Tourism Knowledge Domains of Chinese and International Research

: Tourism knowledge domain has always been one of the appealing topics in tourism academic circle. This paper extracted author-selected keywords from 4788 articles published from 2012 to 2021 in four authoritative journals: Annals of Tourism Research , Tourism Management , Journal of Sustainable Tourism and Tourism Tribune. These keywords were coded according to “research areas”, “research objects”, “research methods”, and “research disciplines”, and a statistical analysis was carried out regarding the frequency, quantity, average frequency, and frequency variance of each category of the keywords. A total of 3459 Chinese keywords and 9128 English keywords formed the basis of this analysis. According to the ﬁndings, China is the most frequently studied geographical region in the international tourism research. The application of qualitative methods in the Chinese tourism research is less frequent than that in the international research, and the combination of qualitative and quantitative methods has become an important trend in tourism research. The international tourism research on certain topics is more in-depth and cutting-edge than the Chinese tourism research.


Introduction
The theoretical system and knowledge framework of the tourism discipline have continued to generate attention and controversy in the academic circles studying tourism [1]. Over the years, the number of publications in the Chinese and English journals has increased. Meanwhile, under the influence of various social, economic, environmental, political, and other factors, many hot topics have emerged in the Chinese and international tourism research in the past ten years, and the themes and methods of tourism research have changed. As one of the most influential events of the 21st century, the coronavirus (COVID-19) pandemic has had an extremely large impact on the tourism industry and tourism research [2]. Therefore, it is necessary to explore the situation and the knowledge structure of global tourism research in the recent years.
With China entering a New Normal era, the quality and international influence of the Chinese tourism research has greatly improved [3]. With the vigorous development of tourism, tourism research in China has been growing for more than 40 years [4][5][6][7]. The Chinese tourism research has become established in many academic institutions; the research results have continued to increase, research directions and fields have continued to expand, and the content of research has deepened. The academic papers on tourism in China are gradually becoming more professional, more diverse and more application-oriented [1]. However, because the Chinese tourism research started late and is still in the development stage, it is of significance to clarify the current gap between the international and Chinese tourism research. Lately, many scholars have classified and analyzed the research results of the Chinese or international tourism over different periods, but few studies have provided a comparative analysis of the Chinese and international tourism research from the perspective of global tourism studies. This research will select Chinese and English journals, bridge the Chinese and international academic literature on tourism, compare the similarities and differences between the Chinese and international tourism studies by constructing tourism research knowledge domains. This research will explore the following questions: Over the past decades, there have been a significant growth and evolution of tourism studies, which have become the focus of academic scholars' interests around the world. International tourism research is dating back to more than 50 years and refers to more than 100 existing journals [8]. At present, many studies select journals as the main research objects to analyze and review the characteristics of tourism research in a certain period from the perspectives of journal publications [9], article citations [10], research topics [11,12], research methods [13], authors [14], etc. Some of these studies are the evaluations of the research output and the impacts made by researchers and institutions [8,9,14], other studies analyze the subject areas and research trends [12,15], and few studies examine the tourism knowledge structure [16,17]. The above studies mainly use bibliometric methods including content analysis, co-citation analysis, co-authorship analysis, bibliographic coupling, and co-word analysis [8,18,19]. The selected journals are mainly Annals of Tourism Research, Tourism Management, Journal of Travel Research, Journal of Sustainable Tourism [20], and some studies are based on databases [21,22]. The research period that has been analyzed ranged in duration from 5 to 40 years [19]. There are also a few studies that are the author's direct discussions of the development process of tourism research, which require scholars to have a relatively mature academic foundation. For example, Airey [23] plots the past, present, and future of the tourism studies by drawing from his own 40 years in the tourism academy and his writings over the period. Ryan [24] envisions the future of tourism research and Tourism Management perspectives by focusing the discussion on the changes in universities, and the processes of publication and the tourism itself. Lately, there have been also many review studies focusing on a certain topic or method, which have provided in-depth explorations of research progress pertaining to a certain tourism phenomenon [2], tourism type [25,26], or tourism research method [27].

Analysis of the Progress of Chinese Tourism Research
The comprehensive reform and opening up in 1978 created a new situation for the development of the Chinese tourism. This enabled vigorous development of the Chinese tourism industry and prompted the initiation and growth of the Chinese tourism research that has now flourished for approximately 40 years. Inevitably, there was an initial gap between the Chinese and international tourism research, but the former has been enhanced significantly in recent years, and the analysis of the knowledge system and the academic progress of the Chinese tourism research has become more comprehensive and systematic [28]. Most of the early papers were written by local Chinese scholars and published in Chinese or in English in international journals [28][29][30]. Others were written by foreign scholars and published in English [31]. Chinese scholars mainly focused on the international influence of the Chinese tourism research [32][33][34][35], the influence of the Chinese tourism academic journals [36][37][38], the evaluation of academic papers in the Chinese academic journals [29,[39][40][41][42] and the trends and characteristics of international tourism research [43]. A small number of scholars conducted comparative analyses between the Chinese and international tourism research [44][45][46][47]. The research objects were mainly academic journals [35,41,[48][49][50][51][52], dissertations [53], funded projects [54,55], etc. Journal articles are the most important outlets for research results, and the most innovative research achievements receive the highest social recognition and most frequent citation [4]. These tourism journals mainly included Tourism Journal, Tourism Science, Tourism Forum, etc. Most research has focused on the number and frequency of publications [32,43], research fields and topics [37,48,50], research methods, research areas [43,53], author information [45], citation [34], etc. Most of such papers on the Chinese research have been descriptive, and although there have been attempts to use quantitative methods, they have not been comprehensive.
The publication of Chinese tourism research is now changing rapidly. Many young Chinese scholars have studied abroad, are familiar with foreign languages, especially English, and have access to the most recent international research electronically [3]. Thus, they have become more familiar with international research and able to contribute to it. At the same time, the top institutions in the in China have placed greater emphasis on publication in international journals, and the reward system encourages this [56]. Thus, publications by the Chinese scholars, as single authors, as part of research teams, and in collaboration with foreign scholars, have proliferated in recent years. Indeed, as a large country with massive tourism flows, large international and domestic tourism involvement, and numerous tourism researchers aspiring to publish their research, the Chinese research and researchers have become prominent in the international tourism research, including the content of major international academic tourism journals.

Research on the International Tourism Knowledge Domain
Knowledge development of tourism studies have long been an area of interest for academics in this multidisciplinary community [57]. Many studies have identified the major subject areas of tourism research based on the research themes of published articles. Wickham and Dunn [58] discovered 50 tourism research themes by coding the themes of all articles in the leading tourism journals from 1999-2008, and among them, the 10 most frequently coded themes accounted for 82.3% of the total articles published. In addition, longitudinal subject areas exploration has attracted the attention of scholars. Xiao and Smith [18] split 30 years into six five-year periods and examined changes in subject areas in each of the time periods. Two subject domains were observed: (1) methodology and theory and (2) development and impacts. Ballantyne et al. [12] divided the research into three time periods (1994-1997, 1998-2001, and 2002-2005) and explored the differences between the topics and journals. Nonetheless, as a potential drawback, it has been suggested that the use of subject headwords to examine the research progress has the "filtered" effect imposed by cataloging systems or index editors [59]. Author keywords, as an article best represent the subjects or topical coverage as well as the methodology and geographical specialization of a publication, have also gradually attracted the attention of researchers in recent years. Correia and Kozak [22] presented scientific areas, theory, methods, and places covered in the publication from 1947 to 2020 through the keywords network analysis. Wu et al. [59] examined author-selected keywords of research published in Annals of Tourism Research, Journal of Travel Research, and Tourism Management and provided a framework for the interrelationship between the tourism phenomenon and tourism essence in the tourism research and practice according to core keywords and gene keywords ( Figure 1). Different from the above, Xiao and Smith [16] discussed the patterns of source knowledge for tourism research by describing major characteristics of citations used in the articles of Annals of Tourism Research. Benckendorff and Zehrer [60] obtained the contribution potential of different disciplines in tourism research from the perspective of the authors of representative papers. In addition, some studies adopted philosophical approaches. Tribe and Liburd [17] built a model of the tourism knowledge system on the basis of epistemology and ontology, which was regarded as subjective.  [60] obtained the contribution potential of different disciplines in tourism research from the perspective of the authors of representative papers. In addition, some studies adopted philosophical approaches. Tribe and Liburd [17] built a model of the tourism knowledge system on the basis of epistemology and ontology, which was regarded as subjective.

Research on the Chinese Tourism Knowledge Domain
The tourism knowledge system has always been a popular topic in China's domestic academia, and there is ongoing debate on whether or not tourism should exist as an independent discipline. Xie [61] proposed that tourism research is typically interdisciplinary. Regarding research on the tourism knowledge domain, most scholars have taken article keywords as data and used bibliometric and content analysis methods to analyze the composition, research themes, or evolution of the tourism knowledge system [41,49,62]. Some have provided visual and graphical portrayals to summarize information and identify future research topics [63][64][65][66], Zhang et al. [33] divided tourism knowledge into 13 categories, including tourism theory and research, tourism geography, tourism planning, tourism public management, tourism education, tourism roads and traffic, tourism environment, tourism psychology, tourism marketing, tourism information and its utilization, tourism law, tourism economy, destinations, and regional tourism development. Based on the publications in Tourism Tribune from 1986 to 2016, Wang et al. [49] divided tourism research into theory and method, tourism management, tourism resource development and evaluation, tourism education and training, tourism reception, tourism destinations, literature research, tourism market, tourists, etc. These studies focused on high-frequency keywords and essentially ignored low-frequency keywords. The tourism knowledge system arising from such work can be presented simply as consisting of four parts: research content, method, geographic area, and purpose. By merging, sorting, and grouping the keywords, Dong X. et al. also arrived at a knowledge system framework consisting of four major parts: research subject, geographic area, research method, and knowledge domain ( Figure 1) [50].

Research on Comparison of Chinese and International Tourism Research
At present, there have been some comparative studies on the Chinese and international tourism research in both English and Chinese journals. Most of them were published by authors from China, some were co-published by authors from multiple countries

Research on the Chinese Tourism Knowledge Domain
The tourism knowledge system has always been a popular topic in China's domestic academia, and there is ongoing debate on whether or not tourism should exist as an independent discipline. Xie [61] proposed that tourism research is typically interdisciplinary. Regarding research on the tourism knowledge domain, most scholars have taken article keywords as data and used bibliometric and content analysis methods to analyze the composition, research themes, or evolution of the tourism knowledge system [41,49,62]. Some have provided visual and graphical portrayals to summarize information and identify future research topics [63][64][65][66], Zhang et al. [33] divided tourism knowledge into 13 categories, including tourism theory and research, tourism geography, tourism planning, tourism public management, tourism education, tourism roads and traffic, tourism environment, tourism psychology, tourism marketing, tourism information and its utilization, tourism law, tourism economy, destinations, and regional tourism development. Based on the publications in Tourism Tribune from 1986 to 2016, Wang et al. [49] divided tourism research into theory and method, tourism management, tourism resource development and evaluation, tourism education and training, tourism reception, tourism destinations, literature research, tourism market, tourists, etc. These studies focused on high-frequency keywords and essentially ignored low-frequency keywords. The tourism knowledge system arising from such work can be presented simply as consisting of four parts: research content, method, geographic area, and purpose. By merging, sorting, and grouping the keywords, Dong X. et al. also arrived at a knowledge system framework consisting of four major parts: research subject, geographic area, research method, and knowledge domain ( Figure 1) [50].

Research on Comparison of Chinese and International Tourism Research
At present, there have been some comparative studies on the Chinese and international tourism research in both English and Chinese journals. Most of them were published by authors from China, some were co-published by authors from multiple countries [67]. As reflected in many of the existing articles about comparative research, the Chinese and international tourism studies focused on certain types of tourism, including cruise tourism [68], religious tourism [69], adventure tourism [67], heritage tourism [70], ocean tourism [71], sports tourism [72], cultural tourism [73], medical tourism [74], rural tourism [75], eco- logical tourism [76], etc. These studies provided a differential comparison between the Chinese and Western tourism research in terms of the number of publications, authors, research topics, research areas, research methods, research ideas, and other aspects based on bibliometric method, content analysis method, comparative method, text mining method, word frequency analysis method, etc. These studies built a bridge between the Chinese and Western academic publications, as Cheng [67] said, the first step to establish a global perspective of adventure tourism is to review the Chinese literature. There were also some studies focusing on themes including tourism interpretation, poverty alleviation tourism, tourism soundscape, and the Chinese culture [77][78][79][80]. Li [77] used the CiteSpace software to analyze the co-linearity of keyword networks and compared the theoretical basis and research areas of the research literature on tourism interpretation at home and abroad. Sun et al. [78] conducted a comparative study on the research topics of poverty alleviation tourism at home and abroad from research topics and evolution of research themes and study areas of cases based on the social network analysis of keywords.
In addition, some studies selected Chinese and English tourism journals as objects and compared differences between the Chinese and Western tourism research. Zhu and Liu [81] selected the articles from Annals of Tourism Research and Tourism Tribune during 2000-2004 as research objects, classified and calculated statistics on all articles according to their research content, research methods, and research depth, and analyzed the differences and similarities. It was found that Tourism Tribune mainly studied tourism economy and management and development and planning of tourism resources, and Annals of Tourism Research focused on the impact of tourism, tourist behavior and market, and tourism theory and methods. In research methods, descriptive research methods are most commonly used in the papers published in Tourism Tribune, while mathematical statistics are the main research methods in the papers published in Annals of Tourism Research. In research depth, Western scholars have more extensive research fields and more in-depth research, and their conclusions are mostly verified by facts. We can find that from 2000 to 2004, there was still a big gap between the Chinese and international tourism research. The Chinese tourism discipline has not formed a complete and systematic discipline system, and some theories need to be strengthened. Wang et al. [82] selected six Chinese and English core journals including Journal of Geographical Sciences, Scientia Geographica Sinica, Geographical Research, Annals of Tourism Research, Journal of Travel Research, and Tourism Management and compared and analyzed the diachronic evolution characteristics of tourism research of the Chinese and international tourism studies during 1980-2009. The conclusions showed that there are obvious differences in the degree of attention of the Chinese and international studies on the nine research fields: the international tourism research paid more attention to tourism management, tourism policy, tourism education and training, tourism reception, tourism transportation, business tourism and leisure tourism, while the Chinese research paid more attention to tourism spatial structure and tourism resource development. In research methods, the proportion of quantitative research methods, qualitative research methods, and qualitative-and-quantitative-combination methods in the international tourism research is 59%, 19%, and 6%, respectively, and the literature review method accounts for 16%. In contrast, the Chinese tourism research is dominated by quantitative methods, accounting for 69.2% of the total literature, while qualitative methods only play an auxiliary role. With respect to the research area, the international tourism research area is mainly a single country, and Europe, North America, Oceania, and Asia are the hot areas. The Chinese tourism research mainly focused on a single region and the hot tourist attraction in China. Xu [83] selected three English journals: Annals of Tourism Research, Journal of Travel Research, and Tourism Management, analyzed and compared the overall strength of Chinese and international tourism research, as well as the strength of tourism research of continents/provinces, tourism research institutions and scholars. The conclusions showed that both the international tourism research and Chinese tourism research have developed rapidly. North America and Europe rank first among the seven continents in tourism research strength. In the discussion on the causes of the differences between the Chinese and international tourism studies, the characteristics of journals, tourism development level, starting time of tourism research, research education, scholars' research habits, etc., were summarized [81,83].
In sum, both the Chinese and international researchers have been paying attention to reviewing the existing research and empirical evidence in support of the arguments generated through bibliometric investigations. However, the systematization of knowledge is lacking attention, especially from the cross-cultural research perspective. In addition, there has been an increase in publications dedicated to the modern tourism research that takes into account "the new era" situation. Therefore, it would be timely to constructed a knowledge domain framework based on the evolved international tourism.

Data Collection
Keywords are indispensable requirements in academic research papers. They reflect and summarize the article's themes, provide a very concise and accurate description of the contents of the article. The keywords reveal the main topics covered by the article [48] in a highly condensed form. In this study, the Elsevier Science full-text database, CPCI database and CNKI database were used to conduct searches. All articles published from 2012 to 2021 in four authoritative journals-Annals of Tourism Research, Tourism Management, Journal of Sustainable Tourism, and Tourism Tribune-were included. Conference reports, journal annual summaries, and articles without keywords were excluded. While the examination of all the tourism-related journals would provide a comprehensive picture of the current state of research, it would be unrealistic to execute such a study, and the results would be somewhat redundant to the existing research [84]. Thus, in order to provide meaningful and succinct results, the scope of this study is limited to the aforesaid four journals.
The Tourism Tribune is one of the core journals in China to publish tourism-related studies [85]. It has been consistently rated as the Chinese leading journal in the field [50,86] and therefore frequently used as a single data source to reflect on the progress of tourism research in China [50,81,86]. The Annals of Tourism Research, Tourism Management, and Journal of Sustainable Tourism are influential journals in the tourism field with these journals having a 2022 impact factor of 9.011,10.967, and 7.968, respectively. The Annals of Tourism Research is acknowledged as one of the leading scholarly journals in the field [16]. The Tourism Management is another leading international journal with an interdisciplinary approach which includes the planning and policy aspects of tourism as well as specific management studies [87]. These two journals are often selected as research data sources in the tourism bibliometric analysis [16,18,59]. The Journal of Sustainable Tourism in the field of tourism have gained prominence over the years. It is the main journal in "Geography, Planning and Development", and many studies about sustainable tourism select it as a research object [88][89][90].
The database studied in this paper consists of all the article keywords from the above four journals. Keyword collection ended on 1 April 2021. The numbers of articles and keywords in each journal are shown in Table 1. Finally, 5132 Chinese keywords from 1204 Chinese articles and 18,583 English keywords from 3584 English articles were obtained.

Data Processing
It was first necessary to standardize keywords and address inconsistencies or irregularities in the keyword database to facilitate subsequent statistical analysis.

Data Overview
After repeated processing, 3459 unique Chinese keywords were obtained which appeared 5132 times, as well as 9128 unique English keywords with 18,583 mentions. Chinese keywords appeared 1.48 times on average. English keywords appeared 2.04 times on average.
The keywords were arranged in descending order according to their frequency of appearance to reveal typical power law distributions ( Figure 2). Most keywords were researched few times. Most articles that were based on the quantitative analysis of keywords selected only high-frequency keywords [44][45][46]48], that is, core keywords. There was little research on the keywords that rarely appeared. However, the overall benefits of low-frequency keywords are comparable to the high-frequency keywords, and even exceed those of the high-frequency keywords. Therefore, this research will comprehensively analyze 3459 Chinese keywords and 9128 English keywords and further explore the knowledge domain of the Chinese and international tourism research in a more in-depth and detailed manner.

Data Coding and Analysis
According to the research themes and content reflected in the keywords combined with the tourism knowledge structure constructed by the Chinese and international tourism scholars in previous studies, the keywords (except for "tourism") were divided into "research areas", "research objects", "research methods", and "research disciplines" (Fig-Figure 2. Scatter plot and its power law distribution of keywords in a Chinese and international tourism journal and international tourism journals.

Data Coding and Analysis
According to the research themes and content reflected in the keywords combined with the tourism knowledge structure constructed by the Chinese and international tourism scholars in previous studies, the keywords (except for "tourism") were divided into "research areas", "research objects", "research methods", and "research disciplines" (Figure 3). The coding work was based on a full understanding of the previous scholars' classification criteria for the keywords. Initially, the first author completed the classification independently and labelled the keywords that were difficult to classify. These were then discussed with the second author who verified the coding of all keywords.

Data Coding and Analysis
According to the research themes and content reflected in the keywords combined with the tourism knowledge structure constructed by the Chinese and international tourism scholars in previous studies, the keywords (except for "tourism") were divided into "research areas", "research objects", "research methods", and "research disciplines" (Figure 3). The coding work was based on a full understanding of the previous scholars' classification criteria for the keywords. Initially, the first author completed the classification independently and labelled the keywords that were difficult to classify. These were then discussed with the second author who verified the coding of all keywords. Four categories of main statistical indicators guide data interpretation: (1) the number and percentage of each category of keywords reflect the breadth of a research category; (2) the frequency of each category of keywords (the total number of occurrences of all keywords in a category) and its percentage reflect the amount of attention devoted to the research subject; (3) the average frequency of each category of keywords, i.e., the ratio of the frequency of all keywords to the number of keywords, reflects the depth of the research; and (4) the variance of each category of keywords indicates the degree of concentration found within a research category. On the basis of the above-mentioned statistical analysis, CiteSpace was used to analyze and compare the ten-year timeline and emergent keywords of the Chinese and international tourism research. (2) the frequency of each category of keywords (the total number of occurrences of all keywords in a category) and its percentage reflect the amount of attention devoted to the research subject; (3) the average frequency of each category of keywords, i.e., the ratio of the frequency of all keywords to the number of keywords, reflects the depth of the research; and (4) the variance of each category of keywords indicates the degree of concentration found within a research category. On the basis of the above-mentioned statistical analysis, CiteSpace was used to analyze and compare the ten-year timeline and emergent keywords of the Chinese and international tourism research.

Overview of Chinese Tourism Research Knowledge Domain
Based on the above four indicators, a comprehensive analysis of the Chinese tourism research knowledge domain was conducted ( Table 2). The quantity and frequency of keywords for tourism marketing and business administration, tourism public administration and tourism politics, tourism sociology, and tourism anthropology are relatively high, but the keyword frequency variance is small, indicating that these types of research focus on a relatively narrow range of topics. Tourism marketing and business administration have the largest quantity and frequency of keywords, while tourism ecology and sustainable development have the least number and lowest frequency of keywords. However, in terms of average frequency and variance, tourism stakeholders scores quite high, suggesting strong interest in this topic in a diversity of circumstances and scholars are lack of agreement on what is important. Tourism economics is substantial in frequency and relatively Sustainability 2023, 15, 9151 9 of 25 narrow in focus. The frequency and average frequency of keywords in tourism psychology and tourist behavior, tourism geography and tourism planning are relatively high, and the frequency variance is also high, indicating strong interest and diverse perspectives on these topics. The quantity and frequency of keywords in tourism research and tourism education are relatively small, and the frequency variance is high, suggesting less activity and diversity of perspectives. Among all the Chinese keywords except "tourism", 4.8% (166) of the keywords are geographical keywords and reflect the importance of a spatial unit. China, a large geographic area, has the most mentions, with 18 occurrences, much higher in frequency than other regions. This probably reflects the importance of a national focus. The keywords can be divided into three categories: domestic, domestic and overseas, and overseas (Table 3). Domestic research is by far the most common, and minimal research is reported to have been undertaken elsewhere. If the 166 geographic region keywords are classified according to six different spatial scales (global, national, regional, provincial, city, local) (Table 4), then, in general, the smaller the spatial scale, the greater the quantity and frequency of keywords; the larger spatial scale, the lesser the quantity and frequency of keywords ( Figure 4). The important sites of the Chinese tourism research are mainly domestic, medium-and small-scale geographic spaces, where case studies have been undertaken. If the 166 geographic region keywords are classified according to six different spatial scales (global, national, regional, provincial, city, local) (Table 4), then, in general, the smaller the spatial scale, the greater the quantity and frequency of keywords; the larger spatial scale, the lesser the quantity and frequency of keywords (Figure 4). The important sites of the Chinese tourism research are mainly domestic, medium-and small-scale geographic spaces, where case studies have been undertaken.  Next, we further divided the domestic keywords according to the province and explored the degree of attention of the Chinese tourism academia to the tourism of various Next, we further divided the domestic keywords according to the province and explored the degree of attention of the Chinese tourism academia to the tourism of various provincial administrative regions in China. It was found that Yunnan, Guangdong, and Sichuan appeared more frequently, followed by Hunan and Fujian and others ( Figure 5). provincial administrative regions in China. It was found that Yunnan, Guangdong, and Sichuan appeared more frequently, followed by Hunan and Fujian and others ( Figure 5).

Analysis of Research Objects in Chinese Tourism Research
There are 367 keywords related to the research object in the Chinese tourism research, with a total frequency of 758 (accounting for 14.77% of the total keyword frequency). Many stakeholders are involved in tourism. The high-frequency keywords in this category are mainly hotels (30), tourism enterprises (25), tourists (21), travel agencies (9), residents (8), tourism companies (8), and tourism community (8). The word "stakeholders" appeared seven times. There are 153 keywords related to the tourism industry and attractions, with a total frequency of 297, including 31 mentions of "tourism industry". The high-frequency keywords of "tourism industry" are tourist attractions (7), hotel industry

Analysis of Research Objects in Chinese Tourism Research
There are 367 keywords related to the research object in the Chinese tourism research, with a total frequency of 758 (accounting for 14.77% of the total keyword frequency). Many stakeholders are involved in tourism. The high-frequency keywords in this category are mainly hotels (30), tourism enterprises (25), tourists (21), travel agencies (9), residents (8), tourism companies (8), and tourism community (8). The word "stakeholders" appeared seven times. There are 153 keywords related to the tourism industry and attractions, with a total frequency of 297, including 31 mentions of "tourism industry". The high-frequency keywords of "tourism industry" are tourist attractions (7), hotel industry (6), and cruise industry (6). The high-frequency keywords for "tourist attractions" are tourist destinations (25), tourist spots (7), tourist attractions (7), homestays (7), cruise (6), ancient towns (5), and theme parks (5). The total frequency of keywords in tourism and leisure activities is 225 times, accounting for 4.38% of the total frequency of keywords. Rural tourism has become a research focus, with 21 occurrences. Other tourism forms include outbound tourism (12), inbound tourism (10), cruise tourism (8), city tourism (6), cultural tourism (6), heritage tourism (6), dark tourism (5), and red tourism (5), in which "leisure" appears as a keyword nine times.

Analysis of Research Methods and Theories in Chinese Tourism Research
There are 236 keywords reflecting research methods and theories, with a total of 406 occurrences. Quantitative methods include content analysis (17), social network analysis (17), structural equation model (16), panel data model (13), quantitative table development (7), cluster analysis (6), data envelopment analysis (6), emphasis and performance analysis (6), and other methods. Among qualitative methods, grounded theory (26) has the highest frequency. Empirical research (6) has the highest frequency among traditional descriptive or conceptual analytical methods. While a variety of qualitative or quantitative research methods is used in the Chinese tourism research, quantitative research is more frequent.

Analysis of Research Disciplines in Chinese Tourism Research
The keywords of tourism psychology in Chinese are tourism experience (28), tourist behavior (12), tourist satisfaction (12), behavior intentions (10), place attachment (9), and perceived value (8). Among tourism sociology and tourism anthropology research topics, modernity (11), tourism flow (10), phenomenology (9), authenticity (9), community participation (7), mobility (6), and gaze (6) are paid most attention. The keywords "tourism sociology" and "tourism anthropology" each appear only once. The main keywords of tourism economics are economic growth (12), tourism economy (7), and total factor productivity (5). "Tourism research" appears 15 times, and "research literature" has the highest frequency with 26 mentions, followed by research progress (14), enlightenment (7), and tourism discipline (6). Tourism Tribune, a journal with a high status in the Chinese tourism academia, appears three times as a keyword. In tourism public management and political science, phrases such as tourism contracts (6), tourism law (5), and social capital (5) are most frequent, followed by keywords related to the policy system, such as institutional changes (3), policies (2), and institutional environment (2). In tourism marketing and business management, destination image (14) appears the most, and there are other topics such as big data (6), tourism APP (5), tourism products (5), and tourism commercialization (5). The main research topics of tourism geography and tourism planning are influencing factors (24), tourism development (15), tourism impact (10), online tourism (7), and natural disasters (6). "Tourism planning" appears four times as a keyword. There are few high-frequency keywords in tourism ecology and sustainable development, and these are low-carbon tourism (6), carbon dioxide emissions (6), environmentally responsible behavior (6), and sustainable development (5).

Overview of International Tourism Research Knowledge Domain
Tourism marketing and business administration have the largest quantity and frequency of keywords, while the quantity and frequency of keywords for tourism research and tourism education, tourism ecology and sustainable development, and tourism economics are relatively low. Their research topics and content are singular and, compared with other categories, research attention is not high. The average frequency of tourism ecology and sustainable development is the highest at 4.05, indicating the focus on this topic. However, the frequency variance of keywords in each category is very high, and is the highest in tourism ecology and sustainable development, indicating that such terms embrace a wide variety of topics (Table 5).

Geographical Analysis of International Tourism Research
Among all English keywords other than "tourism", 369 keywords identify geographical locations. Among them, "China" appears 107 times, the highest frequency, indicating that the international tourism research pays considerable attention to China's tourism as its source, as the market and origin of tourism research have grown. The phrase "developing countries" appears 10 times.
When the 369 keywords are classified according to different spatial scales (Table 6), it is found that the quantity and frequency of keywords at the national scale are much higher, indicating the importance of national-scale spaces in the international tourism research. Descriptive statistical information on tourism is widely available at this scale. Other scales are well represented but with a large number of investigations at the local scale, reflecting the large number of site-specific case studies. Further analysis of 336 keywords that identify research location enables identification of the degree of attention paid to the tourism development of each country by the international tourism academia. Among them, keywords involving China appeared 227 times, ranking first in the keyword list, followed by Australia (41), India (38), the United States (36), Spain (32), and the UK (28) ( Table 7).   (7), Cambodia (7), African Republic of Ghana (7), Republic of Ecuador (7), Russia (7), Chile (6) Then, after removing the keywords that could not be classified according to continent, such as developing countries and underdeveloped areas, the remaining 344 keywords were further classified. Asia and Europe have the greatest number of keywords and the highest frequency of occurrence, 457 and 206 times, respectively. There are fewer studies on Oceania and Antarctica (Table 8).

Analysis of Research Methods and Theories in International Tourism Research
There are 616 keywords reflecting tourism research methods and theories, with a total frequency of 1282. Research method (6), research approach (1), and approach (1) appear eight times as keywords. Other high-frequency keywords include structural equation model (32), importance and performance analysis (27), content analysis (24), planned behavior theory (21), user-generated content (19), hybrid analysis method (18), indicators (18), qualitative research (15), data mining (14), and ethnography (12). Many types of methods, including both qualitative and quantitative analysis applications, are found in international research.

Comparative Analysis of All Keywords in Chinese and International Tourism Research
Reflecting the number of journals selected for this study, the quantity of keywords in the Chinese tourism research is 3459 compared to 9128 in the three international journals combined. The average frequency of keywords is 1.48 for the Chinese tourism research, and 2.04 for the international tourism research, suggesting a greater depth of the international research.

Comparative Analysis of Geographic Areas in Chinese and International Tourism Research
The geographic areas in the Chinese tourism research are mainly located in China, with a frequency of 154 times or 92.77%, whereas the international tourism research covers diverse locations. Nevertheless, 227 of the keywords in the international tourism research involve China, the highest among all countries or 23.23%, indicating that China has received considerable attention in the international tourism research. The case sites involved in the Chinese tourism research are mainly local and city-level geographic spaces, whereas national-scale geographic spaces are more common in the international research.

Comparative Analysis of Research Objects in Chinese and International Tourism Research
In terms of stakeholders in the tourism industry, both the Chinese and international tourism research mainly focuses on tourism enterprises, tourists, communities, residents, and governments. The international research also pays more attention to volunteers. With respect to the tourism industry, the Chinese tourism research pays more attention to the hotels, cruises, and exhibition industries, whereas the international research also pays attention to local tourism and agricultural tourism. In the context of attractions, the Chinese tourism research focuses on tourist destinations, scenic spots, folk customs, cruise ships, ancient towns, theme parks, cultural heritage, etc. In comparison, the international tourism research gives more attention to national parks (which are a recent development in China), festivals, cultural heritage, and souvenirs. Regarding tourism activities, heritage tourism, dark tourism, urban tourism, and cruise tourism are represented in both the Chinese and international tourism research. Rural tourism, inbound and outbound tourism, cultural tourism, and red tourism have attracted more attention from Chinese scholars, whereas wildlife tourism, community tourism, medical tourism, and pilgrimage tourism have been addressed more frequently by international scholars.

Comparative Analysis of Research Methods in Chinese and International Tourism Research
A wider variety of research methods is used in the international compared to the Chinese tourism research, and qualitative research is less widely employed in the latter, focusing on grounded theory and content analysis. The combination of qualitative and quantitative methods has become an important trend, especially in the international tourism research.

Comparative Analysis of Research Disciplines in Chinese and International Tourism Research
Regarding tourism psychology, both the Chinese and international tourism academics are interested in experience, satisfaction, intention, attachment, motivation, and perception. International scholars have conducted more research on happiness, emotion, trust, and loyalty, while the Chinese scholars have been more inclined to address "value". The research topics on tourist behavior in the Chinese tourism research are narrow, focusing on tourism behavior and behavior intention. In the international literature, there are also many studies of tourism demand, willingness to pay, behavior change, and decision making. With respect to tourism sociology and anthropology, community participation and authenticity are of interest to both the Chinese and international tourism researchers, with the frequency of "authenticity" ranking first in the international tourism research. There are few high-frequency keywords in the Chinese and international tourism economics research, with "economic growth" receiving the most attention. Regarding education, the most common keywords are research review, tourism research, and research progress, involving many other keywords, while the international tourism research focuses on interpretation, knowledge, reflexivity, and review. In the case of public administration and tourism politics, "social capital" appears frequently in both the Chinese and international tourism research, but there are more studies on tourism contracts, laws, and mechanisms in the Chinese tourism research. In contrast, the international tourism research highlights management, governance, power, and policy. With respect to marketing, the international tourism research focuses on destination images, social media, and online reviews. The Chinese research is similar with frequent mentions of destination images, tourism apps, tourism websites, and brands. With respect to business management, there are many studies on corporate social responsibility, big data, and service quality by the Chinese and international tourism academia. With respect to the tourism geography and tourism planning, planning, influence, and development are common topics. International academia pays considerable attention to climate change, whereas the Chinese tourism research focuses more on natural disasters, spatial structure, and high-speed railways. However, with respect to tourism ecology and sustainable development, there are comparatively few highfrequency keywords in the Chinese tourism research, and these are low-carbon tourism, carbon dioxide emissions, and environmental responsibility behavior, whereas "sustainable tourism development" appears in the international tourism research 187 times, most often excluding the word "tourism", as well as topics such as sustainability, ecotourism, political ecology, and vulnerability.

Timeline Map and Emergent Keyword Analysis of Chinese Tourism Research
CiteSpace software that is used to provide a visual representation of keywords [91,92]. In this paper, CiteSpace is used to generate temporal clusters in the use of keywords in four journals over the past ten years.
Using the CNKI database, data on articles in Tourism Tribune for 2012-2021 were analyzed annually to generate a keyword timeline clustering graph (Figure 6), and nine clusters were formed. Tourism destination and rural tourism are the research categories with a long time span. The central keywords of rural tourism in different periods are rural tourism, tourist gaze, sense of place, and rural gentrification. The two categories of tourist behavior and research progress received attention from 2012 to 2020, the central keywords are tourist behavior, social media and literature review, content analysis, social network analysis, knowledge system. Grounded theory appeared in 2013, reflecting the application of qualitative methods in China in the past decade. After 2017, there were few studies on the clusters of economic growth. The attention of research reviews and tourist satisfaction studies decreased in 2019, with the tourist flow and tourist loyalty being the central keywords for tourist satisfaction. The research on destination image has increased since 2014 and is still attracting the attention of Chinese scholars. On this basis, through the "Burstiness" option, we obtained the emergent keywords ( Figure 7). Tourism destination, tourist behavior, grounded theory, and rural tourism are the keywords with high intensity of emergence, and their strength is above 3.10.

Timeline Map and Emergent Keyword Analysis of Chinese Tourism Research
CiteSpace software that is used to provide a visual representation of keywords [91,92]. In this paper, CiteSpace is used to generate temporal clusters in the use of keywords in four journals over the past ten years.
Using the CNKI database, data on articles in Tourism Tribune for 2012-2021 were analyzed annually to generate a keyword timeline clustering graph (Figure 6), and nine clusters were formed. Tourism destination and rural tourism are the research categories with a long time span. The central keywords of rural tourism in different periods are rural tourism, tourist gaze, sense of place, and rural gentrification. The two categories of tourist behavior and research progress received attention from 2012 to 2020, the central keywords are tourist behavior, social media and literature review, content analysis, social network analysis, knowledge system. Grounded theory appeared in 2013, reflecting the application of qualitative methods in China in the past decade. After 2017, there were few studies on the clusters of economic growth. The attention of research reviews and tourist satisfaction studies decreased in 2019, with the tourist flow and tourist loyalty being the central keywords for tourist satisfaction. The research on destination image has increased since 2014 and is still attracting the attention of Chinese scholars. On this basis, through the "Burstiness" option, we obtained the emergent keywords ( Figure 7). Tourism destination, tourist behavior, grounded theory, and rural tourism are the keywords with high intensity of emergence, and their strength is above 3.10.

Timeline Map and Emergent Keyword Analysis of International Tourism Research
Similarly, using the WOS core database, data for Annals of Tourism Research, Tourism Management and Journal of Sustainable Tourism for 2012-2021 were analyzed using CiteSpace to obtain a cluster graph (Figures 8 and 9). With respect to the hotel industry clusters, central keywords include management, performance, sharing economy, etc. In the category of tourism demand, female tourist attracted attention in 2012. In addition, the keywords such as policy, risk, and country also have a high degree of centrality. In the category of protected areas, ecotourism, sustainability, community, and conservation attracted the attention of international scholars in 2012, and wildlife tourism became the central keywords in 2016. With respect to the international research, destination image started in 2012 or earlier, and main keywords include destination loyalty, intention, etc. Other clusters include tourism policy, tourist experience, social exchange theory, prospect theory, and social media. From the view of keyword emergence, the intensity of these keywords is all above 3.80 (Figure 9). Moderating role, sharing economy, time series, ac-

Timeline Map and Emergent Keyword Analysis of International Tourism Research
Similarly, using the WOS core database, data for Annals of Tourism Research, Tourism Management and Journal of Sustainable Tourism for 2012-2021 were analyzed using CiteSpace to obtain a cluster graph (Figures 8 and 9). With respect to the hotel industry clusters, central keywords include management, performance, sharing economy, etc. In the category of tourism demand, female tourist attracted attention in 2012. In addition, the keywords such as policy, risk, and country also have a high degree of centrality. In the category of protected areas, ecotourism, sustainability, community, and conservation attracted the attention of international scholars in 2012, and wildlife tourism became the central keywords in 2016. With respect to the international research, destination image started in 2012 or earlier, and main keywords include destination loyalty, intention, etc. Other clusters include tourism policy, tourist experience, social exchange theory, prospect theory, and social media. From the view of keyword emergence, the intensity of these keywords is all above 3.80 ( Figure 9). Moderating role, sharing economy, time series, accuracy are the themes of rapid growth in the international tourism research in recent years.

A Comparative Analysis of Chinese and International Tourism Research Progress
Through the analysis of timeline map and emergent keywords of the Chinese and international tourism research, it is found that there are similarities between the Chinese and international tourism research themes, and there are differences in the time change of research hotspots. For example, destination image is an important clustering topic in the Chinese and international tourism research, but the research on this topic in China is later than that in the West. During 2012-2021, both the Chinese and international tourism studies pay more attention to tourists. The Chinese tourism studies focus on tourist behavior, while the international tourism studies focus on tourist experience. Research progress and rural tourism are important aspects of the Chinese research, while the international tourism research pays more attention to such topics as protected areas, ecotourism, and tourism demand.

Discussion and Conclusions
Although there are some common keywords in the Chinese and international tourism research, the topics covered in the international tourism research are more varied, more mature in the application of theories and methods, and more likely to be on the extensive and cutting edge of research. This is not to disparage the Chinese tourism research, for it started later, and some Chinese scholars choose to publish their best work in prestigious international outlets.
Naturally, the Chinese journal emphasizes the Chinese content, whereas the international journals draw upon and serve the international clientele. However, China has become the most discussed topic in the international tourism research. Liu et al. [43] also found that China has become a focus of much tourism research, and the amount of literature with the keyword "China" soared after 2008. The Chinese tourism research shows that the smaller the spatial scale, the higher the frequency of keywords, and the larger the spatial scale, the fewer the keywords. This is the opposite to the conclusion of Yu et al. [48], who believe that most of the Chinese research has been dedicated to large areas, possibly because they only counted the high-frequency keyword "China" and did not study low-frequency keywords. The international tourism researchers identify the country of interest.
In the research target, there are some common keywords in the Chinese and international research, such as hotels, residents, stakeholders, communities, tourists, hotel industry, destinations, etc. Of course, there are also some keywords with high attention in China but low attention in the international community, and keywords with high attention in the international community but low attention in Chinese scholars. The Chinese tourism researchers have been comparatively more interested in tourism enterprises, governments, and inbound tourists. International researchers have paid more attention to more types of tourists, including backpackers and Chinese tourists (as potential visitors), confirming the research of Zhang et al. [93]. With respect to the tourism industry, the Chinese tourism research concerns the cruise industry, the exhibition industry, etc., while the international tourism research focuses on the hospitality industry, local tourism, and agricultural tourism. In terms of tourism attractions, homestays and cruise ships have attracted the attention of the Chinese academia and international scholars had more research on national parks, world cultural heritage sites, and festivals. With respect to the tourism activities, heritage tourism, black tourism, urban tourism, and cruise tourism have received high attention in the Chinese and international research, which is basically consistent with the conclusion of Yu et al. [48]. Red tourism, mass tourism, and all-for-one tourism as unique tourism forms in China have received high attention from the Chinese research, while international attention has also been paid to wildlife tourism, community tourism, and medical tourism. The differences between the Chinese and international tourism research target are closely related to the development of tourism. At present, the Chinese tourism industry is in an important stage of transformation and upgrading to high-end and high-quality, and business tourism and medical tourism have not been popularized, thus the Chinese tourism research has relatively less research on such tourism industry and tourism activity. The Chinese tourism research is largely led by the role of government policies. In recent years, under the guidance of the government's rural revitalization strategy, rural tourism has become a hot issue in the Chinese tourism research.
In terms of research methods, quantitative methods are widely used in the Chinese tourism research, which is consistent with the research conclusions of Wang et al. [49]. He found that quantitative research methods were the mainstream of the Chinese tourism research applications from 2006 to 2016. The application of quantitative methods in the Chinese tourism research has gradually matured, and the combination of qualitative and quantitative methods has also become an important trend in the application of the Chinese tourism research methods [49]. However, the international tourism research has earlier paid attention to the lack of depth of theoretical thinking in quantitative research methods, focusing more on qualitative research methods and multidisciplinary methods, emphasizing the importance of combining qualitative and quantitative methods for problem research. There is still a certain gap between the Chinese and international tourism research in this aspect. The comparison of research methods can be seen that the theory and methods of the Chinese tourism research followed the pace of the international tourism research.
From the perspective of research disciplines, the fields that Chinese scholars pay less attention to have relatively high international attention, and the fields that Chinese scholars pay more attention to have relatively low international attention. Tourism marketing and business management are the disciplines that both the Chinese and international tourism academia pay more attention to, with the most abundant research topics and content. Tourism sociology and tourism anthropology, tourism geography and tourism planning and development, tourism marketing and business administration, tourism ecology and sustainable development are more valued in the international tourism research than in the Chinese tourism research. In contrast, tourism psychology and tourist behavior, tourism research and tourism education, tourism public administration and tourism politics, and tourism economics received more attention in the Chinese tourism research. Compared with the research conclusions of Dong et al. [50], this reflects the obvious increase in the research of tourism public administration, tourism politics, and tourism economics in the past ten years, which confirms Yang et al.'s [92] belief that tourism economics has received increasing attention from Chinese scholars in recent years.
The research of tourism economics, tourism ecology, and sustainable development is scarce in both the Chinese and international tourism research, with little content and few topics. However, the international research on ecotourism and sustainable development has a high degree of attention, and the research is very in-depth, with core keywords or themes. Sustainability is a topic that has been increasingly considered and studied by the tourism discipline [94]. Although Yu et al. [48] and Lian et al. [63] found that "ecotourism" has received a lot of attention in the Chinese tourism research, the depth of the Chinese tourism research is not as great as that of the international research.
The reasons for these differences, on the one hand, are caused by the different development stages of the Chinese and international tourism industry and tourism research. The international tourism industry and tourism research developed early, and the research in some fields is relatively mature, e.g., in tourism psychology and tourism behavior. On the other hand, it is also related to the Chinese tourism education system. The discipline of tourism is combined with the discipline of management in China. On the whole, the Chinese tourism research is mainly undertaken by university scholars with tourism management majors. Therefore, the research discipline orientation is limited to the fields of management and geography [81]. In addition, the differences in the academic research habits, academic norms, and cultures in China and internally also contribute to the differences in the content of the Chinese and international tourism research.
In terms of the timeline map and bursts, there is a big difference in the research progress and hot trends between the Chinese and international tourism research. The keywords of the Chinese tourism research show Chinese characteristics; meanwhile, they also reflect the trend of following the hotspots of the international tourism research. For example, the international tourism research focused on "destination image" in 2012, then in 2014, the focus on "destination image" increased in the Chinese tourism research. As Xie [7] said, the Chinese tourism research showed a trend of following international hotspots. The Chinese tourism research focused on research progress and literature review in 2015-2018, which reflects the Chinese scholars' attention to previous Chinese and international tourism research. The international tourism research has a greater focus on "sharing economy", "ecotourism", "social media", and "tourist experience".

Research Prospect
This research tried to bridge the Western and Chinese academic literature on tourism journals. The Chinese and international tourism research has brought the Chinese-language tourism literature to the global audience [67]. There are some common research focuses and hotspots in the Chinese and international tourism research. In some research fields, there are still obvious differences in the content, methods, and depth of the Chinese and international tourism research. The Chinese tourism research is largely guided by government policies, and research issues are closely related to national policies and guidelines. In terms of research methods, Chinese scholars follow the international pace and trend and tend to combine qualitative and quantitative research methods. With respect to the research area, domestic regions are of interest. With respect to the research subject, there is much related research on tourism marketing and business administration, tourism public administration and tourism politics, tourism sociology and tourism anthropology, while research on tourism economics, tourism ecology and sustainable development is scarce. In the international tourism research, the research issues have a more global perspective, and the significant issues such as ethnicity and human beings are discussed in depth. With respect to the research methods, the application of qualitative methods in the international tourism research has been relatively mature. With respect to the research area, the international tourism research involves all countries and regions in the world, of which the research of countries as the research object is the most prevalent. With respect to the research subject, there is more research on tourism marketing and business administration, and less research on tourism research and tourism education and tourism economics. The international tourism research has a high degree of in-depth studies on tourism ecology and sustainable development and pays much attention to the theme of "sustainable tourism development".
Through the comparison of the Chinese and international tourism research, the following aspects are proposed for the future development of the Chinese tourism research: Firstly, in terms of research issues and themes, we should continue to highlight the Chinese characteristics and the characteristics of the Chinese tourism development. Meanwhile, we suggest that the hotspots of the international academic discussion should be identified, closely following the international trends. Secondly, in terms of research methods, the application of qualitative methods should be strengthened, and international tourism theories should be introduced and absorbed to enhance the theoretical height of the Chinese tourism research. In addition, in the context of the Chinese ecological civilization strategy, it is necessary to further strengthen the attention to and research on tourism ecology and sustainable development.
This study also has limitations. The selection of journals may affect the research results due to the different focus and research fields of each journal. In addition, only four journals were selected as research objects, which cannot fully represent the whole of the Chinese and international tourism research. In the future, more journal articles should be added for tourism-knowledge domain research.

Data Availability Statement:
No new data were created or analyzed in this study. Data sharing is not applicable to this article.

Conflicts of Interest:
The authors declare no conflict of interest.