The Relative Importance of Volunteer Tourism (Sustainable/Pro ‐ Social Form of Tourism) Motivation Factors for Young Tourists: A Descriptive Analysis by Continents, Gender, and Frequency

: Volunteer tourism is a vital formation of altruistic and sustainable tourism. This research is aimed to empirically find the relative importance of the motivation factors and the motivation realization factors for young tourists participating in the global volunteer tourism programs. The differences in the study variables across continents, gender, and frequency of participation were also scrutinized. A quantitative research approach that utilized the survey method was employed. The outcomes showed that personal development was the most vital motivator for global volunteer tourism. On the other hand, the young tourists felt that they most realized the factor of a new experience through their recent international volunteer tourism experience. The motivation factors and the motivation realization factors were consistent across the continents. Furthermore, the mean differences in the motivations, the motivations’ realization, satisfaction, and the behavioral intentions were revealed to be non ‐ significant for the genders and the frequency of volunteer participation. By grasping the young volunteer tourists’ motivations and the experience evaluations, the volunteer programs can be advanced in consonance with their necessities and demands, which enhance the volunteer tourism experience.


Introduction
Volunteer tourism is known as social work where the travelers combine leisure travel with voluntary work [1]. In other words, it is a type of tourism where a tourist not only enjoys tourism but also offers his/her time to volunteering. In that sense, volunteer tourism is different from other forms of sustainable tourism, in which these volunteer tourists develop themselves in addition to gaining meaningful experiences and learning from it [1,2]. Sustainable tourism is a concept that introduces sustainable development into tourism, and it is to develop or use tourism resources at a level that meets the needs of the current generation without compromising the conditions required by the next generation [3]. The principles of sustainable tourism refer to the pursuit of environmental, economic, and sociocultural sustainability, and only when these three principles are in harmony will have long-term sustainability [3,4]. It is a variation of tourism products, which is commonly characterized as community-centered. In addition to intrinsic benefits, which include self-development, volunteer tourists are dedicated to ameliorating social, ecological, and cultural conditions within the host communities [2,[5][6][7]. In response to the rising interest in volunteer tourism among tourists in different areas of the world, the growth in the delivery of the volunteer tourism opportunities from various stakeholders, which include the destination marketing organizations, the non-profit organizations, and the tour operators, has been substantial [8,9]. In past decades, the focus of volunteer tourism has been international, including China [10], the Philippines [11], Ghana [12], India [13], Rwanda [7], and Thailand [14]. This growth is indicative of the prevalent intentions among the travelers to connect leisure travel with a tangible contribution to societal wellbeing and/or environmental restoration [15].
The upsurges in the volunteer tourism chances have been coincided with an increase of tourism literature that focuses on the internal and the external behavior of volunteer tourists [16][17][18][19][20]. While the existing studies have accentuated why people seek international volunteer experiences [10,13,21,22], there has not been as many attempts to statistically examine the young tourists' responses to volunteer tourism and how they may vary across market segments. Tourist motivations are complicated particularly for international volunteers, because the motivations can be different across individual backgrounds [23]. It has been argued that the individuals who get the most benefits from volunteer tourism seem to be certain types of volunteers [16]. The past volunteer tourism studies, which predominantly utilized a qualitative and exploratory research approach, have demonstrated a variety of motivations depending on the trip and the demographics characteristics, such as the program duration, the program orientation, age, gender, education, and the level of experience of volunteering [10,16,[24][25][26][27]. This implies that the program-related factors, the individual peculiarities, and the certain circumstance factors/relationship are related to the people inspirations to engage in volunteer tourism. Yet, the profiles of the young volunteer travelers are not fully explored [23,28], so they therefore deserve continuing attention in tourism literature.
Thus, it is important that volunteer organizers gain a concrete understanding of the volunteers that participate in the international volunteer programs. Motivations represent the reasons why tourists choose volunteer tourism. The motivation realization means what kind of motivation had been realized, through volunteer tourism. Volunteer tourism motivations can commonly be grouped into three factors; personal, interpersonal, and context-specific [10]. Firstly, personal motivation is said to satisfy intellectual curiosity, learn academic/cultural knowledge, increase self-confidence, and stimulate self-development to grow oneself. This can also include the motivation for relaxation, stress relief, and away from congested and repetitive daily life [29][30][31]. Motivation related to interpersonal includes those who want to help someone, do constructive work, improve the host communities, and have cross-cultural exchange and friendship [32][33][34]. Finally, context-specific motivations include participation that driven by a project mission and location [35][36].
Gaining a better understanding of the relative weights of the motivation factors and motivation realization factors by continents, identifying how the volunteer tourists participate across gender, and evaluating the volunteers' level of experience can be beneficial to the organizers in order to accommodate the tourists' necessities and demands and to found successful marketing tactics. By knowing the volunteer tourist motivations and how they may differ across the segments, the organizers can create volunteer programs and activities in line with these motivations, which can lead to enhanced the volunteer tourism experiences and subsequently affect the volunteers' intention to participate in the future volunteer programs [20]. In addition, customer satisfaction and the behavioral intentions may differ based on the personal characteristics and the situation-specific characteristics [37][38][39][40][41]. Understanding the differences in satisfaction and the behavioral intention between the market segments can be a good foundation for volunteer tourist segmentation. The planning and organizing of volunteer tourism work best when the organizers comprehend the demand of volunteer tourism from the point of view of the volunteers or the travelers [42]. To entice the potential volunteers into volunteer tourism, one must understand why the existing volunteers participate in volunteer tourism, how they evaluate their actual volunteer experience, and how the evaluation varies by the market segments.
Consequently, the present study aimed to perform the following research objectives using a descriptive analysis and a mean-difference test.  Our first research objective is to rank the motivation factors for international volunteer tourism, which included (a) personal value/belief, (b) contribution to the host community, (c) societal contribution, (d) personality/attitude improvement, (e) personal development, (f) new experience, (g) different culture/customs, (h) language learning/practice, (i) better job opportunity, (j) escape from repetitive routines, and (k) avoidance of reality.  Our second research objective is to rank the motivation realization factors through volunteer tourism, which included (a) personal value/belief, (b) contribution to the host community, (c) societal contribution, (d) personality/attitude improvement, (e) personal development, (f) new experience, (g) different culture/customs, (h) language learning/practice, (i) better job opportunity, (j) escape from repetitive routines, and (k) avoidance of reality.  Our third goal is to discover the relative importance of the volunteer tourism motivations by the continents, which included (a) Asia, (b) Africa, (c) America, and (d) Europe and Australia.  Our fourth goal is to discover the relative importance of the volunteer tourism motivation realization factors by the continents, which included (a) Asia, (b) Africa, (c) America, and (d) Europe and Australia.


Our fifth research goal is to identify if a gender difference exists with the volunteer tourism motivations, the volunteer tourism motivation realization, satisfaction with the volunteer tourism experiences, and the behavioral intentions for volunteer tourism.  Lastly, our sixth research objective is to uncover a possible difference that exists with the volunteer tourism motivations, the volunteer tourism motivation realization, , satisfaction with the volunteer tourism experiences, and the behavioral intentions for volunteer tourism across the first-time volunteer tourists and the repeat volunteer tourists.

Motivations and Realization of Volunteer Tourism
International volunteer tourism enhances the individuals' cross-cultural understanding and the value of life, and it builds up the tolerance of life [5,[43][44][45]. Volunteer tourism is thus growing in popularity in the tourism literature as one critical type of altruistic/sustainable tourism [43,[46][47][48]. Volunteer tourism also minimizes the possible negative impacts of the tourism industry without damaging a host community [43,49]. Meng et al. [45] insisted that one of the important motivations of global volunteer tourism is to fulfill themselves. Indeed, they found that the key motive for joining volunteer tourism is to change one's personal life and improve his/her personal growth. This reason can be one of the important facets of volunteer tourism motivations [5,[46][47][48].
According to Han et al. [44], the concept of the volunteer tourism motivation has a multidimensional nature. They indicated that the volunteer tourism motivation is a significant driver for the volunteer travelers to seek for the chances and commit themselves to help other people and sustain their involvement in volunteer activities. Diverse factors can be the constituents of the volunteer tourism motivations [43,44,47,48]. The components are personal value/belief, contribution to the host community, societal contribution, personality/attitude improvement, personal development, new experience, different culture/customs, language learning/practice, better job opportunity, escape from repetitive routines, and avoidance of reality [43][44][45]48,50]. The realization of volunteer tourism motivation refers to the attachment of such motivation factors [45,48]. Han et al. [44] indicated that individuals attain altruistic goals, self-enhancements, social adjustments, personal developments, and novelty experiences through the motivation realization of volunteer tourism. In this regard, international volunteer tourism appeals to travelers in diverse races in various continents/cultures, different genders, and different tourism experiences [43,45,47,48,50].

Tourist Behaviors in Different Continents/Cultures
Culture is widely recognized to affect the international tourists' intention generation process and purchase behaviors [51][52][53]. Many researchers in the tourism sector agree that a considerable difference with international tourists' motivation, satisfaction evaluations, and behavioral intentions is derived from the cross-cultural disparity [51,52,[54][55][56]. The traveler decision-making process and the behaviors also differ by the continents [43]. The present research centered on four continent-groups, which include (a) Asia, (b) Africa, (c) America, and (d) Europe and Australia, Antarctica barely has any permanent human inhabitants, so it wasn't included in the study. Also, Europe and Australia have similar cultures, so they were grouped together [57,58]. The potential dissimilarity by continents/cultures is increasingly becoming crucial in the international destination practitioners to develop new destination attributes, enhancing destination quality, increasing loyalty for the destination, and boost the visitor retention rate [51,53,55].

Satisfaction with Volunteer Tourism Experiences
Traveler satisfaction is a fundamental concept in the tourism literature [59,60]. Satisfaction in conjunction with motivations is considered as two major factors that influence the individuals' decision-making process and consumption conduct in hospitality and tourism [60][61][62][63]. According to Rychalski and Hudson [64] and Han and Hyun [60], ensuring satisfaction and boosting customer retention are the essential requisites for a company's profit increase and financial success. Satisfaction indicates tourists' judgment whether a specific tourism product and its attributes provide an enjoyable/acceptable level of fulfillment when consuming the product [65]. The key feature of satisfaction is the assessment procedure [60,61,66]. When travelers satisfactorily experience a tourism product/destination, it is likely that they build positive behavioral intentions for the product/destination [49]. Indisputably, satisfaction is also a core concept for eliciting travelers' favorable decision-making process and conduct regarding volunteer tourism [44].

Behavioral Intentions for Volunteer Tourism
Dealing with the tourists' behavioral intentions in an efficient manner is an essential process for the long-term success of every hospitality/tourism firm and destination [45,65,[67][68][69]. When tourists' purchase/post-purchase intentions for a place/product are high, they show a willingness to repeatedly visit the place or re-buy the product, and they encourage others to visit the place or purchase the company's product [18,70,71]. Hence, enhancing the travelers' positive behavioral intentions for the destination/firm has long been a significant issue among destination/tourism marketers and researchers. Oliver [65] conceptualized behavioral intentions as the tourists' affirmed likelihood to conduct a certain tourism/consumption behavior. According to Jeaheng et al. [68] and Bowen and Shoemaker [70], the tourists' readiness/willingness to buy a tourism product, use a hospitality service, and recommend it are 8the major facets of the behavioral intention assessment. Based on this, behavioral intentions in the present study refer to the tourists' affirmed likelihood of participating in a global volunteer tourism course, continuing with volunteer tourism activities, and recommend it to others.

Gender Differences
Gender in tourism has always been regarded as one of the most vital socio-demographic variables affecting an individual's diverse travel decision-making process/behaviors [40,72,73]. The recent researches in the hospitality and tourism sectors provide evidence regarding gender differences in the formation of the tourists' behavioral intentions [40,[71][72][73][74][75]. In these studies, it is quite conclusive that the travelers purchase behaviors differ across genders. The findings of these studies are also in line with a social role theory that difference in gender act a dissimilar role in the community, because they have been socialized in a distinctive way [76]. Therefore, comprehending the dissimilarity across male tourists and female tourists is regarded as a critical requisite to invent efficient marketing and retention tactics for every tourism destination practitioner, which includes volunteer tourism [40,[73][74][75].

The First-Time Volunteer Tourists' vs the repeat Volunteer Tourists'
Some researches in the present tourism literature indicate that the individuals' previous tourism experiences serve as an essential source of information in one's decision development [77,78]. These types of existing tourism experiences affect the individuals' tour planning [77,79]. According Chua et al. [77], the first-time volunteer travelers and the repeat volunteer travelers are dissimilar in diverse aspects when making a travel decision and engaging in a tourism behavior. The difference between the two traveler segments is from product-related knowledge, comfort, information, and confidence, which can result in dissimilar before-travel planning and after-travel appraisal [39,77,[79][80][81]. Comprehending the dissimilarity in the travelers' decision formation and the behavior between the volunteer travelers, who firstly participate vs. repeatedly participate, is crucial to provide a strong basis for the market segmentation and for the service strategy [39,81]. Yet, empirical comparisons about the disparity across the first-time volunteer tourists and the repeat volunteer tourists regarding the overseas volunteer tourists' decision-making process and the behavior are rare in the academic literature. Uncovering the differences between these volunteer traveler segments is therefore of importance in the altruistic tourism sector.

Measures and Development of Survey Instrument
We employed the measurement items from the current literature in volunteer tourism and consumer behavior. A multiple-item scale and a 7-point scale were used to estimate all the study constructs. Explicitly, the eleven measurement items, which included (a) personal value/belief, (b) contribution to the host community, (c) societal contribution, (d) personality/attitude improvement, (e) personal development, (f) new experience, (g) different culture/customs, (h) language learning/practice, (i) better job opportunity, (j) escape from repetitive routines, and (k) avoidance of reality, were used for volunteer tourism motivations. In addition, the corresponding 11 items for the realization of motivations were used. The items were adopted from Han et al. [44], Meng et al. [45], and Lee et al. [48]. The satisfaction with volunteer tourism motivation was evaluated by 3 items. These items were employed from Oliver [65]. To measure the behavioral intentions for volunteer tourism, 4 measurement items were utilized, which were adopted from Ajzen [82] and Oliver [65]. The survey instrument includes aforementioned measurement items, study purpose, and inquiries for personal characteristics. In addition, it was reviewed and perfected by tourism academics whose key research area is volunteer/altruistic tourism. The details of all measurement items are presented in the Appendix A.

Data Collection and the Samples
The survey was conducted using a convenience sampling technique. We contacted a non-profit volunteer tourism organization. The organization has run an overseas volunteer program since 2008. A total of 9271 volunteers have been participating from 95 different countries. The organization has one of the biggest overseas volunteer programs in the world. In 2018, about 450 university students joined the festival held by the volunteer tourism organization. The core of the festival is the volunteer tourism participant's homecoming party that helps to celebrate their achievements throughout their overseas volunteer work. Our survey took place during the homecoming festival.
The sample of this survey was volunteer travelers who participated in overseas volunteer programs through the organization for 10 months, which was from end of January 2018 to beginning of December 2018. The research investigators precisely explained about the purpose of this study before distributing the questionnaire and advised that all responses remained confidential and anonymous. The surveyors also helped the volunteer travelers request the survey participants to recall their previous experience before starting the survey. All survey participation was done in a voluntary manner. The participants completed the questionnaire and returned it onsite. A USB flash drive with the organization's logo was provided as an expression of gratitude. Through this process, in total 330 answered questionnaires among 400 distributions were returned. Of the 330 respondents, 47.3 % (n = 156) were males and 52.7% (n = 174) were females. The average age was 23.7 years old. A majority of the participants (about 93.4%) were university students. Among the participants, about 269 (81.5%) respondents described that it was their first time taking part in a volunteer tourism course. In addition, about 40 (12%) respondents reported that it was their second time, and about 21 (6.3%) respondents indicated three or more times.

Comparative Importance of the Volunteer Tourism Motivation Factors
The order of importance among the volunteer tourism motivations was examined. SPSS 20 for Windows was used as a tool for the descriptive analysis. As noted in Table 1, (1) indicates the most important motivation for global volunteer tourism, and (11) indicates the least important motivation for global volunteer tourism. The table shows that personal development (mean = 6.29) was the most important international volunteer tourism motivation factor, which was followed by language learning/practice (mean = 6.05), personality/attitude improvement (mean = 5.97), escape from repetitive routines (mean = 5.87), different culture/customs (mean = 5.65), new experience (mean = 5.60), personal value/belief (mean = 5.48), contribution to the host community (mean = 4.99), better job opportunity (mean = 4.58), societal contribution (mean = 4.51), and avoidance of reality" (mean = 4.39). This result implies that when individuals make a decision regarding global volunteer tourism, personal development is the most critical motivator, learning language/practice is the second most important motivator, and personality/attitude improvement is the third most important motivator. These findings contributed to obtaining the first objective of this research.

Examination of the Motivation Realization Factors through Volunteer Tourism
The order of criticality among motivation realization through volunteer tourism was investigated by using a descriptive approach. The details are exhibited in Table 2. As shown in Table  2, (1) indicates the most critical motivation realization factor, and (11) indicates the least critical motivation realization factor with respect to international volunteer tourism. In particular, a new experience (mean = 6.52) was identified as the most important motivation realization, followed by personal development (mean = 6.28), different culture/customs (mean = 6.27), language learning/practice (mean = 6.21), escape from repetitive routines (mean = 6.05), personality/attitude improvement (mean = 6.01), contribution to the host community (mean = 5.85), personal value/belief (mean = 5.83), better job opportunity (mean = 5.74), societal contribution (mean = 5.51), and avoidance of reality (mean = 5.42). This finding implies that individuals feel that they most effectively realized the motivation of a new experience through their recent international volunteer tourism experience. Meanwhile, this finding implies that individuals feel that they least effectively realized the motivation of societal contribution through their recent volunteer tourism experience. These results contributed to achieving the second research objective. Table 2. VT motivation realization -overall ranking by mean. (1). New experience (M = 6.52 and SD = .84) (2). Personal development (M = 6.28 and, SD = .95)

Relative Importance of Volunteer Tourism Motivation Factors by Continents
The relative importance of volunteer tourism motivation factors by continents, which include (a) Asia, (b) Africa, (c) America, and (d) Europe and Australia, were examined with the use of a descriptive analysis. The details about the descriptive analysis results are shown though Figure 1 to Figure 4. First, the order of criticality among the eleven motivation factors in Asia was examined. The eleven factors are the important motivators of volunteer tourism for countries in Asia. Figure 1 shows that personal development (mean = 6.21) was the most important motivator, which was followed by language learning/practice (mean = 6.11), personality/attitude improvement (mean = 6.02),  Second, the order of importance among the motivation components for volunteer tourism in Africa was investigated. Figure 2 shows that personal development (mean = 6.16) was the most critical motivator, which was followed by personality/attitude improvement (mean = 5.99), language learning/practice (mean = 5.94), escape from repetitive routines (mean = 5.70), different culture/customs (mean = 5.66), personal value/belief (mean = 5.62), new experience (mean = 5.55), contribution to the host community (mean = 5.20), better job opportunity (mean = 4.43), societal contribution (mean = 4.37), and avoidance of reality (mean = 4.15). Among the volunteer tourism motivation factors, personal development most efficiently motivates the volunteer tourists to travel to countries in Africa, and the avoidance of reality efficiently motivates them the least to travel to travel to countries in Africa, which is similar to volunteer tourism motivations in Asia. Third, the relative criticality among the volunteer tourism motivation components in America was examined. As reported in Figure 3, our result revealed that personal development" (mean = 6.32) was the most important motivator of volunteer tourism to countries in America, which was followed by language learning/practice (mean = 6.03), escape from repetitive routines (mean = 5.97), personality/attitude improvement (mean = 5.89), different culture/customs (mean = 5.67), new experience (mean = 5.66), personal value/belief (mean = 5.33), contribution to the host community (mean = 4.90), avoidance of reality (mean = 4.61), better job opportunity(mean = 4.60), and societal contribution (mean = 4.55). Among the volunteer tourism motivation factors, personal development was identified as the most efficient motivator of volunteer tourism to countries in America, but the least importance volunteer tourism motivation factor in America was societal contribution, which is similar to volunteer tourism motivations in Asia and Africa. Fourth, the order of criticality among the volunteer tourism motivation factors in Europe and Australia were examined. As reported in Figure 4, our results indicated that personal development (mean = 6.55) was the most important motivator, which was followed by language learning/practice (mean = 6.18), personality/attitude improvement (mean = 6.02), escape from repetitive routines (mean = 6.00), new experience (mean = 5.71), different culture/customs (mean = 5.53), personal value/belief (mean = 5.44), contribution to the host community (mean = 4.87), better job opportunity (mean = 4.77), societal contribution (mean = 4.71), and avoidance of reality"(mean = 4.55). Among the volunteer tourism motivation factors, personal development most effectively motivates the volunteer tourists to travel to countries in Europe and Australia, and the avoidance of reality was the factor that effectively motivates them the least to travel to countries in Europe and Australia. Overall, this result contributed to obtaining the third objective of the present research.

Volunteer Tourism Motivation Realization Factors by Continents
The relative importance of the volunteer tourism motivation realization factors by continents, which include (a) Asia, (b) Africa, (c) America, and (d) Europe and Australia, was investigated by using a descriptive analysis. The outcomes are exhibited though Figure 5 to Figure 8. First, the order of importance among the eleven motivation realization components in Asia was investigated. As reported in Figure 5, our result showed that a new experience (mean = 6.51) was the most important motivation realization factor, which was followed by different culture/customs (mean = 5.23), language learning/practice (mean = 6.23), personal development (mean = 6.23), escape from repetitive routines (mean = 6.05), personality/attitude improvement (mean = 6.00), contribution to the host community (mean = 5.77), "personal value/belief" (mean = 5.74), "better job opportunity" (mean = 5.70), avoidance of reality (mean = 5.54), and societal contribution (mean = 5.38). This finding implies that individuals feel that they most effectively realized the motivation of a new experience through their volunteer tourism experience in a country in Asia, but they feel that they least efficiently realized the motivation of societal contribution through their volunteer tourism experience.  Second, the relative criticality among the motivation realization factors in Africa was examined. As exhibited in Figure 6, our findings indicated that a new experience (mean = 6.55) was the most critical motivation realization factor, which was followed by different culture/customs (mean = 6.41), personal development (mean = 6.40), language learning/practice (mean = 6.27), personality/attitude improvement (mean = 6.16), personal value/belief (mean = 6.13), escape from repetitive routines (mean = 6.09), contribution to the host community (mean = 6.01), better job opportunity (mean = 5.83), societal contribution (mean = 5.71), and avoidance of reality (mean = 5.64). This finding implies that travelers feel that they most efficiently realized the motivation of a new experience through their volunteer tourism experience in a country in Africa, which is similar to the result from the countries in Asia. Third, the comparative importance among the motivation realization constituents in America was investigated. As Figure 7 displays, our results discovered that a new experience (mean = 6.54) was the most important motivation realization factor, which was followed by language learning/practice (mean = 6.35), different culture/customs (mean = 6.27), personal development (mean = 6.25), escape from repetitive routines (mean = 6.04), personality/attitude improvement (mean = 5.93), personal value/belief (mean = 5.75), better job opportunity (mean = 5.70), contribution to the host community (mean = 5.68), societal contribution (mean = 5.48), and avoidance of reality (mean = 5.38). This result implies that individuals feel that they most effectively realized the motivation of a new experience through their volunteer tourism experience in a country in America, but they feel that they least effectively realized the motivation of avoidance of reality through their volunteer tourism experience, which is similar to the finding from the countries in Asia and Africa. Fourth, the relative criticality of the motivation realization components in Europe and Australia were examined as shown in Figure 8. As reported in Figure 5, Figure 6, and Figure 7, our findings showed that new experience (mean = 6.40) was the most critical motivation realization constituent, which was followed by personal development (mean = 6.21), different culture/customs (mean = 6.13), escape from repetitive routines (mean = 6.05), personality/attitude improvement (mean = 5.92), contribution to the host community" (mean = 5.90), language learning/practice (mean = 5.85), better job opportunity (mean = 5.66), "personal value/belief" (mean = 5.58), "societal contribution" (mean = 5.40), and avoidance of reality (mean = 5.02). Our findings implies that the travelers feel that they most efficiently realized the motivation of new experience through their volunteer tourism experience in a country in Europe/Australia, which is consistent with the result from the countries in Asia, Africa, and America. Overall, this result contributed to achieving our fourth research objective.

Gender Difference on Volunteer Tourism Motivation, Motivation Realization, Satisfaction and Intentions
The gender difference was tested on the study variables. As Table 3 displays, the female group (mean = 5.41) had a higher score than the male group (mean = 5.39) for the volunteer tourism motivations. The mean score for the motivation realization was also higher for the female group (mean = 5.98) than the male (mean = 5.97). In addition, the male group (mean = 6.16) had a higher score for satisfaction with the volunteer tourism experiences than the female (mean = 6.01). Moreover, the mean score for the behavioral intentions was higher for the female group (mean = 5.77) than the male (mean = 5.66). However, the outcomes of the analysis of variance (ANOVA) tests revealed that there are no significant differences on the volunteer tourism motivations (F  Table 3 includes the details pertinent to the ANOVA outcomes. Overall, because there were no significant mean differences on the study variables, our fifth research objective was achieved.   Table 4 presents the difference of the volunteer tourism frequency, which includes the first-time volunteer travelers and the repeat volunteer travelers, and which was tested on research variables. The mean score for the volunteer tourism motivations was higher for the repeat volunteer travelers (mean = 5.53) than in the first-time volunteer travelers (mean = 5.37), whereas the mean score for motivation realization was higher for the first-time volunteer travelers (mean = 5.94) than the repeat volunteer travelers (mean = 5.12). In addition, the repeat volunteer travelers (mean = 6.12) had a higher mean score for satisfaction with the volunteer tourism experiences than the first-time volunteer travelers (mean = 6.07). The mean score for the behavioral intentions was also higher in the repeat volunteer travelers (mean = 5.88) than in the first-time volunteer travelers (mean = 5.68). Nonetheless, our results from the ANOVA tests discovered that there is no significant difference among the volunteer tourism motivations (F [1,328] Table 4 includes the details about the ANOVA results. In sum, because there were no significant mean differences that existed on the study constructs, our sixth research objective was obtained.

Discussion and Implication
The current study ranked the importance of both the motivations and the motivation realization factors of volunteer tourism, which identified the relative importance of these two motivations by the continents, and they examined the gender differences and the frequency differences on the motivations, the motivation realization, satisfaction, and the behavioral intentions. Chained descriptive analysis and ANOVA assessments were used. Overall, the results of this study provided a better understanding of the critical constructs of the volunteer tourism programs, and some proper strategies to promote volunteer tourism should be included. In particular, the volunteer tourism program managers should always know that most tourists participated in volunteer tourism to develop themselves, which was followed by the motivation of experiencing new things. The least important motivation may be contributing to the local community. However, through volunteer tourism experience, tourists changed their mind a little bit by ranking the meeting new as the most important motivation realization. The descriptive analysis by the different continents demonstrated that the tourists have very similar motivations and motivation realizations despite the different volunteer tourism destinations. Although there are many prior studies exploring why people look for international volunteering experiences [10,13,21,22], there are few statistical examinations of young tourists' response to volunteer tourism and how they differ depending on market segments. From a theoretical perspective, our study clarifies the motivation on volunteer tourism, which has not been previously studied often. Hence, this research would offer a broad picture regarding the relative importance of volunteer tourism motivations across market segments. From a practical perspective, the study results elucidate a management of the volunteer tourism programs as well as present a better design for the volunteer tourism activities. For example, it will help in the direction of development of volunteer tourism products, such as which programs/activities best reflect the motivations of volunteer tourists and realize motivational factors, and how well the programs/activities are delivered to participants. The specific implications of the current study are summarized as follows.
First, motivations represent the reasons why tourists choose volunteer tourism. The outcomes of the comparative importance of the volunteer tourism motivation indicated that some personal factors, which included personal development and language learning/practice, ranked as the most important reasons for choosing international volunteer tourism programs, while some factors related to environment, which included escape from repetitive routines and different cultures, were next. In addition, the factors that related to some volunteer reasons, such as the contributions to the host communities and the societal contributions ranked as at the end. Thus, to promote volunteer tourism programs, the managers should understand that personal factors should be strengthened first. Advertisement slogans, such as Discover a New Self or Amazing Culture may be better than Help the Local.
Second, the motivation realization means what kind of motivation had been realized, through volunteer tourism. The current study results revealed that some environment factors, which include new experiences and different cultures/customs, ranked as the most important realization motivations, which was followed by personal factors, which include language learning and personality/attitude improvements, and volunteer factors, such as contributions to the host communities and societal contributions. Thus, the volunteer tourism programs should provide volunteer tourism activities that can fulfill their personal factors. For instance, personalized and memorable volunteer tourism activities should be well designed to provide new experiences. In order to provide culture/customs, interactive contacts between the travelers and the whole community be focused. To sum up, the volunteer tourism tourists weigh heavily on some personal factors rather than the environment factors as their motivations. However, tourists believe that the environmental factors were the more important realization motivations than the personal factors through their experiences in the volunteer tourism programs. As for the volunteer factor, the tourists consider it as the least important factor, which is not a motivation nor a motivation realization.
Third, the relative importance of the motivations and the motivation realization by continents indicated that the different strategies could be developed based on the volunteer tourism destinations. Generally speaking, the three top-ranked motivation factors were personal development, language learning/practice", and personality/attitude improvement. As international volunteer tourism, tourists choose overseas destinations due to the unique challenges they present, which are hard to achieve in their daily lives. The marketers should understand that no matter what country the tourists want to go to, the key benefits that the tourists desire are the same. Rather than introducing the cultural variety and the differences with the different continents, the volunteer tourism managers should stress the benefits of the personal enhancements more as the outcomes from the volunteer tourism. Our results also revealed that the tourists who choose volunteer tourism in America had a different important motivation, which is escape from repetitive routines. The slight difference in America may be that the American culture is familiar to the world, and the tourists may experience less culture shock and less perceptions regarding risk.
Fourth, the study results that are relatively important to motivation realization by continents revealed that the top motivation realization that ranked in the first three places were new experiences, different culture/customs, and personal development among all four continents. Therefore, no matter what continents the tourists chose, they all consider that a new and special experience come before personal development. Therefore, volunteer tourism program managers should know that the key point to design volunteer tourism depends on the uniqueness, excitement, and novelty of an experience for any volunteer tourism destinations. Meanwhile, the avoidance of reality was one of the last motivations among the four different continents recorded as one of the least important factors. Thus, the tourists did not think that escaping reality is a critical factor in a general tourism form no matter what volunteer tourism destination was considered. It seems that the tourists were not escaping reality, but they were facing the reality of their personalities or foreign language skills. Therefore, the marketers should provide some moderate difficulty that can help to form the personal achievement.
Fifth, as indicated in the previous literature, the gender and the frequency should have different demands and requirements regarding the service offered by a service provider [71,83]. In this sense, the visitors with different genders and frequencies, for example, first visitors vs. repeated visitors, different strategies could be developed. However, there are no significant differences by the gender with respect to motivations, motivation realizations, satisfaction with volunteer tourism experiences, and behavioral intentions in this study. The volunteer tourism program managers should understand that strategies should be developed by using other marketing variables rather than genders and frequencies. In addition, there are also no statistical differences between the firstly joining travelers and the repeatedly joining travelers. These types of inconsistent study results reveal that the repeated tourists did not change significantly regarding the motivations and still found that their motivations were realized, and their satisfaction and behavioral intention was not significantly reduced compared to the first time they undertook volunteer tourism. In this sense, the volunteer tourism programs seem very effective and valuable to achieve tourists' motivation, satisfaction, and intentions. Thus, the volunteer tourism program managers should know that the same marketing strategies and tourism activities should be developed to satisfy their initial motivations in order to attract the repeated tourists. Nevertheless, it is interesting to find that among the first-time visitors, the score for the motivation realization was a little higher than the score for the motivations, while among the repeat visitors, the score for the motivation realization was lower than their initial motivations. Although not a significant influence, the strategies could also consider the surprising experiences for the repeat visitors, which could include discount benefits for the repeat visitors.

Limitation and Future research
The current study has several limitations that could be further improved in future studies. The population of this research was limited to the young tourists and their motivations only for the year 2018. Thus, the generalization of the study results should not be beyond the current population. So as to increase generalizability of this study outcome, similar research needs to be conducted with a more representative sample and with other volunteer tourism programs in the future. Moreover, some personal traits (e.g., novelty-seeking and authenticity-seeking) and behaviors (e.g., word-of-mouth behavior) should be studied in the future to reflect various perspectives of volunteer tourism and prove a deeper understanding of volunteer tourism behaviors.

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