge and make it unique to make their products significantly different from competitors (Rafique et al., 2018). Because, the effectiveness and success of any organization heavily depends on the quality and quantity of knowledge at its disposal.
Knowledge management activities include knowledge acquisition, encoding, storage, transfer, application and sharing (Deng & Lu, 2022), and one of the most important purposes of knowledge management is to systematically influence knowledge sharing and application to create value (Kozhakhmet & Nazri, 2017). Therefore, knowledge sharing is a key part of the knowledge The aim of this paper is to bring together scattered literature on knowledge sharing and analyse them to provide a better understanding of the factors that impact on knowledge sharing and suggest emerging directions for future research. This review is very essential and different from many other reviews because it is the only review that looks at articles in the light of prime research streams, contextual positions, and influential journals at the same time. This review contributes to a coordinated framework for previous research on knowledge sharing and pinpoints emerging theoretical and methodological topics and arguments. Additionally, it will provide an evidencebased body of knowledge about knowledge sharing, which will inform the research community about the current state of knowledge sharing to provide comprehensive guidelines for practitioners and managers to formulate appropriate strategies for managing knowledge. Finally, the review will also propose an outline of the key areas where future research should be directed.
The rest of the paper is organized as follows. The second section deals with the taxonomy of knowledge sharing. Section 3 discusses the methodology adopted for the review. The fourth section covers the analysis of the research streams to provide the results. Section 5 outlines the future research agenda, and the last section (section 6) is the conclusion and implications.

Methodology
This paper employed systematic literature review approach, which has been widely utilized in qualitative research (Chauhan et al., 2022). This research approach was utilized because it minimises biases (Kravariti & Johnston, 2020) and ensures replicability (Kravariti et al., 2022). In terms of the actual methodology for the review, the paper followed the Protocol, Search, Appraisal, Synthesis, Analysis, and Reporting (PSALSAR) framework (Mengist et al., 2020). The authors developed this method by adding Protocol and Reporting to the Search, Appraisal, Synthesis, and Analysis (SALSA) framework. The PSALSAR framework was utilized because unlike the other frameworks and methods, it is an explicit, transferable, and reproducible procedure to conduct systematic review. It also enables researchers to appraise both quantitative and qualitative content analysis of the literature review (Mengist et al., 2020). Ideally, this method translates into six steps: Protocol (Setting the scope and determining the coverage and the area the review should cover. This helps to reduce the bias by conducting exhaustive literature searches); Search (Defining the search. This phase comprises of searching strategy and delivery. The essence of this is to help define required search string and identify the necessary databases to collect the relevant information.); Appraisal (This deals with screening of the selected literature to identify relevant papers for the review. It has two basic steps: selecting articles using inclusion and exclusion criteria, as well as quality assessment (Mengist et al., 2020); Synthesis (This step comprised of both extraction and classification of relevant data from selected papers to derive knowledge and conclusions); Analysis (The analysis phase bordered on the assessment of synthesized data and the extraction of meaningful information and concluding the selected articles); and Reporting (The reporting phase of the review comprised of the narration as well as the presentation of the methods followed and results obtained from the selected literature).
However, the review covered all the elements of the PSALSAR though, it did not rigidly follow the six steps in the framework. Consequently, the review utilized the ground rules introduced by Kitchenham (2004) and Bahoo et al. (2019) which covers all the elements of the framework with reduced steps and different descriptions. Thus, defining the review protocol, conducting the review, and reporting the review; cumulating into the following elements: (a) inclusions and exclusion criteria, (b) search strategy, (c) data source, and (d) sample selection analysis and reporting (Ahmad & Karim, 2019;Bahoo et al., 2019;Johnston et al., 2016)

Inclusion and exclusion criteria
The selection criteria define what to be included and what to be excluded in this review. The inclusion and exclusion criteria aim at identifying research that are relevant to the research question (Kitchenham, 2004). Deciding the inclusion and exclusion criteria based on journals is critical, and all quality SLRs utilize these criteria (Khan et al., 2021). Thus, this review was confined to scholarly peer-reviewed journals (Chauhan et al., 2022) and characterized by a wide array of empirical context, theoretical perspective, and methods (Meier, 2011). Again, this review deals with knowledge sharing at the individual level therefore, the unit of analysis is the impact of individuallevel knowledge sharing (Ahmad & Karim, 2019). As a result of the multidisciplinary nature of knowledge sharing, the review is not limited to any discipline but all disciplines that deal with the subject. Additionally, the review generally excludes books and book chapters (Kravariti & Johnston, 2020). This is because they do not include original research (Ahmad & Karim, 2019).

Search strategy
Fifteen key words and search terms were used to cover the complete literature on the subject including; knowledge sharing enablers, knowledge sharing processes, knowledge sharing outcomes, barriers to knowledge sharing, impact of knowledge sharing, benefits of knowledge sharing, role of knowledge sharing, effects of knowledge sharing, influence of knowledge sharing, knowledge sharing consequences, knowledge sharing and innovation, knowledge sharing and performance, knowledge sharing and intellectual capital, knowledge sharing and organizational learning, and knowledge sharing implications to search for published papers studying knowledge sharing.

Data source
The key words were used to conduct a search of scholarly literature from the various electronic databases, such as Scopus, EBSCO and ABI/Inform in order not to miss out on articles (Kravariti et al., 2022;Rajwani & Liedong, 2015). However, this allows using complex search strings and filters, which makes it easy to apply complex selection criteria (Bahoo et al., 2019), regarded as appropriate for systematic literature review (S. N. Wang & Noe, 2010). To make our review more inclusive, other major digital libraries, such as ScienceDirect, Wiley, Springer, Sage, Google Scholar, SpringerLink, and Web of Science, were searched for publications on the subject (Chauhan et al., 2022)

Sample selection, analysis, and reporting
Having decided the search strategy and the data source, articles were now identified from all journals on the subject matter. This was done in such a way to avoid selection bias by not only considering top-ranked journals at the initial stage (Terjesen et al., 2016), The initial search yielded a result of 2284 articles on the topic. Now, the articles were screened based on the key words and this gave 1652 articles. To ensure quality, all articles from non-ranked journals were removed, leaving 720 articles. Further pruning was done by removing all articles that are not directly related or relevant to the topic and the objective and the scope , resulting into 425 articles. Per the inclusion exclusion criteria, further scrutiny was done to select only empirical articles. This gave 315 articles for consideration. The number was pruned substantially by removing repeated papers through reading the title and abstract of each article. I then read the full text and further reduced the articles. Finally, after thorough reading and scrutinizing of the articles, the final sample was composed of 110 for analysis. Again, the analysis and synthesis were done by categorizing the articles in respect of author(s) and year of publication, name of journal, research design and methods (Högberg et al., 2018) and the context, with special emphasis on themes. The figure summarises the methodology stylized in the review. Figure 1 below summarises the research methodology utilized in the paper.

Taxonomy of knowledge sharing in organization
Looking at the many definitions given to knowledge sharing, researchers and practitioners have not agreed on a common meaning of the concept thereby, leaving a gap not only in the meaning but also the kind of knowledge that must be shared.

Databases
Step 1: Running search string on databases.=2284 Step 3: Papers from low-ranked journals not considered.=720 Step 5: Only empirical research papers included.=315 Step 7: Read full paper and critically evaluate work.

Definitions of knowledge sharing
Knowledge sharing is regarded as a social interaction in which employees exchange their experiences, skills, and knowledge across the firm (Y. Lee et al., 2021). Knowledge sharing is "a human behaviour, which apprehends activities such as exchanging explicit and/or implicit experiences, embedding ideas and skills that facilitate knowledge for innovation at the workplace" (Kumar & Che Rose, 2012). Knowledge sharing is employee-to-employee learning procedure to assist one another to enhance their potential, solve problems and boost work performance (Nguyen et al., 2021). Knowledge sharing deals with the process of readily making available the relevant knowledge to coworkers in the organisation (S. -W. Lin & Lo, 2015;S. B. Grant, 2016;Z. Wang et al., 2014;Zhang & Jiang, 2015). It is a crucial mechanism through which organisational members commit to knowledge acquisition, innovation, and eventually enhancing competitiveness (Marouf & Khalil, 2015). De Ridder and van den Hooff (2004) posit that knowledge sharing is a process where individuals commonly exchange their implicit and explicit knowledge to create new knowledge. Knowledge sharing is defined as the exchange of task-related information, advice, and expertise to help others and to collaborate with others to carry out daily tasks, solve problems and develop new ideas (Ahmad, 2017). Additionally, Ortiz et al. (2017) state that knowledge sharing occurs when individuals actively share their professional knowledge or experience with others to help them learn new ideas or thoughts. Knowledge sharing is a sustained process of transferring experiences and organisational knowledge to business processes through communication channels among individuals, groups, and organisations (McAdam et al., 2012;O. O. Oyemomi, 2017;Sedighi et al., 2016).
Synthesizing the literature, this review, adopted the definition provided by Nguyen et al. (2021) which states that "knowledge sharing is employee-to-employee learning procedure to assist one another to enhance their potential, solve problems and boost work performance". This review therefore posits that knowledge sharing has three main characteristics: First, knowledge sharing involves a process or procedure for sharing. Implying that knowledge sharing is not an event and relies on communication medium (Sedighi et al., 2016). Second, the individuals share their expertise/experiences with others. This means that knowledge sharing deals with the willingness to donate accumulated knowledge and experience with the willingness to receive (H. F. Lin, 2007). Third, knowledge sharing is geared towards finding solution to organizational problems or generating new ideas. Thus, knowledge sharing leads to innovation and sustained performance (Islam et al., 2021a;2021c)

Types of knowledge
Different types of knowledge essential to value creation within organizations have been identified and documented in the literature. Spender and Grant (1996) identifies four types of knowledge: conscious knowledge, automatic knowledge, objectified knowledge, and collective knowledge. According to Spender, conscious knowledge is individual's expertise that is codified and readily made available to others; automatic knowledge is implicit and remains with the individual; objectified knowledge is knowledge that has been codified and captured at the social level; and collective knowledge is normally implicit and embedded in social norms. Polanyi (1966) categorizes knowledge into tacit and explicit. Tacit knowledge is the kind of unwritten or unspoken knowledge held by individuals based on their experiences, insights, and intuition. This knowledge is difficult to transmit in formal language because is often resides with the individual, whereas explicit knowledge is codified and transferrable in formal language. De Jong and Ferguson-Hessler (1996) identified four types of knowledge namely: situational knowledge (knowledge about situations as they appear in a particular domain); conceptual knowledge (static knowledge about facts, concepts, and principles applicable within a particular domain); procedural knowledge (has to do with actions and manipulations that are valid within a domain); and strategic knowledge (knowledge that enables problem-solvers to organise problem solving process and identify which process to go through to solve a particular problem).
Additionally, knowledge has been classified as information-based; experienced-based; and personal knowledge (Løwendahl et al., 2001). According to the authors, the information-based knowledge is unbiased, and linked to the diary undertakings or functions of the individual; experienced-based knowledge is implicit and biased. It is based on the individual's perspective and understanding; and personal knowledge relates to the individual's capability and genius, predilection, and imaginative capabilities.
Knowledge as a factor of production and knowledge used by intellectuals (Drucker, 2008). The author suggested that knowledge as a factor of production is action-based and used by knowledge workers in their practice whilst knowledge used by intellectuals is theoretical and used in books and scientific journals. Christensen (2007) identified four types of knowledge including professional knowledge, coordinating knowledge, object-based knowledge, and know-who. Professional knowledge is the kind of knowledge that allows the operation support to perform their functions. Coordinating knowledge is explicit on rules, standards, and routines on how specific tasks are performed. In the author's view, certain objects such as a machine is used to perform a specific job in the production line of the organization, and the knowledge related to this is object-based knowledge. Know-who is the knowledge about the source of the relevant knowledge required for solving organizational problem at a particular time.
A critical analysis of the types of knowledge identified in literature are many yet, none of them is linked to a particular industry or context. Thus, little is known about which kinds of knowledge better contribute to develop the competencies required to enter specific market (Magni et al., 2022). Figure 2 below shows the number of articles publised yearly included in the review period

Influential aspects of the literature on knowledge sharing in organization
The analysis comprises of the journals, number of articles, citations, methods used in the studies, theoretical underpinnings, the study settings, and the prime streams (Alon et al., 2018;Paul & Benito, 2018). Table 1 talks about the research questions and their rationale. To show the methodology and theories researchers used to study and report the findings of knowledge sharing. This will enable us to find out whether these settings are enough for studying the topic or not.

RQ4:
How does the literature synthesize knowledge sharing?
To ascertain how the various studies on knowledge sharing have been integrated. This will enable us to get a coherent view and understanding of the topic RQ5: What are the most influential views in the literature regarding key journals, articles, citations and years and their publication To determine the leading and the most influential journal in the field, in terms of citations and number of articles published. This will also help in determining whether research on knowledge sharing is progressing or retrogressing and find out why? And what can be done.  Table 3 shows the number of the selected articles published per year within the review period from 2000 to 2022. It is worth noting that the breakdown of global sources indicates the sharp rise of activity in this topic since 2005. Table 3 reveals that the number of articles increased from 2005 to 2009 but there was a drop in 2010 and 2011. However, from 2012 the number of articles published per year has been fluctuating. One possible reason for this could be attributed to the gaining of prominence by the special journal dedicated to knowledge management, Journal of Knowledge Management. Again, Table 3 reveals that 55 articles representing 50% of the total publications were published during the last 7 years, which is an indication of a rising interest and attention on knowledge sharing from researchers and practitioners.

Key methods and theoretical underpinnings
Researchers mostly used quantitative, qualitative, and mixed methods to explore knowledge management or knowledge sharing in organization (see Table 4). Fifty-five key articles are presented in Table 4 because of space, the summary of the remaining 55 articles is available upon request (Bahoo et al., 2019). Out of 110 articles, 73 (66.36%) used quantitative method through different analysis (regression or multiple regression, principal component analysis, and structural equation modeling); 33 articles (30%) were either qualitative, conceptual or review and utilized content analysis, comparative analysis, systematic literature review, and narrative review; and mixed method approach was used in four articles (3.636%).
As illustrated by Table 4 again, several theoretical frameworks have been utilized in the literature. However, only 38 papers (34.54%) applied some form of management theory in their studies (e.g., theory of reasoned action-TRA, knowledge-based view, social cognitive theory, resourcebased view theory, organizational theory, etc.). Among the theories mentioned, it is not surprising to see the theory of reasoned action (TRA) dominating because knowledge sharing is an action that requires critical reflection. TRA concerns the influence of personal beliefs and attitudes, as well as other factors specifically related to human and social exchange processes, which provide a better explanation to human behaviors (Bock et al., 2005;H. F. Lin, 2007).

Prime research streams
A careful examination and analysis of the 110 articles published in the review period reveals three distinctly but interrelated research streams in the literature: (1) knowledge sharing enablers, (2) knowledge sharing processes, and (3) knowledge sharing outcomes.

Enablers and barriers to knowledge sharing
Enablers are "the mechanisms for fostering individual and organisational learning and facilitate employee knowledge sharing (H. F. Lin, 2007) whilst barriers are the obstacles to knowledge sharing (Maitlo et al., 2019). Employees are motivated to share their expertise for different reasons: mutual benefit, trust, reward, and many others (Hau et al., 2013;Zhang & Jiang, 2015;Xue et al., 2011). There are different reasons why people are reluctant to share knowledge. For example, Szulanski (1996) pinpointed the absence of motivation on the part of the knowledge source as a major hindrance to knowledge sharing. Lack of awareness of knowledge sharing benefits, lack of social network, gender difference, status inequality, difference in educational level, have been identified as individual barriers to knowledge sharing by researchers (Khalil & Shea, 2012;Ling et al., 2009;Riege, 2005). Tamjidyamcholo et al. (2014) assert that KS barriers are more severe in larger online retail organisations than in small-and medium-sized enterprises. This review has observed that knowledge sharing enablers have been observed broadly under individual or personal factors, organizational factors, and information communication technology (ICT) factors (e.g., Bock et al., 2005;H. F. Lin, 2007;Podrug et al., 2017;Yesil, 2014) 4.5.1.1. Individual or personal factors. The review identified mutual trust and reciprocity as the most essential factors that have been mostly studied. Zhang and Jiang (2015) concluded that  (2013)    knowledge sharing depends on the quality of the relationship between the knowledge seeker and knowledge provider. However, Brcic and Mihelic (2015) argue that organizations can benefit from knowledge sharing only when workers establish a deep connection to better understand the knowledge provider's thoughts. Moreover, there is a social bond between the knowledge seeker and the provider (Anand et al., 2019). Xue et al. (2015) established that trust in the team environment influence knowledge-sharing behavior of individuals, both externally and internally. Even in the multinational corporations where distance and different cultures prevail, mutual trust and reciprocity make knowledge sharing possible (Fong & Mar, 2015). Several studies have confirmed that reciprocal knowledge exchange relationship is beneficial to knowledge contributors and promote knowledge sharing (Bock et al., 2005;Chang & Chuang, 2011;Chiu et al., 2006;Hau et al., 2013;Schultz, 2001). Another individual factor that has been studied extensively is reward and motivation. Davenport and Prusak (1998) highlighted the importance of reward mechanism to knowledge contributions given that people's time, energy, and knowledge are short in supply. Reputation is one reason that motivate employees to participate in knowledge sharing (Hung et al., 2011) because it helps the individual to obtain and maintain his or her status in the society (Marett & Joshi, 2009) and exposes dysfunctional members in a team (Hung et al., 2011). People participate in knowledge sharing because they believe that sharing knowledge can help them to establish and elevate their reputation (Wasko & Faraj, 2005) Several studies have confirmed a positive relationship between reward and motivation and knowledge sharing (e.g., Hung et al., 2011;Kankanhalli et al., 2005;Wasko & Faraj, 2005).

Organizational factors.
At the organisational level, factors that have been found to have influence on knowledge sharing include leadership, organisational culture, organisational reward systems, and organisational structure (H. F. Lin, 2007;Kim & Lee, 2006;Podrug et al., 2017;Shanshan, 2014). Top management and leadership support are essential for knowledge sharing (H. F. Lin & Lee, 2006;) and have been found to be a motivator to knowledge sharing (Cavaliere & Lombardi, 2015). This is true because empowering leadership significantly affects knowledge behaviours (Xue et al., 2011).
Contemporary research on knowledge sharing has emphasized organizational structure as an important factor that facilitates or impedes the transfer of knowledge in the organization (Asrar-Ul -Hag et al., 2016). O'dell and Grayson (1998) suggest that organizational structure should be designed to promote flexibility as a means of encouraging collaboration and sharing within and across organizational boundaries and stakeholders. Organizational structure that emphasizes centralization, rules and regulations, and control systems may serve as a barrier to the creation and sharing of knowledge (Kim & Lee, 2006). But participatory management practices balance the involvement of managers and subordinates in information-processing, decision-making, or problem-solving (Wagner, 1994).
Real and perceived rewards and penalties for individuals who share or hide knowledge influence the knowledge sharing process (Ipe, 2003). Organizational reward system shapes employee behaviour and ranges from monetary and non-monetary incentives like salaries and bonuses, promotions, and job security (Bartol & Srivastava, 2002;Davenport & Prusak, 1998). Davenport and Prusak (2000) remarked that, knowledge market has buyers and sellers who negotiate to arrive at mutually acceptable price for the goods exchanged whilst R. M. Grant (1996) also posits that knowledge sharing must be adequately compensated for. Therefore, employees are willing to share knowledge when there is adequate compensation. Saunila (2014) posits that organizational culture that provides encouragement, respect employees' ideas, gives positive feedback is helpful and facilitates creative skills and risk-taking. A strong positive organisational culture is critical to promoting learning, development and the sharing of skills, resources, and knowledge (Bollinger & Smith, 2001). Von Krogh (1998) argues that trust and openness in organizational culture promote active knowledge sharing among employees. Kim and Lee (2006) postulated that there are three components of organisational culture that are related to effective knowledge sharing: clear organisational vision and goals, (Gold et al., 2001;Kanter, 2003), trust (Cohen & Prusak, 2001;O'dell & Grayson, 1998;Von Krogh, 1998), and social networks (Leonard & Sensiper, 1998;Tsai, 2002). 4.5.1.3. Information Communication and Technology (ICT). Although, it is individuals rather than organizations who share knowledge, the use of data at the organizational level has been a common feature of most studies on knowledge sharing (Andersson et al., 2016). Okhuysen and Eisenhardt (2002) posit that knowledge is generally examined on an individual basis, however, it can be acquired, stored, and used at the organisational level through ICT (Davenport & Prusak, 1998). ICT increases knowledge transfer by extending an individual's reach beyond formal lines of communication (Alavi & Leidner, 2001). The use of ICT facilitates collaborative work and enables knowledge sharing (Yeşil & Hırlak, 2013). Hendriks (1999) identified four roles of ICT in relation to knowledge sharing: Overcoming constraints; increasing range and speed of information access; improving task performance; and using technology to identify the elements. More recently, with the advancement in ICT, more sophisticated IT tools like social media (WhatsApp, Twitter, LinkedIn), web 2.0 technologies like blogs and wikis have been highlighted in knowledge sharing (e.g., Hag and Anwar, 2019; Rathi et al., 2014) Whilst the review identified knowledge sharing enablers and barriers, extant literature has overconcentrated on individual and organisational factors that promote knowledge sharing (Jiang et al., 2016) and neglects knowledge sharing barriers (Wu and Lee, 2016;Javed et al., 2019). The above gap ought to be filled because progress in knowledge sharing theory requires an in-depth understanding not only of knowledge sharing enablers, but also barriers, so that efforts can be made to offset them (Islam et al., 2020)

Knowledge sharing processes
Knowledge sharing process refers to how employees share their work-related experience, expertise, know-how, and contextual information with their colleagues. Knowledge sharing process consist of both employee willingness to actively communicate with colleagues (i.e., knowledge donating) and actively consult with colleagues to learn from them (i.e., knowledge collecting) (H. F. Lin, 2007). Tsoukas (2009) highlighted the essence of both social practices within which knowledge is created and social interaction through which knowledge emerges. In this regard, Nonaka & Toyama (2005) proposed the socialization and externalization combination internalization (SECI) model of knowledge creation.
Trong Tuan (2012) identified face-to-face, conferences, knowledge network, and organisational learning as a way of sharing knowledge. De Ridder and van den Hooff (2004) viewed knowledge donating, knowledge collecting, and personal networking and membership as critical to knowledge sharing. On the other hand, Hau et al. (2013) argued that tacit knowledge sharing requires more effort than explicit knowledge and identified teaching or interactive learning as a way of sharing knowledge. Bartol and Srivastava (2002) identified four mechanisms for sharing knowledge, namely: contribution of knowledge to organisational databases; formal interactions within or across teams or work units; sharing knowledge in informal interactions among individuals; and sharing knowledge within communities of practice, which are voluntary forums of employees around a topic of interest. Ipe (2003) postulated that sharing knowledge in organisations could be formal or informal in nature and further explained that formal opportunities include training programmes, structured work teams, and technology-based systems that ensure knowledge sharing. Different authors refer to the formal approach to knowledge sharing differently, for example, Bartol and Srivastava (2002) regarded this as "formal interactions" whilst (Lant & Shapira, 2000;Rulke et al., 2000) referred to them as "purposive learning channels". Again, Ipe and other researchers (e.g., Brown & Duguid, 1991;Nahapiet & Ghoshal, 1998) see the informal approach as personal relationships and social networks that ensures learning and knowledge sharing. Whilst both the formal and informal approaches facilitate knowledge sharing, evidence available indicates that knowledge sharing takes place commonly in informal environment using relational learning channels (Archer et al., 1998;Pan & Scarbrough, 1999). The reason is that relational channels promote and simplify faceto-face communication, which tend to build trust (Ipe, 2003), and helps individuals to develop respectable behaviours and friendship (Nahapiet & Ghoshal, 1998).
Additionally, Ravik et al. (2016) asserts that in transferring knowledge, the instrumental translation theory is not only useful for analyzing knowledge transfer processes, but also has the potential to guide deliberate interventions in such processes. The author further stress that the instrumental translation theory is founded on two main arguments: The outcomes of knowledge transfer processes depend on "translation performance" that is, how actors apply various translation rules when de-contextualizing practices in source units and contextualizing representations of practices in recipient units; it is then possible to theorize and empirically identify appropriate and less appropriate skilled and less skilled translators in knowledge transfer. However, whether formal or informal way of sharing knowledge, knowledge is shared through a process. The knowledge-sharing process is conceptualized as a structured process (Chatterjee et al., 2022), and is aligned with the firm's strategy, available skills and competence, and guidelines to facilitate the process. Some of these strategies, processes, skills, and guidelines are industry, market, and firm specific. That notwithstanding, researchers have not investigated how any of these elements should be aligned in a particular industry or firm to ensure successful knowledge sharing.

Knowledge sharing outcome
Knowledge sharing outcome has to do with the results of knowledge sharing. Thus, how the organisation performs because of knowledge sharing. Organizational performance indicators are typically either financial/tangible outcomes or nonfinancial/intangible outcomes (Ali et al., 2019). Meanwhile, one thing that is clear about organisational performance is that it is the ability of the organisation to achieve set objectives of retaining profit, having a competitive edge, increasing market share, and maintaining long-term survival utilizing appropriate strategies (O. Oyemomi et al., 2019).
H. F. Lin (2007) viewed innovation capability as the outcome of knowledge sharing because he investigated the relationship between knowledge and innovation capability. This means that the outcome dimension can be proxied what the researcher is investigating. For instance, Podrug et al. (2017) examined how knowledge sharing affect firm innovation capability. Similarly, Yeşil and Hırlak (2013) explored the relationship between knowledge sharing enablers, innovation capability and innovation performance, and found a positive association between knowledge sharing enablers, innovation capability and innovation performance. Han and Chen (2017) also established a significant relationship between knowledge sharing and innovation performance. Additionally, Z. Wang et al. (2014) examined and confirmed a positive relationship between knowledge sharing, intellectual capital, and firm performance.
Meanwhile, there are a host of other researchers who have examined knowledge sharing and financial performance and confirmed a positive relationship between the two. For example, Yeboah (2022) investigated the relationship between knowledge sharing and financial and market performance and established a positive relationship between knowledge sharing and financial and market performance. Z. Wang and Wang (2012) studied and confirmed a positive relationship between knowledge sharing and financial and operational performance. Other researchers who have studied and confirmed a positive relationship between knowledge sharing and financial performance include but not limited to Imamoglu et al. (2007), Singh et al. (2019), and Son et al. (2020).
Even though, knowledge sharing outcome or organisational performance index are mostly either financial outcomes or nonfinancial outcomes, extant literature generally concentrates on financial outcomes. The only nonfinancial outcome that has featured in the literature is innovation or innovation capability even though the speed and quality of innovation (Wang et al., 2016a), reduction of time spent on manufacturing, designing, and delivering a product to market are also important nontangible benefits (Ali et al., 2019).

Future research directions
Literature on knowledge sharing is well established in the context of developed economies. However, it is relatively unexplored in the emerging and developing world, especially, in the sub-Saharan Africa. Irrespective of the work done on knowledge sharing, there is still much to be explored to move knowledge sharing to the next level.
Generally, the review identified different definitions and types of knowledge. That notwithstanding, the definitions exhibited three main characteristics: knowledge sharing is a process and not an event; it involves willingness to donate and receive an accumulated expertise; and is geared towards finding solution to organizational problems or generating new ideas. In going forward, different definitions are expected to emerge, but expected to conform to the characteristics identified. Regarding the types of knowledge, extant literature is silence on the kinds of knowledge that better contribute to develop the competencies required to enter specific market (Magni et al., 2022). Therefore, further research is required to identify the kinds of knowledge relevant for the development of competencies and skills for specific customers/clients, industry/market, and economies. This is very essential because of the differences in environmental and cultural factors. For example, the type of knowledge required to develop the competencies in dealing with customers from the service industry in the developed or developing countries.
With respect to knowledge sharing enablers and barriers, available evidence indicates abundance of studies on knowledge sharing enablers at the expense of knowledge-sharing barriers. Consequently, future studies must focus more on the barriers that hinder knowledge sharing instead of knowledge sharing enablers. This must be looked at in relation to the individual, organisational and ICT factors. For example, on the individual factors, how strained ties among employees or how individuals position in the organisation impede knowledge sharing could be investigated. How managers experience or abusive leadership hinders knowledge sharing could be examined at the organisation level. Additionally, how lack of investment in technology hinders knowledge sharing in the emerging markets is another avenue for research.
Although knowledge sharing is successful when the process is aligned with the firm's objective, strategy, available skills and competence, no study has examined the challenges firms encounter when knowledge sharing process is not aligned with any of the elements identified. Even though, K. A. Bavik (2016) argues that knowledge sharing is rule-based translation process. Some of these strategies, processes, skills, and guidelines are industry, market, and firm specific therefore, studies could be conducted to find out the kind of processes or guidelines relevant to a particular industry or market to facilitate knowledge sharing.
Moreover, even though knowledge sharing outcomes are mostly either financial or nonfinancial, extant literature generally concentrates on financial outcomes. Innovation or innovation capability is the only nonfinancial outcome examined regularly in the literature. Therefore, further research should be conducted to find out how knowledge sharing influences other nonfinancial outcomes.
For instance, how knowledge sharing affects ethical behaviour and sustainability in emerging market oil and gas industry.
Generally, the review indicates that most of the research were conducted in commercial entities with few in the public sector. One setting that will be interesting to explore how knowledge is shared will be the various bodies of government especially, the legislative arm. Knowledge sharing is very essential in the legislative arm because it will give members the opportunity to know and understand parliamentary proceedings and rules, language, the committee system, and the standing orders. However, with the whip system in place to defend and promote political party interest, how members across the various political parties share knowledge to promote effective parliamentary proceedings will be an interesting topic to investigate, especially, in Africa and other emerging countries.

Conclusion and implications
Although several reviews on knowledge sharing have been conducted to get a better understanding of the concept, because of the essential role it plays, till date, no review has looked at articles in the light of prime research streams, contextual positions, and influential journals at the same time. This review was conducted to bring together scattered literature on knowledge sharing and scrutinize them to provide a better understanding of knowledge sharing and suggest emerging directions for future research. The paper has not only confirmed the importance of knowledge sharing in the competitive environment, but it has also identified gaps in knowledge and offered suggestions to close these gaps and move the concept forward. The findings (gaps) identified thus, provide a platform for further research into not only how to share knowledge but how to overcome the barriers to knowledge sharing to enjoy the benefit thereof.
The findings and suggestions made provide policymakers with an opportunity to identify the type of knowledge that is essential to develop staff competence in the various industries and markets. With this information, policymakers will be able to formulate appropriate policies and legislation to support both private and public companies to develop the needed skills to compete in the global market. For example, being aware of the kind of knowledge needed will enable the government (policymakers) to determine the kind of resources: equipment/tools, incentives and consultancy service offered to innovative firms.
Additionally, the findings and recommendations of this paper also offer managers and practitioners the chance to find out the type of knowledge required to develop their employees' competence for their industry and market needs. This paper findings will equip managers with the intelligence to design their knowledge sharing processes in line with their overall business objective and strategy to facilitate smooth sharing of knowledge. Knowing the knowledge requirement, not only will managers be able to determine whether knowledge sharing should be internal or external, it will also afford them the opportunity to identify the kind of training needed to build employee competence, as well as the investment need to update knowledge sharing infrastructure.
Meanwhile, knowledge sharing enablers, processes and outcomes are interlinked, with each other affecting the other in a linear fashion. Therefore, for knowledge sharing to be successful, the right knowledge must be identified and shared by people willingly. It must also be shared in a manner, which is consistent with the business objective and strategy, guided by appropriate guidelines. Before the full or expected outcomes will be enjoyed.