The reviewed articles were published in the Journal of Medical Internet Research and 10 of its sister journals. Table 1 provides an overview of the number of articles published in each journal. In total, 38.8% (80/206) of studies applied quantitative methods, with the most common individual method being intervention trials (67/206, 32.5%). Another 18.9% (39/206) of studies applied qualitative methods, whereas 30% (62/206) of studies were conceptual in nature. The remaining 12.1% (25/206) of studies used mixed methods. Regarding the health care context [19], a majority of studies (99/206, 48.1%) focused on individual lifestyle habits. The most prominent theme in this context is achieving an increase in the physical activity of users, as examined by 7.3% (15/206) of studies [10,43,44]. Chronic disease management and rehabilitation is covered by 38.3% (79/206) of studies, including studies on dementia [45,46], diabetes [47,48], or depression [49,50]. Furthermore, 23.3% (48/206) of studies focused on supporting health professionals and mostly dealt with education on various topics, such as emergency care [51], specific surgical procedures [52,53], or teaching ethics in medicine [54].

The 206 studies we reviewed were dated from 2010 to 2020. Across these 206 studies, 137 (66.5%) feature terms related to gamification (gamification, gamified, gamifying, or gamify), whereas 128 (62.1%) feature terms related to serious games (serious AND games, serious AND gaming, or serious AND game) in their full text. There is an overlap of 28.6% (59/206) studies that mention terms related to both concepts. Figure 1 shows the distribution of articles that mention terms related to each concept over time. As can be seen in Figure 1, both concepts became increasingly featured in JMIR journals since 2010, with no concept having a clear edge over the other. Out of the 137 studies that feature gamification, 61 (44.5%) explicitly define the term, contrasted by 76 (55.5%) studies that do not. As for serious games, of the 128 studies, 60 (46.9%) that feature the term provide an explicit definition, whereas 68 (53.1%) do not.

Of the 61 studies that define gamification, a share of 52 (85%) studies explicitly base their definitions on extant literature, whereas 9 (15%) studies provide a self-developed definition. In contrast, out of the 60 studies that define serious games, 50 (83%) explicitly refer to extant literature to do so, whereas 10 (17%) studies do not. In defining gamification, our reviewed papers draw on 29 different sources, whereas for serious games, we found 27 different sources of definitions. Figures 2 and 3 illustrate the different sources our review papers draw on to define gamification or serious games, respectively. Each node represents one such source. The number of times a source has been cited by our review papers is indicated by both the color and size of the corresponding node. An arrow from one node to another indicates that a study draws on another, specifically when defining gamification or serious games.

The most commonly cited source for a gamification definition, cited by 14.1% (29/206) of our reviewed papers, is the seminal paper by Deterding et al [245], who define gamification as “the use of game design elements in nongame contexts.” Considering indirect citations (as indicated by arrows in Figure 2), the percentage value increases to 27.2% (56/206), thus forming the vast majority. Another definition by Deterding et al [246] was used by 2.4% (5/206) of the reviewed papers. Huotari and Hamari [247], Cugelman [1], King et al [248], and Deterding et al [249] are each cited by three (3/206, 1.5%) of the reviewed papers, whereas Zichermann and Cunningham [250], Lister et al [55], Miller et al [251], Lumsden et al [56], Stieglitz et al [252], and Hoffmann et al [57] are each referenced twice (2/206, 1%).

In contrast to gamification, the sources of serious games definitions in our reviewed literature seem to be more fractured and heterogeneous. The most cited paper is that by Michael and Chen [14], cited by 3.4% (7/206) of our reviewed papers. They define serious games as “games that do not have entertainment, enjoyment, or fun as their primary purpose.” In addition to the seven direct citations, Michael and Chen [14] are also cited indirectly 6.3% (13/206) of the time in the definitions of our review papers of serious games (as indicated by arrows in Figure 3). Other prominent sources (based on citation count) include studies by Susi et al [24] (5/206, 2.4%) and Abt [253] (4/206, 1.9%), as well as Deterding et al [245], Zyda [254], Alvarez and Djaouti [255], Bergeron [256], and Marsh [257] (3/206, 1.5%). The remaining sources were cited only once (1/206, 0.5%) or twice (2/206, 1%).

We found that the content of the definitions provided for gamification in the reviewed papers represent several different conceptions. Of the 61 papers defining gamification, 58 (95%) contained only a single definition of the term. Among these articles, 74% (43/58) shared the basic notion of Deterding et al [245,246,249]. They define gamification as either “the use of game design elements in non-game contexts” [245,249] or as an “umbrella term for the use of video game elements (rather than full-fledged games) to improve user experience and user engagement in nongame services and applications” [246]. Both definitions conceptualize gamification as the intentional use of game (design) elements in some kind of nongame artifact. The latter definition, however, explicitly includes the purpose of gamification as improving user experience and user engagement. Similarly, among the 43 papers conceptualizing gamification in line with the basic notion of Deterding et al [245,249], 33 (77%) did not explicitly specify the purpose of gamification. The other 23% (10/43) of papers all specify a variation of engagement, motivation, or both as the purpose of gamification [58-60]. There are also differences regarding the inspiration that gamification draws from games. Although most of the reviewed papers adopt the term game (design) elements from the definition by Deterding et al [245,249], others instead name game (design) techniques [61-64], game principles [65], playful elements [66], game components [67], or game design features [68]. Similarly, the views differed in the artifacts that gamification is applicable to. Instead of nongame contexts, some authors speak of nongame settings [43,69], nongame environments [59], or nongame mechanisms [70]. Others more generally refer to “real world processes or problems” [71], “nongameful or nongamelike situations, services, or tools” [62], or “applications that were not games to begin with” [72].

Another 15 articles provided a single definition that differs from the notion of Deterding et al [245] in a more substantial way. A group of 40% (6/15) of papers specify the nongame context of gamification as either health care [40,73-76] or education [18]. For example, Mendiola et al [75] described gamification as a “feature that offers points, badges, or movement through levels as a health objective is achieved or the more a patient is engaged.” Park and Kim [18] state that “gamification in education applies game elements to an educational context.” Furthermore, 47% (7/15) of articles neither narrowed the context down in a general way nor mentioned a specific context [63,77,78]. For instance, Brown et al [77] refer to gamification as “the application of game design elements to engage and motivate users.” The remaining 13% (2/15) of papers describe gamification as a process to create serious games [79] or focus on gamification as the “overall proliferation of games in culture, society, and technology” [80]. Finally, three papers provide more than one definition of gamification. Among these 3 papers, 2 (67%) [81,82] contrast the aforementioned definition by Deterding et al [245] with an alternative definition that describes gamification as “a process of enhancing a service with affordances for gameful experiences in order to support user’s overall value creation” [247]. Cheng et al [81] argue that the latter definition is more useful in an mHealth context, as it focuses on the goal of gamification instead of its method. Zakaria et al [54] provided various conceptualizations of gamification throughout the article without contrasting them.

Regarding the content of serious games definitions, we first identified different views on how much serious games draw from games. Most studies simply state that serious games “are games” [83,84], whereas some expand on this by limiting serious games to, for example, “full-blown digital games” [85]. Brown et al [86] used this full game characteristic as the sole basis for their self-developed definition, as they define serious games as “the use of games in their entirety (as opposed to selected elements or individual features of a game).” On the contrary, some authors conceptualize serious games not necessarily as full games but rather as “game-like experiences” [87], “the use of game design elements” [58], or as something that “[uses] specific design principles derived from video games” [88]. Some authors even necessitate the presence of specific game elements in a serious game, such as a challenge [89,90], a responsive narrative [91,92], or interactive elements [93]. Four studies also mention that serious games must be situated in a nongame context [58,86,89,94].

Furthermore, we found that 90% (55/61) of papers that provided a definition of serious games relate to the purpose of a serious game. They do so in any of the following 3 ways. First, 15% (8/55) of studies neutrally state that a serious game needs to have any kind of purpose, also described as a characterizing goal [95]. Second, 40% (22/55) of studies state that a serious game needs to have a specific purpose. For example, Mack et al [96] refer to serious games as “games designed to fulfill a serious purpose by providing education from health professionals via a digital device.” Other mentioned purposes include imparting in a user the skills, knowledge, or attitudes that are applicable in the real world [89], or to improve motivation when completing or addressing complex or bothersome tasks [88]. Third, the remaining 45% (25/55) of studies explicitly exclude specific purposes from being the main purpose of a serious game. This nearly unanimously involved excluding entertainment [87,97] or enjoyment [98] as the main purpose of a serious game. Only Gamito et al [99] pass over entertainment and instead state that “serious games are games designed for other purposes than gaming.”

There were also different views in the reviewed literature on the role of entertainment in serious games. As stated earlier, most studies exclude entertainment as the main purpose of a serious game [87,97]. Nevertheless, some authors still consolidate entertainment as a core part of a serious game by explicitly mentioning that serious games “use entertainment” [100] or “[bring] fun spring from video games” [101] or by referring to serious games as “entertaining games” [102,103]. In contrast, Vilardaga et al [97] refer to serious games as “games not for entertainment,” possibly excluding entertainment as part of a serious game altogether. Furthermore, some authors [95,104,105] seem to consider serious games as an augmented form of (entertainment) games in the sense that they do “not simply [provide] entertainment” [87] or “merely entertain” [106] but rather are a “combination of serious aspects with fun” [101] or “intended to be both entertaining and educational” [103]. The studies by Andrade Ferreira et al [45] and Bindoff et al [107] most vividly represent this view, as they start with entertainment games as a basis, and then outline the differences between serious games and entertainment games (eg, an explicit purpose).

Finally, we identified several aspects that were unique to only one or two definitions. DeSmet et al [103] posit that serious games are “a form of organized play.” Similarly, according to Shiyko et al [94], serious games use playful design strategies. The authors also stated that the term serious games is a synonym for a variety of terms, including gamification [58], applied games [108], games with a purpose [107], and transformational games [45]. In 2 studies, Tuti et al [51,109] posited that serious games have to be playable with a mobile phone. Robert et al [100] remarked that a serious game is a contest played against a computer and thus involves only 1 player.

Overall, we identified 59 articles that mention both the terms gamification and serious games in their full texts. We examined these articles to determine the relationship between the 2 terms used by the authors in each case. To start, 14% (8/59) of articles did not allow for an interpretation of the semantic link between the 2 terms (eg, the terms were used without reference to each other in completely different sections of the article). Within the remaining 86% (51/59) of articles, we identified four groups of articles with distinct approaches: (1) implicit distinction, (2) synonymous use of terms, (3) serious games as a type of gamified system, and (4) distinction based on the full game dimension. The 4 approaches are outlined in detail in the following sections.

The first group contained 29% (15/51) of articles that only implicitly differentiated between the terms gamification and serious games. The authors of these articles use the 2 terms in relation to each other in such a way that it becomes clear that they differentiate between the two terms without providing any explanations for why and how to do so. Typical examples of this approach include articles that use and differentiate the terms in enumeration. For example, Park and Kim [18] state “[b]efore gamification, educational games, game-based learning, and serious games were applied to the classroom. As gamification was defined, however, it has become preferred among instructors compared with the other techniques.” Similarly, Martin et al [74] write “[I]n all, 2 different persuasive mechanisms—gamification and serious gaming—were proposed.”

The second group contained 10% (5/51) of articles that used the terms gamification and serious games interchangeably. For example, Booth et al [58] state that “[s]erious gaming or gamification has been defined [...] as ‘the use of game design elements in nongame contexts’ for the purposes of engaging learners in solving complex problems.” Although some authors use the terms synonymously without making it a subject of discussion, others show awareness of conceptual ambiguity. For example, Lumsden et al [56] report: “[There is a] lack of coherence in the field [...] partly due to poor definition of terms; for example, the gamelike tasks covered in this review could be described as ‘serious games,’ ‘gamelike’, ‘gamified’, ‘games with a purpose’, ‘gamed-up’, or simply ‘computer based’.”

The third group contains 43% (22/51) of papers that regard serious games as a type of gamified system. Many authors refer to gamification as the process of developing a game-based intervention. For example, Zhang et al [68] stated that “the gamification approaches used included the addition of gaming elements to existing tasks, transformation of a conventional task into a serious game.” Furthermore, while some of these articles focus on serious games as the only possible outcome of gamification, many other authors seem to share the view that other types of game-based interventions can also be the outcome of gamification. For example, Fornasini et al [44] reported that “a recent trend has revealed virtual physical training through exergames and serious games, making gamification an effective tool to motivate.” In this regard, serious games are also sometimes referred to as systems that integrate “gamification principles and gamification strategies” [110]. However, it mostly remains unclear what is meant by these terms and how they differ from other established terms such as game mechanics, game dynamics, and game aesthetics [258].

The last group contains 18% (9/51) of articles that distinguish between gamification and serious games based on whether the system in consideration is regarded as a full game. For example, de Vette et al [111] state that “gamification is defined as the use of elements from games in nongame contexts to improve user experience and engagement without making that system a full game as is the case with serious games.” However, it largely remains unclear what the criteria are that determine whether a system is a full-fledged game or only gamified. Some authors try to counteract this by giving examples of gamification and serious games that are as vivid as possible. For example, Vermeir et al [60] state that “an interactive world in which players complete challenges designed to improve physical activity” is a typical example for a serious game, whereas a gamified system could be “a mobile health application that uses points and badges to encourage physical activity.” Nevertheless, these authors also report that, in practice, the actual distinction between the 2 concepts can be blurry and highly subjective because of a lack of clear criteria [60].

Through our review, we found that not only are the concepts of gamification and serious games construed in various ways but also their relationship is often fuzzy and unclear. To reduce this conceptual ambiguity, we compiled reporting guidelines consisting of 25 items that are considered essential when reporting studies that deal with game-based interventions and grouped them into 4 topics. In the following sections, we present these items, each accompanied by a description and, where applicable, exemplary statements. A consolidated version that can be used as a quick reference can be found in Multimedia Appendix 2 [245]. A more detailed version including detailed rationales for each individual item may be found in Multimedia Appendix 3 [245].

Game-Based Intervention Reporting Guidelines (GAMING) should be interpreted with some consideration. GAMING are intended to support the reporting of studies on game-based interventions. Although some of the items in GAMING may be beneficial to consider when developing a game-based intervention, our guidelines are not intended to guide the development of game-based interventions per se. GAMING are also intended only for studies that deal with game-based interventions. Accordingly, when we use the term concept in our guidelines, we refer to a type of game-based intervention (eg, gamification, serious games, or exergames). We further differentiated between those concepts that are the thematic focus of the study (henceforth termed core concepts) and those that only have auxiliary roles (henceforth termed related concepts). An example to clarify this: a study may focus on the development of a physical activity intervention based on the paradigm of serious games (core concept) but still compare its results to gamified physical activity interventions or exergames (related concepts). In the following sections, we briefly introduce the contents of our guidelines and the rationales for including them.

The first topic contains items that ensure that the conceptual focus of a study is clear to the authors and readers alike (Table 2).

Ultimately, it should be transparent for the reader, what kind of game-based interventions a study focuses on. A precondition for this is that the authors themselves understand what concepts best reflect the design of the game-based interventions they want to focus on (item 1a). In light of the plethora of existing concepts, as well as the different operationalizations of each, this is by no means a trivial task. Authors may find it beneficial to draw upon concept distinctions from extant literature to establish their conceptual focus. To decide between gamification and serious games, we compiled several distinctions from extant literature that authors may use as decision support (Multimedia Appendix 4). After deciding on their core concepts, the authors should communicate this decision early in their manuscript and include information on how the decision was reached (1b). This allows the reader to comprehend their decisions and grasp the study’s conceptual focus. Furthermore, we suggest that authors should be mindful of the metadata they supply their study with (1c). When reviewing the extant literature, researchers often use metadata to initially assess the conceptual focus of a study and subsequently derive its relevance for their own purposes. Although we acknowledge that broadly diversified metadata increases the visibility of a study, it can also blur the conceptual focus of a study and increase noise for meta-studies or literature reviews.

The items that we propose for the second topic (Table 3) are intended to clarify the knowledge contribution of a study to both authors and readers.

We believe that there are various research streams proximal to different concepts. What constitutes a research stream can be interpreted in various ways. Broadly, we understand a research stream as a set of studies with similar properties, such as their health care context (eg, all studies that describe the design of gamified physical activity interventions), or their applied methodology (eg, all studies that conduct literature reviews on serious games).

Each research stream comes with its own thematic emphasis and viewing angle. Thus, the transferability of knowledge between different research streams requires care and consciousness. For instance, insights from studies focusing on physical activity are often not transferable to studies focusing on health professionals’ education [19]. Similarly, knowledge about badges is not necessarily transferable to leaderboards, although both approaches may be labeled as gamification. Thus, we think that authors should consciously decide which research streams they contribute to (2a). To facilitate transparency, the authors should communicate their decision to their readers (2b). By also including insights into the decision process (eg, explaining the criteria that shaped the decision for a research stream) in their manuscript, readers can gain a better understanding of a study’s setting and on the generalizability and transferability of its results. After deciding on a research stream, the authors should clarify their study’s contribution to the knowledge base of the research stream, including the boundaries of their study (2c). By doing so, readers can understand how the study contributes to a better understanding of core concepts. Furthermore, the ultimate goal of any intervention is usually to solve a problem in practice (eg, sedentary lifestyles). Accordingly, to foster an understanding of how specific game-based interventions can help to solve these problems, we recommend that the authors clarify their study’s practical contribution (2d). Finally, for an understanding of game-based interventions, it is vital that the outcomes of an intervention are reported and attributed to the chosen type of game-based intervention in an as granular way as possible (2e). In this way, readers can easily contextualize knowledge and understand whether an outcome is, for example, evoked by a specific game element (eg, leaderboards) or connected to a specific affective outcome (eg, envy). We also encourage authors to embrace negative outcomes of their game-based interventions, as these, despite them usually not being the desired outcome of an intervention, can notably contribute to a better understanding of a concept [262].

Items in the third topic (Table 4) are concerned with ensuring that authors are mindful of the conceptual ambiguities surrounding game-based interventions and possible consequences for their study.

First, we think that studies benefit if authors identify related concepts that are in close proximity to the core concepts (3.1a). Considering any pair of concepts, the boundaries between these closely related concepts will likely be the vaguest, which also makes them the most important boundaries to define to avoid conceptual ambiguities. Authors may assess the “proximity” of 2 concepts based on various contextual factors of an intervention, such as targeted health behavior. For example, in a physical activity context, exergames are a prominent related concept to consider. Similarly, terms with high linguistic proximity are likely to be candidates for related concepts. As Tan et al [72] remarked in their study, the terms serious games and serious gaming, although ostensibly the same, can be construed as 2 different concepts that describe different classes of game-based interventions (ie, serious games describe games specifically designed for the serious purpose of health education, whereas serious gaming is the use of any game for said purpose). For each related concept, the authors should also consider the benefits of introducing it in their manuscript. Increasing the number of concepts introduced by nature also increases the possibility of conceptual ambiguity. In our review, we faced anecdotal mentions of gamification or serious games, which were often difficult to interpret regarding the authors’ understanding of the individual concepts and the relationship between the two. Thus, we argue that concepts should only be introduced when they are substantive for understanding a study (3.1b). This also leads to less noise for meta-studies as well as less confusion for readers, as they have to keep track of only substantive concepts. Our guidelines also account for mindfulness regarding conceptual ambiguities in the vocabulary surrounding game-based interventions (3.1c). In game-based interventions, many terms can be quite nuanced or not necessarily correspond to its intuitive meaning. For instance, in games research, the term game aesthetics not only describes the artistic value of a game’s visual interface but may also refer to the desirable emotional responses evoked in the player [258]. Accordingly, we suggest being precise while using vocabulary in the domain of any concept and not lightheartedly use or arbitrarily adapt possibly nuanced terms. As there are at least theoretical differences between most concepts, we also highly discourage the interchangeable use of concepts in a manuscript (3.1d). If several concepts are summarized under an umbrella term, this should be done in a transparent way to avoid confusing the reader.

Furthermore, we think that authors should be mindful of the applicability of insights from extant literature to their own research in 2 ways. First, if a researcher finds a study that is labeled as focusing on the same concept that they are trying to investigate, it does not necessarily follow that the researcher and the authors of said study have the same understanding of the concept in question. As our literature review illustrates for gamification and serious games, there are various understandings that are not always reconcilable. Hence, it is advisable to be mindful about conceptual ambiguities when reviewing the extant literature on game-based interventions (3.2a) and ideally challenging the label of each study against one’s own understanding. Second, when transferring knowledge from one concept to another, the authors should carefully consider the possible theoretical and empirical differences in the respective concepts. This aspect is supported by extant research that found several empirical differences with regard to the psychological and behavioral outcomes of gamification and serious games [26]. Such differences can easily impede the transferability of knowledge from one concept to another. Thus, the authors should not presume the easy transferability of knowledge from one concept to another (3.2b). Furthermore, after assessing transferability, authors should precisely specify what knowledge they draw from extant literature and why they think that said knowledge is transferable to their study (3.2c). This empowers the reader to put statements into the context of extant literature and allows a better understanding of how knowledge may be transferable, despite possible conceptual differences.

The items in the fourth topic (Table 5) focus on aligning the understandings of authors and the reader regarding the introduced concepts.

They cover individual concept definitions as well as the relationships between concepts. Having chosen that they want to introduce a certain concept, authors should first familiarize themselves with how extant literature defines it (4.1a). They should then decide whether they want to adopt a definition from the extant literature or need a self-developed definition (4.1b). The latter may especially be the case if authors find that there are no definitions for a concept in extant literature, deficits in existing definitions, or if they feel that their view of a concept is not sufficiently covered by any existing definition. Challenging existing definitions can bring vast benefits to the theoretical development of a research stream. In most cases, however, authors are better off when they build on existing definitions, as this may allow better placement within extant research and facilitate the building of cumulative knowledge. In particular, we urge not to reinvent the wheel when providing any self-developed definition. For most game-based intervention concepts, multiple prominent definitions exist that together cover a large range of views (eg, the studies by Deterding et al [245] or Huotari and Hamari [247] for gamification and the studies by Michael and Chen [14] or Alvarez and Djaouti [255] for serious games). Hence, authors should always consider first if they want to align their views with those of the extant literature.

Irrespective of the source of a definition, it is vital that authors explicitly define every concept introduced in their study (4.2a) to ensure that readers and authors share a common understanding. A lack of an explicit definition for a concept requires the reader to subjectively appraise the authors’ understanding of it based on context. Throughout our literature review, we found that about half of the mentions of gamification or serious games are not accompanied by an explicit definition and thus require such an appraisal, which is likely error-prone. Furthermore, concepts should not be initially defined based on their boundaries to other concepts but rather in an independent manner. For example, statements such as “exergames are games that differ from serious games in [...]” do not fully reveal an author’s understanding of exergames to readers, but only that they somehow differ from serious games. Defining concepts should be done in a principal clause to ensure that a definition is actually recognized as such. Ideally, authors should also justify their choice for a particular concept definition, as this can provide valuable context to the reader (eg, the knowledge that a particular definition is the most used in a particular discipline). Once all concepts (ie, core concepts and related concepts that are substantive in the sense of 3.1b) are independently defined, the boundaries between concepts can be established (4.2b). Explicitly drawing the boundaries between concepts is the most reliable way to mitigate conceptual ambiguities. Ideally, the boundaries between all possible pairs of introduced concepts are drawn. In cases where this is infeasible (eg, due to a large number of introduced concepts), the boundaries adjacent to the core concepts of a study take priority. The study by Park and Kim [18] is a good example to note the benefits of properly introducing and delineating related concepts. They focus on developing a gamified learning environment, making gamification their core concept. Owing to their proximity to the education context, they identify the related concepts of game-based learning and educational gaming, define them individually, and subsequently sharpen their contribution by stating that gamification is their preferred intervention design for being a more accessible technique for teachers than the other concepts.

If authors decide to adopt definitions from the extant literature, it is important that they establish a clear and unambiguous connection to their respective sources. To do so, researchers should first aim to identify the original source of a definition (4.3a). Readers with domain knowledge are usually able to recognize prominent sources of definitions (especially in the case of seminal papers) and can then immediately attribute a study to a certain view of a concept. Not citing the original source of a definition (ie, indirect citation) obfuscates the original source of a definition and prevents this process. To ensure that a definition can be attributed to its source, the source should be explicitly referenced immediately after the principal clause that contains the definition (4.3b).

Formulating a good self-developed definition is a nontrivial task that requires great care. Authors that decide to do so find support in guidelines for a good definition design (4.4a). Although there is no universal way to formulate definitions, authors may consider general guidelines on definition design [263] or take guidance from definition development principles in other areas [264]. Within the context of our study, we particularly emphasize avoiding the use of any part of the term that is defined within the definition of the term itself. For example, when defining serious games as games with a serious purpose, the question immediately follows, how games and serious purposes are defined, essentially leaving the reader none the wiser concerning the meaning of serious games. Whenever authors decide on a self-developed definition of a concept (considering 4.1b), they should also allow the reader to comprehend this decision by clarifying from which view their self-developed definition emerged (4.4b). By fostering an understanding of the decision for a self-developed definition, the reader can also better grasp how a study contributes to an advanced, possibly novel understanding of a concept.

Finally, in some cases, authors may find it beneficial to name several definitions of a single concept, for example, to contrast different views [81,265] or to outline the theoretical development of a concept [112]. To avoid confusing the reader, they should clarify which definition they apply in their study (4.5a) and subsequently apply this definition consistently (4.5b). By further rationalizing the reasons for the choice of a specific definition or concept view, authors can increase the comprehension of the reader of why a certain definition was chosen.