Service research: past, present and future research agenda

Abstract

Purpose

This study aims to explore past and present service research and to provide a future research agenda for service researchers by presenting a big picture of the intellectual connections and emerging topics in the discipline.

Design/methodology/approach

This study is an empirical analysis of citations and cocitations on a sample of 5,837 articles published in leading service journals (from 1981 to December 2020). Network analysis was adopted to analyze the data. This study is exclusive in conducting the inquiry at the individual publication level, rather than using the normal aggregated author co-citation analysis approach.

Findings

The findings reveal that the main themes of service research centered on customer satisfaction, service quality, service-dominant logic, methodological foundations, market orientation and service encounter. Also clarified is the periphery domain that may become more important in the future (i.e. technology). The findings also present anchor points for conceptual framing and conceptual development – five main themes that are momentous to navigate theory discovery and justification in the knowledge domain.

Research limitations/implications

It calls for a more academic effort to evaluate the service research by considering different epistemological paradigms, such as positivism, monologic and hermeneutic, to better understand the process and progress of the discipline.

Practical implications

Through exploring the transformation of service research into a customer-centric model and technology-based service logic, this study offers possible implications for practitioners and further research areas for service researchers.

Originality/value

To the best of the authors’ knowledge, this study is the first to use a citation, cocitation and network analysis to examine service research published in leading service journals. This study provides a significant contribution to the theory by combining main conceptual areas and interests in the given discipline.

Propósito

Este estudio explora la investigación de servicios pasada y presente y proporciona una agenda de investigación, presentando un panorama general de las conexiones intelectuales y los temas emergentes en la disciplina.

Metodología

Este estudio es un análisis empírico de las citas y co-citas sobre una muestra de 5.837 artículos publicados en las principales revistas de servicios (1981–2020). Se utilizó el análisis de redes para examinar los datos. Este trabajo es único en la realización de la investigación a nivel de publicación individual, en lugar de utilizar el enfoque habitual de análisis de co-citación de autores agregados.

Conclusiones

Los resultados revelan que los temas principales de la investigación sobre servicios se centran en la satisfacción del cliente, la calidad del servicio, la lógica del servicio dominante, los fundamentos metodológicos, la orientación al mercado y el encuentro de servicios. También se clarifica un ámbito periférico que puede adquirir mayor importancia en el futuro (la tecnología). Los resultados también presentan puntos de anclaje para el encuadre y el desarrollo conceptual de diversos temas importantes.

Originalidad

Este estudio es el primero que utiliza un análisis de citas, co-citas y redes para analizar la investigación en servicios publicada en las principales revistas de servicios. Proporciona una importante contribución a la teoría al combinar las principales áreas conceptuales y los intereses de la disciplina.

Implicaciones prácticas

Mediante la exploración de la transformación de la investigación en servicios en un modelo centrado en el cliente y en la lógica de los servicios basados en la tecnología, este estudio ofrece posibles implicaciones para los profesionales y nuevas áreas de investigación para los investigadores.

Implicaciones

Se reclama un mayor esfuerzo académico para evaluar la investigación de servicios considerando diferentes paradigmas epistemológicos, como el positivismo, el monologismo y la hermenéutica, para comprender mejor el proceso y el progreso de la disciplina.

目的

本研究旨在探索过去和现在的服务研究, 并通过展示该学科的知识联系和新兴主题的全局, 为服务研究领域的学者提供未来的研究议程。

设计/方法/途径

本文是基于1981年到2020年12月期间发表在五个领先服务类期刊上的5,837篇文章进行引用和共同引用的实证分析, 并采用网络分析法对数据进行分析和分类。这项研究的独到之处在于在单个出版物层面上进行调查, 而不是采用正常的汇总作者共被引分析方法。

研究结果

我们的调查结果显示, 服务研究的主题主要集中在顾客满意度、服务质量、服务主导逻辑、方法论基础、市场导向和服务遭遇。同时, 还阐明了未来可能变得更加重要的外围领域（即技术）。研究结果还提出了概念框架和概念发展的锚点–概念图的五个主要主题对导航知识领域的理论发现和论证至关重要。

原创性

本研究首次使用引文、共同引文和网络分析来考察发表在领先服务期刊上的服务研究。它结合特定学科的主要概念领域和兴趣, 为理论研究做出了重要的贡献。它还确定了我们在服务学术研究中已知和未知的内容。

实践意义

通过探索服务研究转变为以客户为中心的模式和基于技术的服务逻辑, 本研究为从业者提供了启示, 也为后续服务研究指引了值得进一步研究的领域。

研究局限/意义

本文呼吁更多的学术研究通过考虑不同的认识论范式, 例如实证主义、一元论和解释学来评估服务研究, 以便更好地了解该学科的过程和进展。本文还呼吁未来研究可以尝试填补本文研究结果提出的知识空白。

Citation

Arici, H.E., Köseoglu, M.A. and Altinay, L. (2022), "Service research: past, present and future research agenda", Spanish Journal of Marketing - ESIC, Vol. 26 No. 2, pp. 146-167. https://doi.org/10.1108/SJME-09-2021-0177

1. Introduction

How does scientific service research evolve? To unearth this black box, we need to address another question: “what is the origin of academic service research?” The origin aids to form the intellectual links and consequently the structure of the scientific field (Köseoglu et al., 2021). Visualization of the intellectual relations contributes to proposing and developing novel and current approaches. Revealing potential structures and solving existing questions could offer knowledge and possible remedies for industry professionals (Köseoglu et al., 2021). In addition, scientific domains have used identifiable intellectual connections that form further directions. Service research demonstrated a proof of evolution, starting with the discussion of services marketing as a separate field from product marketing and its definition as a unique scientific domain (Lovelock and Patterson, 2015; Parasuraman et al., 1985; Shostack, 1977). An academic understanding of this progress could be significant for scholars, who try to clarify the prospective influences of theory on the industry. Revealing interconnections among various service industries could also provide a meaningful contribution to practitioners about past, present and future trends in the service context.

Scholars have conducted empirical studies of evolution by focusing on specific service sectors, including hospitality (Arici et al., 2021), education (Tight, 2008), health care (Rigby, 2014) and marketing (Sheoran et al., 2018). However, these investigations have not provided a comprehensive view of the evolving patterns of the service literature. Therefore, there is a need for research that clarifies the origins, progress and topics of the scientific service references in an examination for intellectual connections, also known as intellectual structure, cocitation networks, invisible colleges, knowledge networks, knowledge domains or source knowledge that is a depiction of a discipline’s theme-based features from its roots to its roof (Köseoglu, 2020).

The specific reasons for such an empirical work are threefold. The first and foremost reason is the maturity level of the service research literature. Recent academic debate has also escorted the development of service research. It is noteworthy that there is a current discussion on service delivery design in service industries. Integration of new-generation technologies, for instance, has adopted philosophical viewpoints from determinism and instrumentalism to define technology as autonomous and humanly controlled as a response to the traditional design of service context. This alternative view has also been triggered by academic efforts, particularly after the recent COVID-19 pandemic. Developing a novel approach requires realizing what the origin tells us. Therefore, examining the scientific root of complete service research deserves scholarly attention, different from performing tantamount research within a specific discipline, like hospitality. Even though service literature has a thriving background, past investigations have provided scarce longitudinal scope that leads to producing an inadequate understanding of the progress of the scholarly domain over the longer run. The other reason for such empirical work is because of the restrictions of previously conducted bibliometric analyses in the service literature. Previous investigations neither conceived intellectual connections between appearing studies or subdomains nor the transformative effect of influential studies across the complete service research domain (Köseoglu et al., 2021). Third, recent bibliometric studies have merely focused on analyzing a historical evolution of a single journal (Donthu et al., 2020; Tur-Porcar et al., 2018). Moreover, several scholars have considered it a unique sector and a territory (Rigby, 2014). These attempts have of course provided a meaningful contribution to the knowledge, but they fault revealing a complete big picture of service literature because a greater wide bibliometric research could potentially create more generic outcomes.

Last, past investigations have generally included not only journal articles as a way of a credible sources but they also used books, book chapters, conference papers, dissertations and research notes to expand their citation and co-citation analysis. Despite its limited advantages, this method can create problematic empirical results (Köseoglu et al., 2021). To illustrate, conference papers might be not submitted to a rigorous review process that leads to a question regarding their presented findings, if they are contrasted with academic journal articles.

Considering this background, this study fills the aforementioned knowledge gaps regarding the state-of-the-art in service research by using a quantitative examination of articles published in the leading service journals. Hence, this study performs bibliometric analysis (i.e. citation, cocitation) accompanied by network analysis to present a wider and deeper understanding of intellectual structure in service literature. In portraying these links, this present work has the following specific purposes:

• to define influential fields of source knowledge in service literature by mapping the intellectual connections;

• to decide on main connections and clusters within the knowledge domain; and

• to display appearing study fields as a possible agenda for further research.

The contribution of this present research to the service literature is threefold. One is a contribution to the theory development in service research. This is achieved through the establishment of intellectual structure across a large body of investigation. Second, this present research includes a larger number of service journal articles over a longer time horizon than its counterparts. This may enable service scholars to gain a wider insight into the domain and its progress over an extended period. In particular, the results could illustrate what we know to extend our current knowledge of service scholarship and what we do not know to reveal the knowledge gap within the domain. Finally, because using academic journal articles could provide more reliable outputs in a bibliometric study (Köseoglu et al., 2021), this paper merely includes journal articles in the analysis. In doing so, this study has a great potential to produce evidence-based results and future directions from reliable data sources.

2. Intellectual structure of service research

Several scholars have conducted review analysis in the service literature. These studies could be categorized into three clusters. The first cluster includes service-focused investigations (Arici and Uysal, 2022; Benoit et al., 2017; Cronin, 2003; Gürlek and Koseoglu, 2021; Subramony et al., 2021). Using keywords “service” and “employee,” Subramony et al.’s (2021) study consisted of articles associated with frontline service employees in applied/occupational health psychology and service journals. Benoit et al. (2017) also used limited criteria, including theory, methodology and some descriptive aspects (e.g. number of authors or references).

The second consists of journal-focused studies (Donthu et al., 2020; Donthu et al., 2021a, 2021b; Pilkington and Chai, 2008). Pilkington and Chai’s (2008) study revealed core research themes and concepts of the International Journal of Service Industry Management, whereas Donthu et al.’s (2020) co-citation analysis identifies the Journal of Service Research’s (JSR) prominent topics and traces the progress of the study themes in the journal. Similarly, other recent bibliometric studies focus on revealing the intellectual structure of a specific journal, instead of a discipline. Donthu et al.’s (2021a) work examined the source knowledge of the Journal of Services Marketing (JSMAR) and Donthu et al.’s (2021b) study revealed the themes of the Journal of Service Theory and Practice (JSTP).

The third and last cluster can be named theme-focused (Gong and Yi, 2021; Klaus and Zaichkowsky, 2020). Gong and Yi (2021), for example, focus on only customer citizenship behaviors, whereas Klaus and Zaichkowsky’s (2020) study investigates artificial intelligence (AI) in the field of services marketing. Though these previous attempts have contributed to the service research, they mostly fail to provide a wider view of the intellectual structure of the knowledge domain. Thus, our paper has the potential to make a considerable contribution to the service literature by not only revealing the past and present of the service research but also providing future research agenda for further scientific efforts. Table 1 provides the past review research investigating the intellectual structure or knowledge networks in service research.

3. Methodology

This study adopts citation analysis and co-citation analysis through network analysis to investigate the intellectual structure of service research. These methods enhance the objectivity of findings obtained, with the inclusion of big datasets over a large period. Citation analysis includes clarifying main documents in a knowledge field through computing references. It presents applicable outcomes regarding the past and future of a domain. Subsequently, co-citation analysis investigates associations among the influential articles by visualizing source knowledge in the discipline. These methods help scholars to reveal emergent subdomains and their intrarelationships. Hence, this paper sets out to explore the intellectual connections of service research by using cocitation and network analyses.

3.1 Data collection

The data analyzed consists of references cited by service associated articles, which have been published in scientific journals. These articles were obtained from the five highly prestigious service journals: The Service Industries Journal (TSIJ), Journal of Service Management, JSMAR, JSR and JSTP. In the selection of these journals, we first searched the most well-known international databases (i.e. Social Science Citation Index and Scopus) and decided on five leading service journals. Another reason behind choosing these journals is their higher impact factors than other service journals. In other words, these five journals have published the most cited articles in service research, thus their potential to dominate the knowledge field is higher than their counterparts. To check the applicability of the selected journals, two productive scholars and a service journal editor have also been advised. Through getting their approval, the five journals have been included in the study sample.

We downloaded articles and their reference lists from the Scopus database from the first issue to the latest issue in 2020. Among these five journals, as the first academic service journal in the world TSIJ’s first issue was released in 1981. Our bibliometric analysis thus includes journal articles published from 1981 to December 2020. The data were transformed into an Excel sheet, including a total of 5,837 articles with a reference list. To enhance the reliability of the study findings, we decided to consider only articles from the references and so excluded books, book chapters, conference papers and dissertations. This process resulted in approximately 250,000 journal reference appearances.

3.2 Analysis

In bibliometric analysis, four main methods have appeared (i.e. actor analysis, cluster analysis, multidimensional scale analysis and network analysis), each of which relies on co-citation analysis to reveal the intellectual connections of a knowledge domain (Köseoglu et al., 2021). Despite its huge importance in the bibliometric literature, co-citation analysis has still suffered from the lack of a widely accepted threshold value (Hota et al., 2019; Köseoglu, 2020). While several scholars use cutoff criteria for the analysis (Hota et al., 2019), other researchers adopt the trial-error approach, and the rest follow a threshold value that consists of a minimum of 50, 100, or greater studies based on study choice and specialty (Köseoglu et al., 2021). Drawing on the debate, we decided to use the most cited 100 articles as a threshold value in this study. This leads to 100 articles that were cited at least 96 times for potential examination with 19,628 appearances.

In this paper, we performed network analysis to visualize the scholarly foundations and main themes like clusters through VOSviewer software. This software clarifies clusters by using modularity-based clustering (Eck et al., 2010). We then adopted the relationship strength approach for purposes of normalization. In the network visualization, circles present nodes and lines depict the links between the nodes. The colors show the clusters to which the nodes belong. The magnitude of the nodes demonstrates the usage frequency of an article as a reference (Köseoglu et al., 2021).

4. Findings

4.1 Citation analysis in service research

By using document citation analysis of references of the studies issued in the five service journals, influential studies have been revealed in the service research. This study considers the most cited 30 service research articles. The top ten articles have provided several viewpoints regarding influential studies in the field. In terms of topic, SERVQUAL appears as a leading topic in the first (Parasuraman et al., 1988), third (Parasuraman et al., 1985) and fifth most cited articles (Zeithaml et al., 1996) written by the same research team. Cronin Jr and Taylor’s (1992) study on service quality is another paper among the top ten most cited articles. Vargo and Lusch’s (2004) seminal work suggesting an evolution of marketing dominant logic from firm-centric value creation to customer-centric value creation appears as the most cited fourth article in the service research. Bitner et al.‘s (1990) pioneering work on service encounters is another of the top ten most cited articles, followed by Morgan and Hunt’s (1994) commitment trust theory. Though it cannot be argued that the findings represent comprehensive knowledge domains in the service research, it can be concluded that SERVQUAL is the leading topic and theoretical framework within the service research, followed by customer-centric models in the service encounter.

In terms of methodology, the most cited study is Fornell and Larcker’s (1981) seminal work on structural equation modeling (SEM). This is followed by Anderson and Gerbing (1988) on the same method (i.e. SEM). Podsakoff et al.’s (2003) work is another influential methodology-focused paper that appeared as the tenth most cited article in service research. This finding illustrates the dominance of quantitative methods, particularly SEM, in service research.

4.2 Co-citation analysis in service research

Drawing on document co-citation analysis, this study reveals five unique clusters, each presenting a knowledge domain of the service research (see Figure 1). Appendix demonstrates the relevant data regarding the unique clusters and their ingredients. To appropriately label each cluster, this study has performed a qualitative examination of citations in clusters.

4.2.1 Customer satisfaction and customer relationship.

Customer satisfaction and customer relationship is the biggest theme (red colored) with the highest volume of ingredients (see Figure 1). The suggested label considers two subdomains to identify the foci of studies within the theme. The largest categorizing studies with the highest weightings concentrate on customer satisfaction. An obvious association between service quality and satisfaction has appeared in this cluster. The most influential study is Zeithaml et al.’s (1996) work that develops a conceptual model of the effect of service quality on particular behaviors that signal if customers are satisfied or dissatisfied with the service provided by a company. Another influential article within this cluster is Oliver’s (1980) pioneering work, which proposes a model expressing customer satisfaction as a function of expectation and expectancy disconfirmation. In line with Zeithaml et al.’s (1996) model, the author suggested that satisfaction influences customer purchase intentions. Customer defections have also been expressed as a consequence of dissatisfaction in service organizations (Reichheld and Sasser, 1990). The authors addressed that customer defection could tell service organizations what parts of the business must be improved.

Fornell’s (1992) study concentrated on a national level of customer satisfaction barometer. His work revealed that Sweden is the first country to develop a national level satisfaction barometer. This national-level barometer measures quality of the total consumption process as customer satisfaction. Within the same country (i.e. Sweden), the other influential study was conducted by Anderson and Sullivan (1993) to reveal the antecedents and consequences of customer satisfaction. Another influential article confirms that the most influential customer satisfaction studies were conducted in Sweden (Anderson et al., 1994). The authors investigated the financial outcomes of ensuring customer satisfaction in organizations.

Customer relationship-focused studies constitute a second subdomain in this theme. Morgan and Hunt’s (1994) seminal study is the most influential customer relationship reference. The authors theorized that successful relationship marketing requires relationship commitment and trust. Crosby et al. (1990) developed and examined a relationship quality model, which analyzes the nature, outcomes, and predictors of customer relationship quality. The authors revealed that customer relationship quality, including trust and satisfaction, significantly influences companies’ future sales opportunities.

Other influential references in this cluster have examined the role of trust (Doney and Cannon, 1997; Garbarino and Johnson, 1999; Sirdeshmukh et al., 2002) and satisfaction (Bolton, 1998) in the buyer–seller relationship. Doney and Cannon’s (1997) work developed a theoretical model that addresses the importance of the trust in the supplier, salesperson and buyer relationship and found that trust of the supplier firm and trust of the salesperson affect a buyer’s anticipated future interaction with the supplier. Moreover, Garbarino and Johnson (1999) revealed that for the high relational customers, trust and commitment play a mediating role in the relationship of component attitudes and customer future intentions. Sirdeshmukh et al. (2002) also developed a model for comprehending the service providers’ policies and implications that improve or deplete customer trust and the mechanisms that transform customer trust into value and loyalty in relational exchanges. On the other hand, Bolton’s (1998) work revealed that customer satisfaction ratings are positively associated with the duration of the relationship. Overall, influential studies have put a special emphasis on trust to investigate customer relationships.

4.2.2 Service quality and servicescape.

As seen in Figure 1, the second knowledge domain combined with influential service marketing-focused sources is placed toward the bottom left side of the cluster map (green-colored). The fundamental foci of articles within this theme are associated with service quality and servicescape. Whilst Grönroos’s (1984) article is the first academic attempt to clarify the service quality concept and its marketing practices, Parasuraman et al.’s (1988) SERVQUAL scale dominates this cluster. Their seminal work evolved the service quality into measurable and utilizable by future researchers. In a similar vein, the same author team conceptualized the service quality concept in their earlier study (Parasuraman et al., 1985), which is the second most influential article in this cluster. A subsequent influential study by Cronin and Taylor (1992) discussed the current theorizations of service quality phenomenon for purportedly confounding satisfaction and processed to suggest a substitute approach to test the phenomenon, called “a performance-based method.” The researchers demonstrated that the service performance scale excels service quality scale. Moreover, Zeithaml’s (1988) theoretical framework about associations of customer perceptions of service quality, price and value is among the ten most cited studies and empirically supports the interrelationship of these concepts.

The SERVQUAL concept has been theoretically and operationally described based on the gap between customers’ service quality perceptions and expectations. Service quality has widely been considered an active concept and an action of two kinds of prediction: what will and needs to happen (Boulding et al., 1993). Academic efforts have proceeded to refine, redesign and develop the measurement scale and model of the service quality concept.

The concept of servicescape is the second knowledge domain of this cluster. Bitner and his coauthors significantly contribute to the knowledge field (Bitner, 1990, 1992). As a most influential reference, Bitner’s (1990) work evaluates the service encounter where the customer interacts directly with the service provider. The author synthesizes consumer satisfaction, services marketing and attribution concepts. As the second most influential study, Bitner (1992) suggested a theoretical model for comprehending environment-user associations in service businesses.

Unsurprisingly, this cluster involves several articles that use an operational model, because servicescape is an environment where service delivery processes exist. Amongst the earliest works, Chase’s (1978) seminal study proposes a service model claiming that the less direct customer contact in service delivery, the greater the potential of the system to operate at peak efficiency. Shostack (1984) proposes a service blueprint model that enables a service organization to discover all the issues inherent in generating or designing a service. The same author’s earlier conceptual study provided various market-inspired thoughts on the development of new services marketing approaches and the progress of related services marketing principles (Shostack, 1977). Solomon et al.’s (1985) pioneering work also develops a model based on the role theory suggesting that a dyadic relationship between service providers and customers is a significant factor affecting customer satisfaction with the service offered. Moreover, Zeithaml et al.’s (1993) study proposed a conceptual framework suggesting the nature and antecedents of customer expectations.

4.2.3 Service dominant logic: value creation.

The darker blue-colored cluster compounds influential service references that concentrate on service-dominant logic including value creation and is located on the right side of the map (see Figure 1). Vargo and Lusch(2004, 2008) are two authors who contributed to the two most influential references in this cluster. Vargo and Lusch’s (2004) service-dominant logic suggested that consumer inclusion in value cocreation is important to the execution of service logic. The authors show evolving of a new dominant logic for services marketing from a good-centered model of exchange. Prahalad and Ramaswamy (2004) evaluate and discuss the meaning process of value creation and evolution from a good-centric approach to a service-centric approach. They define a shift to personalized customer service that includes the cocreation of value via personalized interactions based on how each customer wishes to interact with the firm. This study emphasizes dialog, access, risk–benefits and transparency as the base of the consumer-company interaction.

Later, Vargo and Lusch (2008) identified the salient issues related to their introductory article for what has become known as the “service-dominant logic of marketing (i.e. Vargo and Lusch, 2004) and updated the original foundational premises. Similarly, this knowledge domain includes several studies, which extend and update service-dominant logic to develop knowledge of service exchange and value cocreation. Payne et al. (2008) proposed a model that presents a structure for customer participation and considers customers as the same degree of significance as the business as cocreators of value. Edvardsson et al.’s (2011) study criticized the service-dominant logic and suggested several concepts from social construction theories, such as social structures, social systems, roles, positions, interactions and reproduction of social structures. Grönroos and Voima (2013) also contribute to the development of service-dominant logic in the service literature. The authors classified the company and customers’ actions (i.e. provider, joint, customer) and their interactions (i.e. direct and indirect), resulting in various forms of value creation and cocreation in the service context. The most prolific authors of this cluster, Vargo and Lusch (2016), modified service-dominant logic by considering institutions and axioms. The authors evaluate and develop an understanding focusing on the role of institutions and institutional arrangements in systems of value cocreation: service ecosystems.

Because of the customer-focused nature of the service-dominant logic, customer engagement is another influential reference within the knowledge domain. Van Doorn et al. (2010) propose the concept of customer engagement behaviors, which is defined as the customers’ behavioral manifestation toward a brand or company. The authors articulated that companies could execute customer engagement behaviors by taking a more integrative and extensive method. Brodie et al. (2011) also discuss the role of customer engagement in cocreating customer experience and value. This study suggests that customer engagement “reflects a psychological state; occurs within a dynamic, iterative process of service relationships that cocreates value”; plays a central role within a nomological network; is a multidimensional concept; and occurs within a specific set of situational conditions generating differing customer engagement levels” (Brodie et al., 2011, p. 258).

As a changing and growing way, customers interact with companies to create service value, technology also proceeds to gradually become a critical topic in this theme. For instance, Meuter et al.’s (2000) study examines customer interactions with technology-based self-service delivery options. Bitner et al.’s (2000) work also examines the transforming nature of service, with a focus on how service logic could be developed by effectively using technology. The authors proposed and analyzed the technology infusion matrix including customization/flexibility of service, effective service recovery and spontaneous delight to customers. To comprehend this technology-based changing landscape in service logic, Ostrom et al.’s (2015) recent study provided several service research priorities, such as using big data, stimulating service innovation, understanding value creation and leveraging technology to advance service. These studies show that service research inclines to focus more on the usage of technology in customer service.

Two theory development studies have also fallen into this cluster. First, Eisenhardt’s (1989) study, which is amongst the earliest papers in theory development describes the process of theory building from case studies. The second most influential study (i.e. Barney, 1991) suggested that service firms need to possess physical, human and financial resources and these resources must be valuable, rare, imperfectly imitable and unsubstitutable. The reason these two papers have been involved within this cluster could be related to the development of new approaches for the service context. That is, service-dominant logic proposes a shift in service delivery from firm centric to customer centric and scientific efforts have continued to theorize this transformation in service research.

4.2.4 Methodology and market orientation.

As exhibited in Figure 1, the fourth cluster combines influential methodology and market orientation-related references (noted in yellow). The largest category with the highest weights emphasizes SEM in this cluster (Anderson and Gerbing, 1988; Bagozzi and Yi, 1988; Fornell and Larcker, 1981a). Podsakoff et al.’s (2003) study is also placed among the most influential articles within the knowledge domain. The authors developed statistical (i.e. Harman’s one-factor analysis) and procedural remedies (i.e. using time-lagged data) to control common method bias. Studies within this domain that possess similar emphasis but a lesser influence consist of the study by Hu and Bentler (1999) on cutoff criteria for fit indexes used to test model fit, Podsakoff and Organ (1986) on self-reports in organizational research, Fornell and Larcker (1981b) on interpretative statistics in SEM, Armstrong and Overton (1977) on nonresponse bias and Baron and Kenny’s (1986) on moderation and mediation analysis in social psychological research.

Two articles within this knowledge domain also emphasize scale development (Churchill, 1979; Gerbing and Anderson, 1988). Narver and Slater’s (1990) study also develops a valid measure of market orientation and tests its positive impact on a firm’s financial performance. This cluster endorses that service research mostly benefits from empirical analysis through conducting quantitative research methods.

Market-orientation-related studies constitute a second subdomain within this cluster. Kohli and Jaworski’s (1990) study reviews extant literature and knowledge about market orientation and presents a foundation for further investigation. Similarly, Jaworski and Kohli (1993) examined the antecedents and consequences of market orientation. This study found the significant effect of market orientation on the financial profitability of organizations.

Customer perception of service quality also plays a part in this theme. Schneider and Bowen’s (1985) examination of employee and customer perception of service quality in banks replicated and extended Parkington and Schneider’s (1979) previous work on the associations between employees and customers in service firms. The authors found a significant relationship between employees’ perception of human resources practices and customers’ reactions to the service offered. Finally, Hartline and Ferrell (1996) suggested that to improve customers’ perception of service quality, supervisors need to enhance employees’ self-efficacy and job satisfaction and mitigate their role conflict and ambiguity in the service setting.

4.2.5 Service encounter.

Figure 1 demonstrates that the last theme in light violet color unites articles on service encounters and customer complaints. Of the seven articles, three are related to service encounters, whereas the rest are related to customer complaint behaviors and experiences. The most cited article within the theme belongs to Bitner et al. (1990). The authors depicted types and classes in service design based on their consequences. Smith et al. (1999) also developed a conceptual model of customer satisfaction with service failure/recovery encounters based on an exchange framework. Using a mixed-design experiment from two service contexts (i.e. restaurants and hotels), the authors revealed that customers choose to receive recovery resources, which match the kind of failure they confront in amounts that are congruent with the weight of the failure appearing. Bitner et al.’s (1994) study explored the sources of satisfaction and dissatisfaction in service encounters from the contact employee’s perspective. The authors revealed that customers will be likely to blame the employee for a service failure caused by their misbehaviors.

Customer behavior also plays a significant role in this knowledge domain. Keaveney’s (1995) exploratory study identified approximately 80 critical behaviors of service organizations leading to customers switching services. The authors also classified customers’ reasons for switching services into eight general groups: pricing, inconvenience, core service failure, service encounter failures, response to a service failure, competition, ethical problems and involuntary switching. Tax et al. (1998) also revealed that customers were likely to have favorable responses to encounters in which initial service failures were followed by effective recovery. Interestingly, this study found that a poorly handled complaint hurt trust among current guests just as much as it did among first-time guests.

5. Conclusions, future research agenda and limitations

This study aims to investigate the intellectual structure of service research. This chapter emphasizes the theoretical contributions of this current work for the five revealed clusters and provides directions for further investigations. A preliminary and important characteristic of the highly cited documents in service research is the predominance of SERVQUAL over other concepts and approaches. This paper contributes to academic debates regarding popular service marketing theories. SERVQUAL is revealed as the most extensively accepted theory. The predominance of this theory citation demonstrates the vitality of quality as a service research theme. A comparative study examining whether SERVQUAL is a prevalent concept in all service industries would pay dividends.

Second, this present work contributes to academic debates on the breadth and dimensions of the service literature. Of the five explained knowledge domains, four could be called services marketing themes (customer satisfaction and relationship, service quality and servicescape, service-dominant logic and the service encounter). This is consistent with Javalgi et al.’s (2006, p. 13) study, suggesting “the crucial importance of services market research in service settings.” These scholars claimed that marketing research is a key mechanism through which service organizations realize their present and future customers. This present work confirms these authors’ main argument. Considering this key philosophy, naturally, customer satisfaction is the fundamental outcome of the service domain like similar services marketing variables (i.e. market orientation, value creation, cocreation and service encounter).

Third, our study has explored important voids in its clarification of knowledge fields in service research. Service research could be comprehensively studied by adopting various epistemological perspectives to better comprehend service exchange, value cocreation and service designs and encounters. By considering various paradigmatic positions or comparing findings from investigations using various paradigms, researchers could develop the service research discipline (Tronvoll et al., 2011). Though it cannot be claimed that this study completely mirrors all published service research, the analysis has demonstrated that study domains and the majority of their ingredients suit what could prevalence be considered as “positivistic research” (e.g. service quality, customer satisfaction and customer relationship), whereas monologic or hermeneutic paradigmatic articles and knowledge domains are largely absent (e.g. service-dominant logic, service encounter). Tronvoll et al. (2011) suggest that this predominance of positivistic studies has narrowed down the enrichment of the service research discipline. Thus, service scholars need to enrich service research beyond the positivistic approach to better comprehend the process and progress of the discipline. The dynamic nature of service management and marketing leads to more complex and nonstatic transactions, thus examining a topic or concept often requires various epistemological paradigms to comprehend the relevant phenomena completely. Persisting to use a limited paradigmatic way in the long term, the knowledge field might risk becoming marginalized, because of its complicated, human-interactive and relational characteristics. Thus, future service researchers can follow different paradigmatic points of departure, which can result in the enrichment of novel concepts to both conceptual and practical themes.

Fourth, our study reveals the progress of the service research, with the appearance of technology as a new and critical topic within the knowledge domain. This topic is different in its longevity because it includes the recently published most cited articles. As a shifting and increasing path customers interact with companies to create service value and exchange, service research evolves into a technology-focused domain. Even though this field recently has the smallest number of constituents, the advent of the internet and enrichments in the new-generation technologies, such as AI and service robotics, encourage service scholars to conceptually and empirically analyze the usage of technology in service research. Altinay and Arici (2021) have recently suggested a transformation of services marketing structure in the postpandemic world. The authors proposed new generation technologies as a substitutional actor in services marketing. Considering the transformation of services marketing structure in the postpandemic world, is it possible that technology can be a new actor within the service-dominant logic? Does this field provide the potential to transform mainstream disciplines? Or, may this trend appear as a unique and different knowledge field that requires special concern, such as services marketing or customer behaviors in the discipline?

Our paper has contributed to these knowledge fields by exploring their conceptual foundations. The first and foremost cluster includes studies focusing on customer satisfaction and customer relationships. Most documents in this domain emphasized customer satisfaction as an important concept for achieving service firms’ profitability. Topics of interest consist of recommendation of the service company, remaining loyal to the company, spending more time money and customer repurchase intentions, deriving from customer satisfaction with the service quality. Customer relationships also appeared as a subcluster within this knowledge domain. This cluster includes articles focusing on relationship quality between customers and service providers. Trust appears as a significant concept in the customer relationship. The customer–company relationship can be expanded by future scholars who could investigate customers’ priorities, main needs and expectations in the postpandemic world, because the recent pandemic may transform customers’ behaviors, attitudes and beliefs.

Recent studies have suggested a mixed-service approach that includes both human and technology-oriented service designs to meet customers’ changing needs and expectations in the new world (Altinay and Arici, 2021). Future research could accelerate these recently developed efforts by proposing novel industry-specific models and frameworks in service research.

One extensively investigated services marketing-focused cluster relates to SERVQUAL, a concept and a measure that has been considerably considered in service literature. The service performance scale was developed as a substitute for the SERVQUAL. Many scholars have examined and empirically analyzed the significant influences of these concepts on consumer satisfaction and loyalty. Examining potential moderating and mediating variables on the direct and indirect effects of service quality and service performance on both employee-level and organization-level outputs could improve the knowledge domain. Moreover, service companies have still waited for novel approaches that provide unique remedies for coping with the devastating impacts of the recent pandemic. Thus, scientific endeavors could more focus on redefining the service quality concept and its measurements in the postpandemic world. One possible direction could be proposing a redesigned service encounter where the employee–customer interaction has been revised.

Another investigated cluster relates to service-dominant logic. Service scholars have centered on customer-focused service design. This domain includes vital articles, which theoretically developed an evolving framework from a good-centric approach to a customer-centric approach. Customer cocreation value seems to be the most influential of the service-dominant logic. Customer participation and customer engagement are inherently the main focuses of articles appearing within this cluster. Font et al.’s (2021) study has recently discussed how shared value can contribute to sustainable supply chain management. Another recent study has examined innovation and cocreation value for peer-to-peer accommodation services (Casais et al., 2020). Thus, sustainability and innovation could be more emphasized by future attempts to examine their roles in customer cocreation value. This cluster also shows technology as an important factor triggering the evolution of service research in the millennium. Support of this claim, a very recent study proposes changing the marketing channels of hospitality services (Altinay and Arici, 2021). The authors proposed that “service organizations can keep up with developments in cutting-edge technologies, and those technologies can inaugurate a new era in service by replacing human labor in the service encounter” (p. 26). Thus, future research could investigate the role of cutting-edge technologies in customer service. The interrelationship of technology and customer cocreation value could also be investigated. It needs to be clarified whether could the employee-oriented nature of service organizations be replaced by the new technology?

Methodology and market orientation is the third-largest cluster. Many studies from this domain adopt quantitative data analysis. SEM is the dominant quantitative approach appearing in this cluster. This finding endorses the previous research (Köseoglu et al., 2021) that found hospitality service research has been dominated by methodology-focused articles, particularly, quantitative research methods (i.e. SEM). This calls for further inquiry on methodology papers in various service industries, such as education and banking. A comparative research that evaluates variances of methodology-focused studies among service industries would pay dividends.

Market orientation-focused studies concentrate on antecedents and outcomes of market orientation as well as management focus on the market orientation that cares about clarifying customer needs and wants and generating services that satisfy them. Whilst the subdomain consists of wide-ranging themes, no particular aspect of market orientation has received constant attention. Low et al.’s (2007) study determining how market orientation or its related practices interact with the innovation process could be useful to other aspects of market orientation and it could be time to perform qualitative studies on this intrarelationship. Could the predominance of quantitative analysis (i.e. SEM) be replaced by other methodologies, such as mixed-method including both quantitative and qualitative or bibliometric analysis? Or could the panel data approach provide a more comprehensive insight into service research? These are vital inquiries still waiting for academic attention from the service researchers. Furthermore, market orientation is broadly considered from the organization and managers’ perspective, so investigating the link of the market orientation-innovation process is needed at the employee level to examine whether employees are the linking determinant between the concepts of market orientation and innovation.

The last cluster consists of the service encounter. The conceptual foundations of this cluster consist of such themes as service failure/recovery, employee reactions, customer complaints and customer changing behaviors. This domain broadly discusses the employee–customer interaction in the service encounter. However, technology may be adapted as a new way to solve customer complaints and minimize potential service failures deriving from human errors. Thus, a growing academic interest is needed in the adaptation of technology into the service encounter to help industry practitioners in coping with the service failures and consequently customer complaints.

Considering these five main clusters, we provide research questions that can encourage service researchers to conduct further research in the knowledge domain. We also present related theories for each question that can help scholars conceptually underpin their arguments (see Table 2).

Beyond these five themes, we also acknowledged that we do not have sufficient knowledge of emergent topics in the service research. As mentioned above, recent efforts (Altinay and Arici, 2021; Casais et al., 2020; Font et al., 2021) addressed the adaptation of such emergent concepts including technology, innovation and sustainability and called for more research on expanding our knowledge of these topics and their adaptation in service environments. Considering these recent calls, we invite future researchers to analyze three main themes (i.e. innovation, sustainability and technology) to further expand our knowledge of new trends and implications in service industries in the new era.

Like its predecessors, this study inherently has some limitations that need to be addressed. First, it is well known that a predominance of self-citations can result in biased citation measures. Yet, this study has covered numerous documents published over a large period. Covering such big data is not easy for any researcher to analyze and interpret the citations at a significant level. Second, this study only considers five highly prestigious journals from the service literature. Service-associated articles published out of these journals have not been involved in the study sample. Future studies could expand the sample and apply temporal threshold values to analyze and visualize the progress of the knowledge domain, which can lead to examining the probability that the weights of several most cited articles could decrease in due course, while others appear.

Figures

Figure 1.

Network visualization of service research

Table 1.

Studies of intellectual connection in the service research

Methodological aspects	Main findings
Pilkington and Chai (2008)
435 documents from International Journal of Service Industry Management were analyzed by using network and factor analysis	Citation analysis revealed the strong effect of marketing and consumer research on service as a study discipline. The network diagram suggests that the core literature centers on service quality and customer satisfaction
Gebauer and Reynoso (2013)
16 journals from Scopus database were reviewed and analyzed	Three main study domains are identified in service management: base of the pyramid innovation; international strategies in emerging markets; and corporate social responsibilities and poverty alleviation.
Muñoz-Leiva et al. (2013)
A total of 84 journal articles, books, monographs, reports, theses and conference papers from Web of Science were analyzed via thematic network analysis	The findings showed that the research themes innovation and information have the highest impact
da Silva et al. (2017)
860 journals, books, monographs, reports, theses and conference papers from Web of Science were analyzed via network analysis	Five clusters (service-dominant logic, value cocreation, innovation, customer satisfaction, quality) were revealed
Mendes et al. (2017)
106 journals from Web of Science and Scopus were analyzed by descriptive and network analysis	Four themes were revealed: new service development critical factors, different perspectives of service innovation, new service development literature reviews and new service development process
Donthu et al. (2020)
587 articles from the Journal of Service Research were analyzed descriptive and co-word analysis	The main topics of this journal are big data, value cocreation, customer resource integration, service design and customer participation
Donthu et al. (2021a, 2021b)
1,306 papers published in the Journal of Services Marketing were analyzed by performing keywords co-occurrence and bibliographic coupling analysis	Results group JSM papers into four clusters: brand and customer engagement behavior, service cocreation, service encounters and service recovery and social networking
Donthu et al. (2021a, 2021b)
1,284 papers from the Journal of Service Theory and Practice were analyzed via descriptive and thematic analysis	Five clusters: “service quality and customer satisfaction,” “customer value, customer perception, value cocreation, service excellence,” “customer satisfaction and performance management,” “technology, digitization and operations” and “customer behavior and experience” were revealed
Subramony et al. (2021)
630 papers from the management, psychology, health and service journals were analyzed by conducting bibliometric mapping analysis	Five clusters were found: collective predictors and effects, services encounters, emotional regulation and management, customer orientation and service stress and strain

Table 2.

Future research agenda in services

Questions	Theories
Customer satisfaction and customer relationship
How to enrich service research beyond the positivistic approach?	Theory of innovation Service productivity theory Value cocreation Social comparison theory
How and under which conditions can technology be adopted as an antecedent of customer satisfaction?	Unified theory of acceptance Affinity theory
How and why does customer satisfaction evolve in the postpandemic world?	Customer experience theory Social cognitive theory Chaos theory
What are the changing needs and expectations of customers?	Experience theory Social cognitive theory Transformative learning theory
How to adapt sustainability in customer relations?	Sustainable development Stakeholder theory Social exchange theory
How to transform service companies’ CRM strategies?	Effectuation theory Transformative learning theory Chaos theory Complexity theory
Service quality and servicescape
What are the changing factors affecting service quality perception of customers?	Service quality Transformative learning theory Cognitive consistency theory
Can SERVQUAL still provide valid and reliable results in a service context?	Service quality Control theory Effectuation theory
What are the mediating and moderating variables in the relationship between service quality and employee-level outcomes?	Service quality Social exchange theory Value chain
How to redefine, redesign and redevelop the service quality concept and its measurements in the postpandemic world?	Service marketing triangle Chaos theory Complexity theory Technology acceptance theory Effectuation theory
Service dominant logic: value creation
How can customer cocreation value be proceeded in the new normal?	Service dominant logic Transformative learning theory Customer coproduction Norm activation model Stimulus–organism–response theory
How can sustainability be adopted into the cocreation value?	Sustainability theory Stakeholder theory Corporate social responsibility Stimulus–organism–response theory Value cocreation Social cognitive theory
How to use innovation in ensuring customer cocreation value?	Value cocreation Social innovation theory Resource‐based view Stakeholder theory
What is the changing role of new-generation technologies in achieving cocreation value?	Innovative entrepreneurship Mangle theory Uses and gratifications theory Consumer culture theory
Could employee-oriented nature of service sector be replaced by the new technology? How?	Transformative learning theory Effectuation theory Chaos theory Complexity theory
Can service robots be used more in the future of service context?	Theory of the uncanny valley Institutional theory Stakeholder theory Role theory
Methodology and market orientation
Could predominance of quantitative analysis be replaced by other methodologies?	Technology acceptance
Do field studies provide a better explanation of the service domain?	–
Does longitudinal study present better justification of service domain?	–
How to link market orientation-innovation process?	Theory of organizational learning Resource-advantage theory
Service encounter
Can technology be an antidote to solve customer complaints?	Technology acceptance Customer satisfaction Service fairness theory Appraisal theory
Can technology minimize service failures deriving from human errors?	Technology-based service Theory of the uncanny valley Appraisal theory
Can technology make service context more safe in the postpandemic world?	Theory of planned behavior Stimulus–organism–response theory The unified theory of acceptance and use of technology
How could employee awareness be improved about sustainability in the service context?	Innovation theory Theory of organizational learning The ambidexterity theory of leadership for innovation
How to ensure sustainability in the service industries?	Institutional theory Signaling theory Agency theory
How do service employees react to the pandemic and its effects?	Social exchange theory Social cognitive theory Emotion regulation theory
How can service encounter be designed in the postpandemic world?	Role theory Service encounter needs theory Chaos theory Complexity theory

Appendix

The most cited 100 articles in the service research:

www.researchgate.net/publication/360024163_Appendix_A-Online_supplement

Note: You may find the Appendix in the link. If you face any issue, please contact authors.