Designing conceptual articles: four approaches

As a powerful means of theory building, conceptual articles are increasingly called for in marketing academia. However, researchers struggle to design and write non-empirical articles because of the lack of commonly accepted templates to guide their development. The aim of this paper is to highlight methodological considerations for conceptual papers: it is argued that such papers must be grounded in a clear research design, and that the choice of theories and their role in the analysis must be explicated and justified. The paper discusses four potential templates for conceptual papers – Theory Synthesis, Theory Adaptation, Typology, and Model – and their respective aims, approach for using theories, and contribution potential. Supported by illustrative examples, these templates codify some of the tacit knowledge that underpins the design of non-empirical papers and will be of use to anyone undertaking, supervising, or reviewing conceptual research.


Introduction
The major academic journals in the field of marketing acknowledge the need for good conceptual papers that can "bridge existing theories in interesting ways, link work across disciplines, provide multi-level insights, and broaden the scope of our thinking" (Gilson and Goldberg 2015, p. 128). Indeed, many of the most impactful marketing papers of recent decades are conceptual as this type of research enables theory building unrestricted by the demands of empirical generalization (e.g., Vargo and Lusch 2004). Authors crafting conceptual papers can find valuable advice on problematizing (Alvesson and Sandberg 2011), theorizing and theory building (Corley and Gioia 2011;Cornelissen 2017;Shepherd and Suddaby 2017), and the types of conceptual contribution that warrant publication (Corley and Gioia 2011;MacInnis 2011). However, a lack of commonly accepted templates or "recipes" for building the paper means that writing a conceptual piece can be a struggle (Cornelissen 2017). As a result, reviewers often face conceptual papers that offer little more than a descriptive literature review or interesting but disjointed ideas.
In empirical papers, the recipe typically is the research design that provides the paper structure and logic, guiding the process of developing new knowledge and offering conventions for reporting the key elements of the research (Flick 2018, p. 102). The research design explains how the ingredients of the study were selected, acquired, and analyzed to effectively address the research problem, and reviewers can evaluate the robustness of this process by reference to established conventions in the existing literature. As conceptual papers generally do not fit the mold of empirical research, authors and reviewers lack any such recipe book, making the critical issue of analytical rigor more challenging.
This paper addresses issues of methodology and research design for conceptual papers. The discussion is built on previous "how to" guides to conceptual research, and on examples from high quality journals to identify and illustrate different options for conceptual research design. This paper discusses four templates-Theory Synthesis, Theory Adaptation, Typology, and Model-and explicates their aims, their approach to theory use, and their contribution potential. The paper does not focus on theory building itself but supports it, as analytical rigor is a prerequisite for high quality theorizing. Nor is the focus on literature reviews or meta-analyses; while these are important non-empirical forms of research, there are well articulated existing guidelines for such articles (see for example Webster and Watson 2002;Palmatier et al. 2018).
The ultimate goal of this paper is to direct scholarly attention to the importance of a systematic approach to developing a conceptual paper. Experienced editors and reviewers have noted that researchers sometimes underestimate how difficult it is to write a rigorous conceptual paper and consider this an easy route to publishing-an essay devoid of deeper scholarship (Hirschheim 2008). In reality, developing a cogent argument and building a supporting theoretical explanation requires tacit knowledge and skills that doctoral programs seldom teach (Yadav 2010;King and Lepak 2011). As Fulmer puts it, "in a theoretical paper the author is faced with a mixed blessing: greater freedom and page length within which to develop theory but also more editorial rope with which to hang him/herself" (2012, p. 330).
The paper is organized as follows. The next section outlines key methodological requirements for conceptual studies. Four common types of research design are then identified and discussed with supporting examples. The article ends with conclusions and recommendations for marketing scholars undertaking, supervising, or reviewing conceptual research.

Conceptual papers: some methodological requirements
The term "research design" refers to decisions about how to achieve research goals, linking theories, questions, and goals to appropriate resources and methods (Flick 2018, p. 102). In short, the research design is a plan for collecting and analyzing evidence that helps to answer the question posed (Ragin 1994, p. 191). Like any design, the research design should improve usability; a good research design is the optimal tool for addressing the research problem, and it communicates the logic of the study in a transparent way. In principle, any piece of research should be designed to deliver trustworthy answers to the question posed in a credible and justified manner.
An empirical research design typically involves decisions about the underlying theoretical framing of the study as well as issues of data collection and analysis (e.g. Miller and Salkind 2002). Imagine, for example, an empirical paper where the authors did not argue for their sampling criteria or choice of informants, or failed to define the measures used or to show how the results were derived from the data. It can be argued that conceptual papers entail similar considerations (Table 1), as the omission of equivalent elements would create similar confusion. In other words, a well-designed conceptual paper must explicitly justify and explicate decisions about key elements of the study. The following sections elaborate more specifically on designing and communicating these "methodological" aspects of conceptual papers.
Explicating and justifying the choice of theories and concepts Empirical and conceptual papers ultimately share a common goal: to create new knowledge by building on carefully selected sources of information combined according to a set of norms. In the case of conceptual papers, arguments are not derived from data in the traditional sense but involve the assimilation and combination of evidence in the form of previously developed concepts and theories (Hirschheim 2008). In that sense, conceptual papers are not without empirical insights but rather build on theories and concepts that are developed and tested through empirical research.
In an empirical study, the researcher determines what data are needed to address the research questions and specifies sampling criteria and research instruments accordingly. In similar fashion, a conceptual paper should explain how and why the theories and concepts on which it is grounded were selected. In simple terms, there are two possible points of departure. The first option is to start from a focal phenomenon that is observable but not adequately addressed in the existing research. The authors may inductively identify differing conceptualizations of that phenomenon, and then argue that the aspect of interest is best addressed in terms of particular concepts or theories. That is, the choice of concepts is based on their fit to the focal phenomenon and their complementary value in conceptualizing it. One key issue here is how the researcher conceptualizes the empirical phenomenon; in selecting particular concepts and theories, the researcher is de facto making an argument about the conceptual ingredients of the empirical phenomenon in question.
A second and perhaps more common approach is to start from a focal theory by arguing that a particular concept, theory, or research domain is internally incoherent or incomplete in some important respect and then introducing other theories to bridge the observed gaps. In this case, the choice of theories or concepts is based on their ability to address the observed shortcoming in the existing literature, i.e. their supplementary value. This simplified account raises a critical underlying question: what is the value that each selected concept, literature stream, or theory brings to the study, and why are they selected in preference to something else?
Explicating the role of different theories and concepts in the analysis Conceptual papers typically draw on multiple concepts, literature streams, and theories that play differing roles. It is difficult to imagine a (published) empirical paper where the reader could not distinguish empirical data from the literature review. In a conceptual paper, however, it is sometimes difficult to tell which theories provide the "data" and which are framing the analysis. In this regard, Lukka and Vinnari (2014) drew a useful distinction between domain theory and method theory. A domain theory is "a particular set of knowledge on a substantive topic area situated in a field or domain" (ibid, p. 1309)-that is, an area of study characterized by a particular set of constructs, theories, and assumptions (MacInnis 2011). A method theory, on the other hand, is "a meta-level conceptual system for studying the substantive issue(s) of the domain theory at hand" (Lukka andVinnari 2014, p. 1309). For example, Brodie et al. (2019) sought to advance engagement research (domain theory) by drawing new perspectives from service-dominant logic (method theory). The distinction is relative rather than absolute; whether a particular theory is domain or method theory depends on its role in the study in question (Lukka and Vinnari 2014). Indeed, a single study can accommodate multiple domain and method theories.
In a conceptual paper, one crucial function of the research design is to explicate the role of each element in the paper; failure to explain this is likely to render the logic of "generating findings" practically invisible to the reader. Defining the roles of different theories also helps to indicate the paper's positioning, and how its contribution should be evaluated. Typically, the role of the method theory is to provide some new insight into the domain theory-for example, to expand, organize, or offer a new or alternative explanation of concepts and relationships. This means that contribution usually centers on the domain theory, not the method theory (Lukka and Vinnari 2014). For example, marketing scholars often use established theories such as resource-based theory, institutional theory, or practice theory as method theories, but any suitable framework (even from other disciplines) can play this role. 1

Making the chain of evidence visible and easy to grasp
Conceptual papers typically focus on proposing new relationships among constructs; the purpose is thus to develop logical and complete arguments about these associations rather than testing them empirically (Gilson and Goldberg 2015). The issue of how to develop logical arguments is hence pivotal. As well as arguing that concepts are linked, authors must provide a theoretical explanation for that link. As that explanation demonstrates the logic of connections between concepts, it is critical for theory building (King and Lepak 2011).
In attempting to analyze what constitutes a good argument, Hirschheim (2008) adopted a framework first advanced by the British philosopher Toulmin (1958), according to which an argument has three necessary components: claims, grounds, and warrants. Claims refer to the explicit statement or thesis that the reader is being asked to accept as true-the outcome of the research. Grounds are the evidence and reasoning used to support the claim and to persuade the reader. In a conceptual paper, this evidence is drawn from previous studies rather than from primary data. Finally, warrants are the underlying assumptions or presuppositions that link grounds to claims. Warrants are often beliefs implicitly accepted within the given research domain-for example the assumption that organizations strive to satisfy their customers. In a robust piece of research, claims should be substantiated by sufficient grounds, and should be of sufficient significance to make a worthwhile contribution to knowledge (Hirschheim 2008).
In practice, the chain of evidence in a conceptual paper is made visible to the reader by explicating the key steps in the argument. How is the studied phenomenon conceptualized? What are the study's implicit assumptions, stemming from its theoretical underpinnings? Are the premises and axioms used to ground the arguments sufficiently explicit to enable another researcher to arrive at similar analytical conclusions? Conceptual clarity, parsimony, simplicity, and logical coherence are important qualities of any academic study but are arguably all the more critical when developing arguments without empirical data.
A paper's structure is a strong determinant of how easy it is to follow the chain of argumentation. While there is no single best way to structure a conceptual paper, what successful papers have in common is a careful matching of form and structure to theoretical purpose of the paper (Fulmer 2012). The structure should therefore reflect both the aims of the research and the role of the various lenses deployed to achieve those aims-in other words, the structure highlights what the Choice of theories and concepts analyzed Unit of analysis Perspective; level(s) of analysis /aggregation Variables studied (independent/dependent) Key concepts to be analyzed/explained or used to analyze/explain Operationalization, scales, measures Translation of target phenomenon in conceptual language; definitions of key concepts Approach to data analysis Approach to integrating concepts; quality of argumentation authors seek to explain. A clear structure also contributes to conceptual clarity by making the hierarchy of concepts and their elements intuitively available to the reader, eliminating any noise that might distort the underlying message. As Hirschheim (2008) noted, a clear structure ensures a place for everything-omitting nothing of importance-and puts everything in its place, avoiding redundancies.

Common types of research design in conceptual papers
In marked contrast to empirical research, there is no widely shared understanding of basic types of research design in respect to conceptual papers, with the exception of literature reviews and meta-analyses. To address this issue, the present study considers four such types: Theory Synthesis, Theory Adaptation, Typology, and Model (see Table 2). These types serve to clarify differences of methodological approach-that is, how the argument is structured and developed-rather than the types of conceptual contributions that are the main consideration of MacInnis (2011). The four types discussed here derive from an analysis of goal setting, structuring, and logic of argumentation in multiple articles published in high quality journals. It should be said that the list is not exhaustive, and other researchers would no doubt have formulated differing perspectives. Nevertheless, the presented scheme can inspire researchers to explore and explicate one's approach to conceptual research, and perhaps to formulate an alternative approach. It should also be noted that the goals of a conceptual article can be as varied as in any other form of academic research. Table 2 identifies some possible or likely goals for each suggested type; these are not mutually exclusive and are often combined.

Theory synthesis
A theory synthesis paper seeks to achieve conceptual integration across multiple theories or literature streams. Such papers offer a new or enhanced view of a concept or phenomenon by linking previously unconnected or incompatible pieces in a novel way. Papers of this type contribute by summarizing and integrating extant knowledge of a concept or phenomenon. According to MacInnis (2011), summarizing helps researchers see the forest for the trees by encapsulating, digesting, and reducing what is known to a manageable whole. Integration enables researchers to see a concept or phenomenon in a new way by transforming previous findings and theory into a novel higher-order perspective that links phenomena previously considered distinct (MacInnis 2011). For example, a synthesis paper might chart a new or unstructured phenomenon that has previously been addressed in piecemeal fashion across diverse domains or disciplines.
Such papers may also explore the conceptual underpinnings of an emerging theory or explain conflicting research findings by providing a more parsimonious explanation that pulls disparate elements into a more coherent whole. This kind of systematization is especially helpful when research on a given topic is fragmented across different literatures, helping to identify and underscore commonalities that build coherence (Cropanzano 2009). For example, in their review of conceptualizations of customer experience across multiple literature fields, Becker and Jaakkola's (2020) analysis of the compatibility of various elements and assumptions provided a new integrative view that could be generalized across settings and contexts. In more mature fields, synthesis can help to identify gaps in the extant research, which is often the goal of systematic literature reviews. However, gap spotting is seldom a sufficient source of contribution as the main aim of a conceptual paper should be to enhance existing theoretical understanding on the studied phenomenon or concept. The synthesis paper represents a form of theorizing that emphasizes narrative reasoning that seeks to unveil "big picture" patterns and connections rather than specific causal mechanisms (Delbridge and Fiss 2013).
Although there is sometimes a fine line between theory synthesis and literature review, there remains a clear distinction between the two. While a well-crafted literature review takes stock of the field and can provide valuable insights into its development, scope, or future prospects, it remains within the existing conceptual or theoretical boundaries, describing extant knowledge rather than looking beyond it. In the case of a conceptual paper, the literature review is a necessary tool but not the ultimate objective. Moreover, in a theory synthesis paper, the role of the literature review is to unravel the components of a concept or phenomenon and it must sometimes reduce or exclude incommensurable elements. A lack of elegance occurs when authors attempt to hammer together separate research ideas in a series of "minireviews" instead of attending to a single conceptual theme (Cropanzano 2009). For example, a literature review that seeks to integrate multiple research perspectives may instead merely summarize in separate chapters what each has to say about the concept. Typically, different research perspectives employ differing terms and structure, or categorize conceptual elements in distinct ways. Integration and synthesis requires that the researcher explicates and unravels the conceptual underpinnings and building blocks that different perspectives use to conceptualize a phenomenon, and the looks for common g r o u n d o n w h i c h t o b u i l d a n e w a n d e n h a n c e d conceptualization.
A theory synthesis paper may seek to increase understanding of a relatively narrow concept or empirical phenomenon. For example, Lemon and Verhoef (2016) summarized the conceptual background and extant conceptualizations of customer journeys to produce a new integrative view. They Ultimately, a theory synthesis paper can integrate an extensive set of theories and phenomena under a novel theoretical umbrella. One good example is Vargo and Lusch's (2004) seminal article, which pulled together key ingredients from diverse fields such as market orientation, relationship marketing, network management, and value management into a novel integrative narrative to formulate the more parsimonious framework of service-dominant logic. In so doing, they drew on resource based theory, structuration theory, and institutional theory as method theories to organize and synthesize concepts and themes from middle-range literature fields (e.g., Lusch 2004, 2016). While extant research provided the basis for a novel framework, existing concepts were decomposed into such fine-grained ingredients that the resulting integration was a new theoretical view in its own right rather than a summary of existing concepts.

Theory adaptation
Papers that focus on theory adaptation seek to amend an existing theory by using other theories. While empirical research may gradually extend some element of theory within a given context, theory-based adaptation attempts a more immediate shift of perspective. Theory adaptation papers develop contribution by revising extant knowledge-that is, by introducing alternative frames of reference to propose a novel perspective on an extant conceptualization (MacInnis 2011). The point of departure for such papers, then, is the problematization of a particular theory or concept. For example, the authors might argue that certain empirical developments or insights from other streams of literature render an existing conceptualization insufficient or conflicted, and that some reconfiguration or shift of perspective or scope is needed to better align the concept or theory to its purpose or to reconcile certain inconsistencies. Typically, the researcher draws from another theory that is equipped to guide this shift. The contribution of this type of a paper is often positioned to the domain where the focal concept is situated.
The starting point for the theory adaptation paper is the theory or concept of interest (domain theory). Other theories are used as tools, or method theories (Lukka and Vinnari 2014) to provide an alternative frame of reference to adjust or expand its conceptual scope. One "method" of adaptation is to switch the level of analysis; for example, Alexander et al. (2018) provided new insights into the influence of institutions on customer engagement by shifting from a micro level analysis of customer relationships-the prevailing view in the field-to meso and macro level views, adapting Chandler and Vargo's (2011) process of oscillating foci. Another option is to use an established theory to explore new aspects of the domain theory (Yadav 2010). As one example of this type of design, Brodie et al. (2019) argued for the practical and theoretical importance of expanding the scope of engagement research in two ways: from a focus on consumers to a broad range of actors, and from dyadic firm-customer relationships to networks. As well as justifying why a particular extension or change of focus is needed, a theory adaptation paper must also show that the selected method theory is the best available option. For example, Brodie et al. (2019) explained that they employed service-dominant logic to broaden the conceptual scope of engagement research because it offered a lens for understanding actor-to-actor interactions in networks. Similarly, Hillebrand et al. (2015) used multiplicity theory to revise existing perspectives on stakeholder marketing by viewing stakeholder networks as continuous rather than discrete. They argued that this provides a more accurate understanding of markets characterized by complex value exchange and dispersed control.

Typology
A typology paper classifies conceptual variants as distinct types. The aim is to develop a categorization that "explains the fuzzy nature of many subjects by logically and causally combining different constructs into a coherent and explanatory set of types" (Cornelissen 2017). A typology paper provides a more precise and nuanced understanding of a phenomenon or concept, pinpointing and justifying key dimensions that distinguish the variants.
T y p o l o g y p a p e r s c o n t r i b u t e t h r o u g h differentiation-distinguishing, dimensionalizing, or categorizing extant knowledge of the phenomenon, construct, or theory in question (MacInnis 2011). Typologies reduce complexity (Fiss 2011). They demonstrate how variants of an entity differ, and hence organize complex networks of concepts and relationships, and may help by recognizing their differing antecedents, manifestations, or effects (MacInnis 2011). Typologies also offer a multidimensional view of the target phenomenon by categorizing theoretical features or dimensions as distinct profiles that offer coordinates for empirical research (Cornelissen 2017). For example, the classic typologies elaborated by Mills and Margulies (1980) and Lovelock (1983) assigned services to categories reflecting different aspects of the relationship between customers and the service organization, facilitating prediction of organizational behavior and marketing action. These theory-based typologies have informed numerous empirical applications.
The starting point for a typology paper is typically recognition of an important but fragmented research domain characterized by differing manifestations of a concept or inconsistent findings regarding drivers or outcomes. The researcher accumulates knowledge of the focal topic and then organizes it to capture the variability of particular characteristics of the concept or phenomenon. For example, after exploring different approaches to service innovation, Helkkula et al. (2018) proposed a typology of four archetypes. They suggested that variance within the extant research could be explained by differences of theoretical perspective and argued that each type had distinct implications for value creation.
The dimensions of a typology can also be differentiated by applying another theory (i.e. methods theory) that provides a logical explanation of why differences exist and why they are relevant. For example, to examine the boundaries of resource integration, Dong and Sivakumar (2017) developed a typology of customer participation, using dimensions drawn from resource-based theory, to address the fundamental resource deployment questions of whether there is a choice in terms of who performs a task and what task is performed (Kozlenkova et al. 2014). Snow and Ketchen Jr. (2014) argued that well-developed typologies are more than just classification systems; rather, a typology articulates relationships among constructs and facilitates testable predictions (cf. Doty and Glick 1994). In this way, a typology can propose multiple causal relationships in a given setting (Fiss 2011). While a typology paper enhances understanding of a phenomenon by delineating its key variants, it can be seen to differ from a synthesis or adaptation paper by virtue of its explanatory character. This is the typology's raison d'etre; types always explain something, and the dimensions that distinguish types account for the different drivers, outcomes, or contingencies of particular variants of the phenomenon. By accommodating asymmetric causal relations, typologies facilitate the development of configurational arguments beyond simple correlations (Fiss 2011).

Model
The model paper seeks to build a theoretical framework that predicts relationships between concepts. A conceptual model describes an entity and identifies issues that should be considered in its study: it can describe an event, an object, or a process, and explain how it works by disclosing antecedents, outcomes, and contingencies related to the focal construct (Meredith 1993;MacInnis 2011). This typically involves a form of theorizing that seeks to create a nomological network around the focal concept, employing a formal analytical approach to examine and detail the causal linkages and mechanisms at play (Delbridge and Fiss 2013). A model paper identifies previously unexplored connections between constructs, introduces new constructs, or explains why elements of a process lead to a particular outcome (Cornelissen 2017;Fulmer 2012).
The model paper contributes to extant knowledge by delineating an entity: its goal is "to detail, chart, describe, or depict an entity and its relationship to other entities" (MacInnis 2011). In a conceptual article, creative scope is unfettered by data-related limitations, allowing the researcher to explore and model emerging phenomena where few empirical data are available (Yadav 2010). The model paper typically contributes by providing a roadmap for understanding the entity in question by delineating the focal concept, how it changes, the processes by which it operates, or the moderating conditions that may affect it (MacInnis 2011).
A model paper typically begins from a focal phenomenon or construct that warrants further explanation. For example, Huang and Rust (2018) sought to explain the process and mechanism by which artificial intelligence (AI) will replace humans in service jobs. They employed literature that tackles key variables associated with the target phenomenon: service research illuminates the focal phenomenon, technologyenabled services, and research across multiple disciplines discusses the likely impact of AI on human labor. By synthesizing this literature pool, they identified four types of intelligence and then built a theory that could predict the impact of AI on human service labor. This involved a particular kind of formal reasoning, supported by research from multiple disciplines and real-world applications (Huang and Rust 2018). In other words, the authors use method theories and deductive reasoning to explain relationships between key variables, facilitated by theories in use (MacInnis 2011).
Model papers typically summarize arguments in the form of a figure that depicts the salient constructs and their relationships, or as a set of formal propositions that are logical statements derived from the conceptual framework (Meredith 1993). For example, Payne et al. (2017) used resource-based theory to develop a conceptual model of the antecedents and outcomes of customer value propositions. While figures and propositions of this kind help the reader by condensing the paper's main message, Delbridge and Fiss (2013) noted that they are also a double-edged sword. At their best, propositions distill the essence of an argument into a parsimonious and precise form, but by virtue of this very ability, they also put a spotlight on the weaknesses in the argument chain. According to Cornelissen (2017), the researcher should therefore be clear about the "causal agent" in any proposed relationship between constructs when developing propositionsin other words, the trigger or force that drives a particular outcome or effect. Careful consideration and justification of the choice of theories and the manner in which they are integrated to produce the arguments is hence pivotal in sharpening and clarifying the argumentation to convince reviewers and readers.

Conclusions
This paper highlights the role of methodological considerations in conceptual papers by discussing alternative types of research design, in the hope of encouraging researchers to critically assess and develop conceptual papers accordingly. Authors of conceptual papers should readily answer the following questions: What is the logic of creating new knowledge? Why are particular information sources selected, and how are they analyzed? What role does each theory play? For reviewers, assessing conceptual papers can be difficult not least because the generally accepted and readily available guidelines for evaluating empirical research seldom apply directly to non-empirical work. By asking these questions, reviewers and supervisors can evaluate whether the research design of a paper or thesis is carefully crafted and clearly communicated to the reader.
The paper identifies four types of conceptual papers-Theory Synthesis, Theory Adaptation, Typology, and Model-and discusses their aims, methods of theory use, and potential contributions. Although this list is not exhaustive, these types offer basic templates for designing conceptual research and determining its intended contribution (cf. MacInnis 2011). Careful consideration of these alternative types can facilitate more conscious selection of approach and structure for a conceptual paper. Researchers can also consider opportunities for combining types. In many cases, mixing two types can be an attractive option. For example, after distinguishing types of service innovation in terms of their conceptual underpinnings, Helkkula et al. (2018) synthesized a novel conceptualization of service innovation that exploited the strengths of each type and mitigated their limitations. Typologies can also provide the basis for models, and synthesis can lead to theory adaptation. This paper highlights the many alternative routes along which conceptual papers can advance extant knowledge. We should consider conceptual papers not just as a means to take stock, but to break new ground. Empirical research takes time to accumulate, and the scope for generalization is relatively narrow. In contrast, conceptual papers can strive to advance understanding of a concept or phenomenon in big leaps rather than incremental steps. To be taken seriously, any such leap must be grounded in thorough consideration and justification of an appropriate research design.
Funding Information Open access funding provided by University of Turku (UTU) including Turku University Central Hospital.
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