Online visit opinions about attractions of the religious heritage: an argumentative approach

Abstract Thousands of people every year travel to visit sites of cultural interests and a wide part of those sites belong to the Christian tradition. Tourism represents, indeed, an opportunity for the Church to announce its message and to promote moral and religious formation. Thanks to Web 2.0, then, travelers can easily share contents and voice their opinions online. The study presented in the article analyzed online travel reviews (OTR) about an attraction of the Christian heritage, with the goal of unveiling the arguments that formed the opinion of visitors. The article aims at giving two types of contribution to the body of knowledge about the relation among Church, communication and culture. On one side, it intends to bring the attention on tourism as a phenomenon, which discloses social and cultural dynamics of our time. On the other side, it gives a methodological contribution, by proposing a method to analyze OTR.


Introduction
In 2012, the UN World Tourism Organization (UNWTO) declared that one billion travellers crossed their national borders in a single year for touristic reasons. Another five to six billion ones were estimated to travel in their own countries every year. More than half of them travelled for leisure reasons and chose destinations in Europe (UNWTO 2012). Tourism represents, in fact, one of the largest economic sectors, as well as an activity shared and loved by most people. In the first 50 years of the 20th century, it grew to become one of the major worldwide industries, with a contribution to the world GDP estimated at 10.2% and forecasts over the next ten years predicting growth rates of 3.9% annually (World Travel & Tourism Council 2017).
The English word 'tourism'attested in English language since 1811comes from the French word 'tour', which used to refer to sport trips. The French word 'tourisme'attested in French language since 1841however, is in its turn a loan of the English word tourism. 'Tour' was also used to indicate a coherent and goal-oriented journey, a meaning that is in line with its technical use in sport: 'tour de France' in cycling, for instance, is not a fortuitous roaming, but a journey in stages toward a final destination. Historically, the Grand Tour was the organized journey that European aristocrat descendants used to do out of their homeland, mainly between the 17th and the 19th century, with educational, cultural and personal development goals (Hibbert 1987). Italy was one of the favorite destinations, because of its Greek and Latin heritage (De Seta 1982). Examining the etymology of 'tourism' deeper, it emerges that the French word 'tour' comes from the French verb 'tourner', which originates from the Latin verb 'tornare' that meant to turn, with regard to the ancient activity of working with the lathe (Turismo 2000). It is important to highlight that 'to turn' implies to go back to the original point of departure becoming somehow different, being modified and better shaped. When leaving for a tourism experience, one aims at reaching a destination that also represents the halfway mark to go back to the departure point. At the beginning of the 19th century, thanks to the overall improvement of life conditions and to the development of transportation and communication means, to go on a tour ceased to be a privilege of aristocrats and became a social trend. Today, we can even speak of a 'mass phenomenon' (Bathia 2002).
Even if it is not driven by cultural or educational reasons, tourism is per se a cultural experience and a self-development opportunity, both in itself and in relation to the destination. If considered per se that is as a planned movement within a time and space setting, tourism is a metaphor for human life: every man is a pilgrima 'homo viator'who walks along a path to reach a final destination. If considered in relation with the destination, tourism constitutes an intense, mostly informal, learning experience, in that it both promotes mutual understanding and reinforces the sense of belonging to a certain cultural tradition. Tourists, in fact, have the chance to encounter new cultures, lifestyles, and human communities with their peculiar customs and story; this encounter allows them to better understand their own identity, and to start pondering on their world views, as well as to reduce distances among people and social classes (Hall 2005). Tourism and sport, indeed, share one same goal that is the development of human person and her well-being through physical activity as well as human encountersthese are, indeed, the Olympic ideals.
Tourism, then, is the time of freedom; freedom from daily obligations and routine and, thanks to this, freedom to spend time for what one loves and cares about. The Pastoral Constitution Gaudium et spes identifies in the possibility to nurture one's spirit the very goal of free time and tourism: 'tourism refines man's character and enriches him with understanding of others, through sports activity which helps to preserve equilibrium of spirit even in the community, and to establish fraternal relations among men of all conditions, nations and races' (n. 61). The meaning people give to tourism may differ, being for some a time for escaping the daily routine, for others a time for improving knowledge; though, common to everyone is the experience of an extraordinary time, in the etymological sense of breaking the ordinary time. Even the Bible comments on the extraordinary character of travelling experiences, noticing that it is a trait of the wise man to recognize in the extraordinary time an opportunity to change the quality of ordinary time: A much travelled man knows many things, and a man of great experience will talk sound sense. Someone who has never had his trials knows little; but the travelled man is master of every situation. I have seen many things on my travels, I have understood more than I can put into words. (Sirach 34,(9)(10)(11) Tourists in particular, and people on the move in general, have special spiritual and pastoral needs due to the special circumstances they live in. Despite such circumstances might be very hard for somethat is for those, who did not choose to leave their home place but were forced to do so, like migrants or exiles -, they also represent development opportunities. Well aware of this, on 19 March 1970, with the Motu Proprio Apostolicae Caritatis, Pope Paul VI established the Pontificia Commissio de Spirituali Migratorum atque Itinerantium Cura [Pontifical Commission for the spiritual care of migrants and itinerant people], 'with the task of studying and providing pastoral care to "people on the move" such as: migrants, exiles, refugees, displaced people, fishermen and seafarers, air travelers, road transport workers, nomads, circus people, fairground workers, pilgrims and tourists, as well as those categories of people who, for various reasons, are involved in human mobility, such as students abroad, and operators and technicians engaged in large projects or scientific research at the international level who are obliged to move from one country to another.' 1 The Pontifical Commission was dependent on the Congregation of Bishops until 28 June 1988, when with the Apostolic Constitution Pastor Bonus, Pope John Paul II elevated it to the rank of a Pontifical Council, also changing its name in Pontifical Council for the Pastoral Care of Migrants and Itinerant People. Up to 1970, responsibility for the various sectors of human mobility had been assigned to several offices operating at various Roman Congregations.
In the Pastor Bonus, there is a specific mention to people moving for tourism; it states that the as Pontifical Council is 'an instrument the Pope uses to fulfill his universal mission' (Introduction, n. 7), it 'works to ensure that journeys which Christians undertake for reasons of piety, study or recreation contribute to their moral and religious formation' (art. 151). As a sign of his interest to Tourism, Pope John Paul II undersigned six messages for the World Tourism Day, in the years 1982 and 2000-2004. With the Apostolic Letter Humanam progressionem dated 17 August 2016, Pope Francis has established the new 'Dicastery for promoting Integral Human Development', whichas of 1 January 2017has absorbed also the Pontifical Council for the Pastoral Care of Migrants and Itinerant People.
Tourism might represent an opportunity for the Church to announce its message and to promote moral and religious formation, if one considers that thousands of people every year travel to visit sites of cultural interests and that a wide part of those sites is constituted by religious and sacred sites of the Christian tradition. Heritage sites of religious interest are, indeed, in some countries, even the most part of national heritage. UNESCO website reports that 'approximately 20 percent of the properties inscribed on the World Heritage List have some sort of religious or spiritual connection. These properties to be found in most countries around the world constitute the largest single category on the List' 2 . Italy is an emblematic case, since over 90% of its cultural heritage is bound to the Christian tradition. Visitors to those sites, also if driven by different reasons than pilgrimage or worshipping, are introduced in the Christian tradition, which gives meaning to the site.
This article builds on the stories reported by tourists themselves, to investigate their experience at a religious heritage site. The case of the Basilica of Saint Paul Outside the Walls in Rome, which belongs to the Christian tradition and is part of UNESCO World Heritage, is taken to see which aspects impressed visitors the most and if the artistic beauty of the site facilitated any spiritual experience. Today, the web provides an open space where to share tourism experiences and engage in discussions with other travellers. It constitutes, thus, a rich source where to look in order to collect first-hand data for different kinds of social analysis. In this research, online travel reviews (OTR) about the Basilica of Saint Paul are collected to listen to visitors' stories. The proposed analysis was, in fact, a listening exercise (Cantoni and Tardini 2014).
The article aims at giving two types of contribution to the body of knowledge about the relation among Church, communication and culture. On one side, it intends to bring the attention on tourism as a phenomenon, which unveils social and cultural dynamics of our time. On the other side, the paper gives a methodological contribution, in that it proposes a method to analyze user generated content (UGC) to pursue social science related goals.
The remaining part of the article is organized as follows. The next paragraph (par. 2) provides a literature review covering religion, tourism and culture, as well as the so-called web 2.0 and the touristic experience (par. 2.2). Then a paragraph (par. 3) is devoted to define argumentation and to discuss the peculiarities of OTR, as a specific online argumentative genre. The next paragraph (par. 4) outlines the analyzed corpus of OTR; selected OTR are about the Basilica of St. Paul Outside the Walls, which is briefly presented, as a touristic destination, within the same paragraph. Results are then presented (par. 5) in detail, while a brief final section provides some conclusive remarks and suggestions for further research directions.

Literature review
This section comprises two parts. In the first part, the relationship among religion, tourism and culture is briefly outlined, while in the second one communication dynamics enabled today by the web and their relevance for the field of tourism are introduced.

Religion, tourism and culture
The semantics of the word 'culture' provides a conceptual base to understand the relation among religion, tourism, and culture itself, as shown in Figure 1. 'The English word culture comes from the Latin word cult ura, which derives from the verb colere that means 'to cultivate'. Namely, when the verb was referred to the land or the country, it meant to cultivate the soil (agri-culture), while when it was referred to human beings, it indicated the nurturing and education of the human intellect and its skills (culture in the most common sense). The past participle of the verb col ere is cultus, translated into the English word cult, which illustrates the act of worshipping God. In its modern connotation, these different meanings are combined in the concept of culture: the methods employed to cultivate the soil developed over time according to the practices of different human communities; human intellect and skills need to be constantly cultivated with education and training in order to become civilized adults, exactly as plants need to be constantly nurtured to grow and bear fruit; the spiritual dimension deeply influences all the other aspects of human life.' (Pilgrims in the Digital Age 2016, 5).
Within the international academic community, several discussions have taken and are still taking place in relation to the definition of the person who travels for religious reasons, and about religious tourism as a growing social phenomenon despite the secularization of society. Proof of this is the increasing number of dedicated conferences organized both at the academic and at the institutional level (see, for instance, the Conference on Religious Heritage and Tourism organized in 2016 by UNWTO, and the Religious Tourism and Pilgrimage Expert Conferences, organized every year by an ATLAS special interest group), and of dedicated publications (as for instance the International Journal of Religious Tourism and Pilgrimage (IJRTP), which regularly publishes papers of scholars from around the world).
However, there is not agreement on whether the traveler driven by religious reasons should be seen as a tourist or as a pilgrim (Raj and Morpeth 2007;Rubio and De Esteban 2008;Tsomokou and Velaoras 2009). According to the World Tourism Organization, pilgrimage is part of cultural tourism. Cultural tourism is, in fact, defined as 'the movement of persons due to essentially cultural motivations as study travels, travels to festivals and other artistic events, visits to places and monuments, travels to explore the nature, the art, the folklore and the pilgrimages' (UNWTO). It is not difficult to believe, indeed, that many people travelling to a variety of sacred sites do not have primarily or even any religious purpose or aim at having an experience with the sacred in the traditional sense, but choose the destination because of its cultural or heritage aspects (Petrillo and Lo Presti 2009). There is, then, a pragmatic reason for considering the pilgrim as a tourist: at most cases, the pilgrim spares time, energy and money in places except for the religious place (Tsomokou and Velaoras 2009). A pilgrim, then, is surrounded by tour operators and professional travel counselors, and takes part to predetermined and organized activities (e.g. excursions, meals, holy items trade, etc.).
Faith travel is becoming a growing global phenomenon. According to the World Religious Travel Association (www.wrtareligioustravel.com 2009), it is estimated at $18 billion and counts 300 million travelers. In North America alone, it is estimated at $10 billion and in Italy at $4.5 billion. The Travel Industry Association of America (www.ustravel.com) reported in November 2009 that one over four travelers is currently interested in 'spiritual vacations'.
One of the 'classics' in the field of pilgrimage and comparative religion is the monograph by Nolan and Nolan (1989) 'Christian Pilgrimage in Modern Western Europe', which reports a long-term study when, during over 10 years of research, the authors visited nearly 1000 pilgrimage sites, talked with pilgrims, tourists and service personnel, and made comparisons at geographical as well as devotional level. According to the results of that study (see also Nolan and Nolan 1992), the universe of religious tourism attractions can be conceptualized in three overlapping categories: (a) pilgrimage shrines, that are sites having mostly no particular historic or artistic significance, visited for religious reasons by people from beyond the immediate locality; (b) religious tourist attractions, that are sites of religious significance drawing visitors because of their historic or artistic value; (c) religious festivals, associated or not with pilgrimage shrines, that are sites where special celebrations are organized during religious occasions. As the authors point out, these conceptual categories are overlapping, and there exist various blends of the three basic categories. The classification is useful, however, to investigate and understand tourism-related dynamics of religious sites in terms of their main characteristics, public, tourists' motivations, and site attractions.

Web 2.0 and the tourism experience
Communication is nowadays extensively supported and mediated by means of Information and Communication Technologies (ICTs), both in private and institutional interaction, which is the case also for tourism experiences. Web 2.0 tools, in particular, 'enable user participation on the web and manage to recruit a large number of users as authors of new content' (Kolbitsch and Maurer 2006, 187). The term Web 2.0 was coined in 2004 to refer to the transition from static HTML web pages to a dynamic web, where there is not any more a clear distinction between information providers and consumers. Web 2.0 gives users several opportunities to voice their opinions and to share contents, which encompass a variety of media forms and types of websites and are commonly called UGC (Cantoni and Tardini 2010). UGC represent an increasingly used source of information, and are more credited than official sources, because they are considered genuine, authoritative and not business-driven. However, since online reviews can be published without any author information, they might also be exploited for deception (Donath 1999), for instance by individual product or service providers for the purpose of promoting their business. Platforms for online reviews list sets of criteria for reviewers, which are intended to prevent circulation of offensive, false or deceptive information. TripAdvisor, for instance, among its criteria for reviewers mentions that reviews must 'offer trusted advice from real travellers' (http://www.tripadvisor. com/pages/about_us.html), that means that contents created by users must be first hand experiences and give a substantial contribution to the issue discussed. Even though, except for filtering messages with inadequate language or inappropriate content, it is hard for platforms managers to detect deceptive reviews. The issue of deceptive reviews identification, in fact, has been widely investigated, mostly applying general communication and deception theories, but except for some stylistic markers that may help to unmask cheats, there is not any method to unveil the writer hidden behind the screen (Yoo and Gretzel 2009).
Tourism-related UGC usually reflect the experience of the tourist at specific destinations, her evaluations and reactions about the experience as well as about the destination itself (De Ascaniis and Cantoni 2014). UGC can equate electronic word-ofmouth (eWOM), and are of the utmost importance in shaping destinations' image and reputation (Marchiori and Cantoni 2012). WOM has always been an elective channel to spread and collect information, since it is a social dynamic naturally occurring in the interaction among people. WOM can be even considered as the primary enabler of economic and social activity in most of the ancient and medieval communities, which had not yet established formal law systems of contract enforcement. WOM has been showed to play a major role for customers' buying decisions, and WOM from friends and relatives has been found to be the most commonly used information source for travelers before they make a travel decision (Beiger and Laesser 2004;Inversini, Cantoni, and Buhalis 2009).
Among the different forms in which content is shared online, OTR are the prevalent form in the field of tourism (Xiang and Gretzel 2010). They represent people's wish to share their travel experiences online, recommending a tourism product or complaining about it. OTR share with the other types of UGC the fact that they are directed toward an unknown audience and are at free disposal. They then distinguish themselves for some characteristics: OTR are monographic texts reporting on and evaluating (usually) a single product/service or experience, differently from forum posts, which are dialogical moves in an asynchronous discussion and can cover different topics, and differently as well from travel blogs, which resemble diaries; OTR, then, represent one-to-many communication and typically one-way information flows.
When reporting a travel experience, people do not just tell their stories nor do they only provide information about places and services, but make claims about those places and services and give reasons supporting their claims (De Ascaniis and Greco Morasso 2011). OTR are, indeed, an argumentative type of text, where the opinions given are backed by values, beliefs, expectations about the very idea of travel and tourism. Analyzing OTR allows, thus, to get closer to people's most personal experiences and better understand them. They also represent a valuable source of information for travel agencies and destination management organizations, in that they collect opinions of visitors, on this base adjusting or even differentiating the cultural promotion of the site and its communication (De Ascaniis and Cantoni 2016).
The argumentative relevance of OTR is what makes them worth to be considered when investigating social and cultural dynamics related to tourism, in particular to understand tourists' preferences and visit motivations. The analysis of OTR related to a site of the religious heritage, thus, allows to point out the aspects of the site, which impressed visitors the most, and to extend some observations to religious sites as a type of tourism attraction.

Theoretical base
This section provides a theoretical base to analyze OTR. They are characterized as an argumentative type of text where the reviewer, while making his argument, suggests to the reader which line of reasoning to follow to make a travel decision. Before that, a brief overview of what is meant with argumentation is given.

What is argumentation?
Argumentation is the form of reasoning used for decision-making, and the argument is the logical basis for practical reasoning, that is, when one has to make a decision, he engages in an argumentative process (Perelman and Olbrechts-Tyteca 1969). Argumentation 'is generally considered to consist of a set of statements put forward to support or rebut, or justify or refute, some other statement' (Houtlosser 2001, 27). Despite the different ways in which the object of argumentation is characterized by various approaches, three main elements can be distinguished: standpoint (claim or position), argument and counter-argument. Van Eemeren and Grootendorst characterize a standpoint as 'an externalized position of a speaker or writer in respect to a formulated opinion ' (2004, 5). An argument is the reason given to justify such position, while a counter-argument is a reason given to refute that position or to refute the argument supporting that position. Below is an example, taken from the corpus of OTR used for the analysis. When arguing, one has in mind an ideal public he wants to convince with his argument. The knowledge of the public one aims at convincing is a necessary condition for the success of argumentation. A reason which results to be convincing -'good'for an audience, can turn to be unacceptable, weak or misunderstood by another. This happens because of the non-necessary nature of the premises in an argumentation: they are, in fact, endoxa, that are common opinions or beliefs shared by a community. The Aristotelian notion of endoxon refers to the set of propositions that constitute the common ground of a community and are, as a consequence, generally accepted, reliable and credited within that community. The use of endoxa helps to understand the process of grounding a standpoint: they are employed as implicit or explicit premises in the argumentative interaction, this way letting the conclusion (standpoint) to follow from the premises (argument) (Tardini 2005). An endoxon works as implicit premise for the inferential chain of reasoning underlying an argument. Indeed, most of the content of communication is normally left implicit because it is thought to be easily retrieved by the interlocutor exactly thanks to the endoxa.
In the example above, there are at least three types of endoxa at play. The main argument (Argument 1) is grounded on the idea of uniqueness, which represents a value for the community of tourists. It is, in fact, a common belief of tourists that an attraction is worth a visit if it has something special, which distinguishes it from the many others that might be visited. The first subordinate argument (Argument 1.1) builds on the value that is grant to the burial place of a person by the community of people, for whom that person represents a witness or an icon: in this case, Saint Paul represents a witness for the community of people sharing Christian faith. Finally, the value of the originality of an attraction is exploited to add to the attractiveness of the church: even if the original Basilica was destroyed by a fire, it has been rebuilt in such a faithful way to retain 'all the power and majesty of the original basilica'. Originality represents, indeed, a value for visitors, which justifies the visiting choice of an attraction among others.

The argumentative texture of OTR
OTR present an eminently argumentative structure, where the standpoint is constituted by the travel advice, and the argument is the reviewer's opinion about the destination. Thus, the main argumentative move of OTR can be generically expressed in these terms: 'I advice/recommend you to visit x, because x is y OR because my experience in x was y'. This argument becomes, in turn, a standpoint for a lower level argumentative move, where data are provided by the reviewer to support her opinion. Data can be, for instance, descriptions of attractions or reports of travel events (see Figure 2). Numerous multiple arguments and (some) counter-arguments are provided to support or reject the standpoint: reviewers try to provide quick and easy comments (i.e. arguments) on key aspects of the destination, highlighting those aspects that were of relevance for them, or impressed them the most. The travel advice (stdp 1) is frequently left implicit in OTR, because it can be easily inferred by the reader since it derives from everything that is said in the review. Also, the grade assigned to the attraction/destination, usually expressed with symbols like bullets or numbers, constitutes a non-verbal way to express the travel advice (De Ascaniis 2013).
To make their point, reviewers rely on three main inferential principles or argument schemes. Argument schemes 'are conventionalized ways of displaying a relation between that which is stated in the explicit premise [i.e. the argument] and that which is stated in the standpoint [ … ] An analysis of the argument schemes used in a discourse produces information regarding the principles, standards, criteria, or assumptions involved in a particular attempt at justification or refutation' (Van Eemeren 2001, 19). They are abstract structures to which actual arguments can be ascribed.
The communicative effectiveness of OTR is due, in the first place, to the authority of the reviewer, who 'knows' the facts because he was there. This corresponds to the argument scheme called argument from position to know (Walton 1997(Walton , 2006)which is a particular type of argument from authoritywhere the standpointhere the visit recommendation (stdp 1)is supported by an argument referring to the position of the person who puts it forward. The argument supporting the standpoint is often left implicit because it is presupposed, and can be expressed in this terms: 'I recommend a visit to site X, because I was there and I know about it'. This argument, indeed, is connected with the very idea of eWOM: the report of others and their opinions are credited because they are based on the first-person experience of the person giving the advice. Moreover, it is assumed that authors of OTR are laypeople, similar to us and not moved by any economic interest when they recommend or criticize something.
A second type of inferential principle that is frequently exploited in OTR is the argument from parts to whole, in which properties of constitutive parts of the wholee.g. attractions, food, peopleare attributed to the whole, i.e. the destination (Rigotti andGreco Morasso 2009, 2010).
One-third argument scheme, which is indeed the very base of the OTR logic, is the one that represents the basic scheme for practical reasoning: the argument from final cause (Walton 2006;Rigotti 2008). Here, the advice of performing some course of action is justified by its consequence that is the possibility to reach a desirable/good goal. A means-end relation between standpoint and argument(s) is typical of suggestions: the reviewer indicates which action (means) should be performed in order to reach a desirable goal (end) related to the travel experience.

Methodology
In this section, the theoretical base provided by argumentation theory is applied to the analysis of a corpus of OTR. First the corpus of data is presented together with the destination they deal with, then the analytical procedure is described.
The method used for the analysis represents an innovation in the study of tourism-related UGC, which mostly adopt a quantitative approach. Some studies focused, for instance, on the ranking obtained by specific destinations on social media websites (Dowling 2008), some others on the frequency of keywords and their relationship (Pan, MacLaurin, and Crotts 2007), and also models have been developed with the specific aim of classifying the content of online dialogues around a destination (Inversini et al. 2010), but seldom analyses of UGC content itself have been conducted (De Ascaniis and Greco Morasso 2011; De Ascaniis and Gretzel 2013). In general, using a quantitative approach to UGC does not tell us the whole story about how users read their fellow travelers' comments and why they might influence their decisions.

The corpus of data
For the study presented here, a religious tourist attraction was taken as case study: the Roman Basilica of Saint Paul Outside the Walls. The site is, indeed, for many visitors, primarily a pilgrimage shrine. In the occasion of the 2000th anniversary of his birth, Pope Benedict XVI dedicated a special Jubilee year to the Apostle Paul, which started on 28 June 2008, and was officially closed on 29 June 2009. The Jubilee year attracted to the Basilica a number of pilgrims from all over the world, because 'questa Basilica vuole essere la testimonianza viva e vitale dell'insegnamento e dell'esempio di Paolo per additarlo a tutto il mondo e continuarne la sua opera' [trans. by the authors: 'this Basilica intends to be the living and vital testimony of Paul's teaching and example, to show it to the whole world and to carry on Saint Paul's missionary work'] (Cordero Lanza di Montezemolo 2009, 23). Saint Paul's Basilica is one of the most visited attractions in Rome: TripAdvisor (TA) ranks it among the first 10 sites of interest in Rome (among 880 ones), and among the first 20 'things to do' in the city (out of more than 1400). It has received on TA over 3400 travel reviews in all languages (as of end of 2016), the greatest majority of them assigning to it an excellent (over 2700) or very good (nearly 600) rate. Most of the reviews are in Italian language (over 1300), followed by OTR in English language (over 1000). In this research, a corpus of 800 OTR was collected, starting from the first one ever published by the platform, that is dated 2 May 2007. The corpus comprised the first (chronologically) 400 reviews in the Italian language and 400 reviews in the English language; OTR were analyzed in their original language.
Among the many platforms for travel reviews, TripAdvisor is nowadays the largest Web 2.0 company in the northeast and the largest travel site in the world: its branded sites together attract more than 56 million unique monthly visitors, and publish over 75 million reviews and opinions. 4 TA, then, has the highest ranking in search engines among travel-related social media.
In the following section, some historic and artistic aspects of the Basilica of Saint Paul are presented.

Saint Paul outside the walls: between religious and heritage tourism
It is Rome's largest patriarchal basilica after St Peter's in the Vatican. It is located at about 2 km outside the Aurelian Walls surrounding Rome and is property of the Holy See, enjoying extraterritorial rights. It was founded over the burial place of Saint Paul, immediately after the Emperor Constantine issued the Edict of Milan in 313, which marked the end of the Christian persecutions and conferred on them freedom of worship, encouraging the construction of places of prayer. The actual Basilica has an imposing Byzantine structure, 131.66 m long by 65 m wide, rising to a height of 30 m, comprising five naves, supported by 80 monolithic granite columns. Throughout the centuries many Popes restructured and embellished the Basilica with frescoes, mosaics, paintings and chapels. Famous is the series of papal portraits, which go round the top of the nave and the transept with 265 round mosaics. On the night of 15 July 1823 a terrible fire almost entirely destroyed the Basilica leaving hardly any of the structures and works of art intact, and most of the walls had to be rebuilt. The 'new' Basilica was consecrated on 10 December 1854 by Pope Pius IX (18461876), on the occasion of the proclamation of the Dogma of the Immaculate Conception. The Basilica has been designated as a National Monument by the Italian Government due to its artistic and aesthetic value and has been inscribed in the UNESCO World Heritage list in 1980, together with the historic center of Rome.

Analytical procedure
The corpus was analyzed to identify and classify the arguments given by visitors to support a visit recommendation to Saint Paul. An iterative analytical procedure was adopted, as shown in Figure 3. The first step was to identify the arguments of one review and classify them; then a second review was considered, classifying arguments according to the previously defined categories. If new types of arguments were found, new categories were created and added to the classification scheme. The second step was repeated until the saturation level, that is until no new category was found in the texts, but the existent categories were enough to categorize all the types of arguments retrieved. No unclassified residuals were left.
The corpus was annotated and analyzed using UAM Corpus Tool version 2.8.12, a software for human and semi-automatic annotation of texts and images, developed by Mick O'Donnell. 5 UAM allows the user to explore linguistic patterns and linguistic features in a text, which cannot be explored with simple concordances, and which cannot be automatically tagged because they pertain to the semantic or pragmatic level. The central concept of UAM is the project, consisting of a corpus of text files, which can be annotated at a number of linguistic layers; for each layer, the user can  provide a hierarchically-organized tagging scheme. UAM also provides statistical functionalities for the analysis of corpora, which range from general text statistics such as the total number of annotated segments and the number of words per segment, to feature coding, which allows to consider specific categories in each layer and describe their usage in the corpus at that layer in terms of count, mean and standard deviation (e.g. how many times the argument type 'internal decorations' has been used within the arguments category 'appearance'). UAM also allows compiling the frequency of keywords and to represent it through a word-cloud.

Results
In this section, the categories of arguments and their relevance within the corpus are presented.

Arguments' categories
Given the empirical iterative process of OTR analysis and classification, the categories of arguments constitute a taxonomy rather than a typology. Figure 4 illustrates the taxonomy of arguments, as emerged from the analysis of the corpus. In what follows, a characterization of each argument type is given, and examples from the corpus are supplied.
Only 25 OTR in the corpus assigned a rate of 3 out of 5 points to the attraction, while all the others assigned 4 or 5 points that means a 'very good' or 'excellent' rate. In fact, negative arguments were very rare and diverse, and they have not been classified because were not representative. Only one type of negative argument was classified, which was encountered 8 times in the corpus: the fact that the Basilica is not the original building, but was restored after a fire, thus what a visitor sees is a copy. This same argument is instead used positively by 19 reviewers, who points out that despite the Basilica is a copy, it has been faithfully restored, and thus one can still admire it as it was originally designed. An example is the following: 'While the church was rebuilt after a fire, it retains all the power and majesty of the original basilicas. 6 ' (Twerner, 17.01.2013) In the taxonomy, two groups of argument types supporting a visit can be distinguished: (1) arguments related to the Basilica of Saint Paul as a cultural attraction, and (2) arguments related to the Basilica as a site of the religious heritage. Types of arguments have to be intended as independent from the specific attraction, since they do not refer to singular elements of it, but rather to aspects that characterize cultural attractions as a type of touristic attractions. In the case of the Basilica of Saint Paul, for instance, all the arguments where the reviewer refers to aesthetic characteristics of the church like the mosaics in the apse or the portraits of the Popes all along the arches of the nave, were codified with the argument type 'appearance' and, in a finer classification, with the argument sub-type 'internal decorations'.
1. Argument types related to the Basilica as a cultural attraction, which might be applied to any other cultural attraction, are the following ones: 'appearance', which refers to all those arguments that exploit aesthetic characteristics of the attraction, like architecture, decorations, works of art. Arguments in this category can be further classified in: 'overall appearance', when the opinion is generally referred to the aesthetic beauty of the attraction without any further specification, as in 'It is beautiful grand, opulent' (timmyjt, 7.04.2013), or in 'It is as though every thing is a piece of fine art!' (Betty L, 21.02.2013); 'interior', when architectural elements of the interior of the Church are commented, as in 'rare and marvelous windows made in alabaster, astonishing colonnades made of marble ' (Ondina_2011, 10.05.2013  'restoration', as in 'this church burnt down and rebuilt in the same image' (jepoyzia, 3.01.2012). 2. Argument types related to the Basilica as a site of the religious heritage, which might be applied to any other site of religious heritage, are the following ones: 'for anyone', when the site is presented as a place of interest for anyone despite his/her religious belief, as in 'This is a wonderful place even if you are not religious' (M C, 6.08.2012); 'cult-related', that are arguments where the dimension of cult and worshipping are stressed. Three subcategories might be distinguished: 'burial place', when the attraction hosts relics or the tomb of an important person in the history of the specific religion, who is worth to be praised or is recognized as a testimony, as in 'First and most importantly, it is the resting place of St. Paul. One may pray in front of his tomb' (twerner, 17.01.2013); 'facilitates cult', when the attraction is commented as a mediator of a religious/spiritual experience, as in 'Rarely am I moved by a religious location or building, but this basilica was different. It was deeply moving' or in 'the architecture and atmosphere of this Constantinian basilica, as well as its removal from the bustle of the city, makes St. Paul Outside the Walls something of a spiritual retreat' (lewisstruppi, 24.08.2012); 'religious service', when the possibility to benefit from any kind of religious service related to the specific religious creed is commented, as in 'we loved [ … ] the confessor waiting for penitents' (valuewise1, 3.04.2012).

Analysis of arguments
In total, 1270 arguments were codified, 545 in OTR in English language and 717 in OTR in Italian language. This suggests that visit recommendations of Italian-writing reviewers were justified with arguments more than those in English; in fact, in the English corpus, OTR giving only the visit recommendation without any argument to anchor it were more frequent than in the Italian corpus. The argumentative effect of this kind of OTR has to be ascribed to the 'argument from position to know', which is a constitutive characteristic of OTR as a specific type of textual genre. Following is an example of an 'empty' OTR, where a visit recommendation is made ('Must go') without supporting it with any argument than an overall judgment ('Incredible. Amazing. [ … ] beautiful', that corresponds to stdp 2): 'Must Go' 5/5 Reviewed February 25, 2013 Incredible. Amazing. It is one of the most beautiful places I have ever seen. On weekend is full, go during the week.
(Sura Ozi F, 26.02.2013) Table 1 reports the occurrence of each argument type in the corpus, distinguished according to the language of the review.
In both the English and the Italian sub-corpora the most used arguments to recommend a visit to Saint Paul concern a) its aesthetic characteristics and b) aspects related to the religious cult.a) The Basilica is overall described with words praising its size and artistic beauty, as 'maestosa' [majestic], 'imponente' [imposing], 'enorme' [enormous], 'grand', as shown by the word-cloud in Figure 5, which highlights the most frequent keywords in the argument type 'overall appearance'. The artistic value of the Basilica is recognized in its internal as well as external features; visitors are particularly impressed by the internal decorations, especially the portraits of all Popes of the Catholic church, the golden ceiling and the mosaics in the apse and in the external façade, as shown by the word-cloud of the most used keywords in the sub-argument type 'appearance -internal decorations' (Figure 6). The aesthetic beauty of the Basilica is by far the most used argument by Italian-writing reviewers, constituting 71.0% of all the positive arguments expressed by them. Also English-writing reviewers largely exploit this type of argument (52.3% of all the positive argument types), but they also very frequently suggest the visit because of cult-related reasons (24.4% of all positive argument types vs. 12.3% for Italian OTRs).b) With regard to the arguments related to the religious cult, a difference emerged between the Italian and the English sub-corpus. In the Italian sub-corpus, in fact, the Basilica is suggested for a visit mainly because it facilitates cult (about 52.3% of all the arguments belonging to the type 'cult-related') thanks to its peaceful atmosphere, to its majesty and beauty that enlarge the spirit. Figure 7 highlights the keywords used in the argument type 'facilitates cult' in the overall corpus. The English-speaking reviewers, instead, primarily stress the fact that the Basilica is the burial place of Saint Paul (66.9% of all the arguments belonging to the type 'cult-related'), thus represents a pilgrimage shrine for Christians but has a value also for non-Christians, because of the historic relevance of  Figure 5. Keywords used to comment on the Basilica's overall appearance.
the apostle Paul. Figure 8 shows the keywords that are representative of the arguments in the corpus belonging to the category 'cult-related'. The Basilica of Saint Paul is 'off-the-beaten-track', as it can be read in many reviews, because of its location out of Rome city center. For this reason, it is often left out of city tours and visited mostly by spontaneous or fortuitous tourists, thus it is usually not crowded. This aspect, added to its grandeur, the beauty of its art and the historical traces of the apostle Paul, contributes to create a 'peaceful' and 'intense' atmosphere, which allows meditation and spirit lifting. Figure 9 shows the keywords used in the arguments type related to the atmosphere, which constitutes 7.8% of all   the positive arguments, both for Italian and English reviews. Visitors also appreciated the elements of the Basilica, which speak of its story and of the culture it is bound to (6.1% of all positive arguments), like the relics of Christian Saints and martyrs and the museums with the ruins of the original Basilica. A difference emerges between Italian-writing reviewers and English-writing reviewers: arguments referred to history and culture are more used by the latter (8.6% of all positive arguments in the English sub-corpus), while they are only seldom reported by the former (4.2% of all positive arguments in the Italian sub-corpus). This might be explained with a sort of habit Italians have to be in contact with cultural attractions coming from ancient times, given the richness of Italy in terms of cultural heritage from the past and from Christian tradition.
Finally, a small part of the positive arguments concerns the maintenance of the church (4.4%) and the fact that, despite it is a site of the Christian heritage, it is worth a visit for anyone (1.3%). The cleanliness and the order of the inside and the outside of the Basilica are granted to the Benedictine monks, who live in the cloister; their 'ora et labora' (pray and work) rule, which beats their time and organizes their activities, contributes to create the serene and sacred atmosphere.

Discussion and conclusion
Tourism is an opportunity of personal growth, both for the traveler, who leaves the known for the unknown and is exposed to new perspectives and cultural traditions, as well as for the host, who in the encounter with the foreigner shares part of his/her own identity and welcomes the other. Tourism, then, is an experience that needs to be communicated, because it is an extraordinary time for nurturing the spirit. Communication is nowadays increasingly mediated by ICTs, which enable an eWOM that is an extensive sharing of experiences and opinions. In the article, a study was presented, where the voices of travelers who visited an attraction of the Christian religious heritage were listened to, with the goal of unveiling the aspects that contributed to make their experience extraordinary. They represent, thus, the reasons that justify a visit recommendation.
The arguments given by travelers in their OTRs to recommend a visit to the Basilica of Saint Paul Outside the Walls were identified and classified. It was neither an analysis of the topics discussed in the reviews nor a classification of the sentiment expressed, but rather an analysis of the reasons provided to support a personal opinion on that heritage site. Arguments represent an act of reasoning that goes beyond emotions and grounds the judgment on experience; they are, indeed, the basis of decision-making. In the field of tourism, OTRs represent one of the most common forms of information source and their argumentative nature is what makes of them an influencing factor in travel decision-making.
The types of arguments put forward in OTRs depend on the type of tourism product (i.e. destination, attraction, accommodation, catering service, etc.) that is reviewed. The study presented in the paper allowed to point out the types of arguments, which ground the opinions on a cultural attraction. Its attractiveness is mostly given to: the atmosphere it creates and which contributes to shape the tourism experience; aesthetical aspects of both the interior and the exterior of the attraction, as well as the harmony between the two of them; the care that is put in its maintenance, which is a symptom of the value it has for the host and which is passed to the visitor; the connection the attraction has with a culture and its past, which promotes a learning experience.
An attraction of the religious heritage, then, elicits some other specific arguments, which are related to the possibility to 'cultivate God', thanks to material features that help the religious experience, like relics of witnesses of faith and religious services. Visitors to attractions of the Christian heritage, then, often positively report about the fact that they are open to anyone despite their creed: accessibility to places of worship is a sign of the ecumenical/universal (hence 'catholic') character of the Church, and gives anyone an opportunity to learn about the Christian message.
It clearly emerges from the analysis of visitors' arguments that the artistic beauty of the site might become a mediator of a spiritual experience, as it can be read in the following extracts: From the moments you set foot on the grounds, you are met with overwhelming beauty, art and spiritual inspiration. (scrapbookmarie, 29.09.2012) San Paolo l'Apostolo delle Genti, ha a Roma una Basilica fuori le Mura Pontificie, meravigliosa ricca d'arte in stile bizantino, dove si respira aria di pace e di tranquillit a dove la fede e appagata dagli affreschi e mosaici che adornano la Basilica. (tr. Saint Paul, people's apostle, has in Rome a church outside the Walls, which is wonderful, rich in Byzantine art, where there is a peaceful and serene atmosphere and where faith is satisfied with frescos and mosaics.) (dolly, 25.03.2013) This is in line with the pastoral proposal of the Pontifical Council for Culture called via pulchritudinis ('The Way of Beauty'). In the concluding document of the plenary assembly of 2006, this Pontifical Council defined the via pulchritudinis as a privileged pathway for evangelization and dialogue because 'beginning with the simple experience of the marvel-arousing meeting with beauty, it can open the pathway for the search for God', especially to those, 'who face great difficulties in receiving the Church's teachings, particularly regarding morals.' In fact, 'beauty itself cannot be reduced to simple pleasure of the senses: this would be to deprive it of its universality, its supreme value, which is transcendent'. All Christian artwork, then, 'has such a meaning: it is, by nature, a "symbol", a reality that refers beyond itself which leads along the path that reveals the meaning, origin and end of our terrestrial journey. Its beauty is characterised by a capacity to move from the interior 'for self' to that of the 'more than self'.' (Pontifical Council for Culture 2006).
Furthermore, the analysis of the arguments used by visitors to report about a travel experience at a specific destination or attraction allows to let emerge the dominant perceived touristic value of that destination/attraction. In the case of Saint Paul Outside the Walls, the touristic value is given by the combination of a material feature that is the magnificent architecture, with an aspect of the intangible heritage of the Christian tradition that is worshipping an Apostle of faith at his burial place. The touristic value can be exploited by destination management organizations and tour operators to better promote the destination/attraction on the market, leveraging on its most appreciated aspects and diversifying the message per touristic segment.
From the point of view of computational studies, then, the argumentative analysis of OTR and the classification of arguments per type of tourism products, might provide information systems developers with indications for helping online users in the process of information seeking and selection. It may, in fact, direct the development of algorithms both to rank reviews in terms of their argumentative quality, and to filter them according to their potential usefulness to consumers.
Finally, the analysis presented in the paper allowed to point out differences between OTR in Italian and in English language, which are a symptom of differences in visit preferences and appreciation, which might be due to different cultural contexts. Italian-writing reviewers, for instance, stressed especially aesthetic aspects of the attraction like the internal decorations and artworks, while English-writing reviewers stressed the fact that the church is the burial place of a witness of faith. Also, the argumentative texture of OTR seems to be somehow influenced by culture: OTR in Italian language present in general more arguments than those in English language. These observations should be validated and extended analyzing a wider corpus of OTR, which should include OTR about other attractions and in other languages; moreover, the nationality of reviewers should be taken into consideration (e.g. people from many nationalities, including Italians, might write in English, and the same can be said about people writing in Italian).
In this research, the focus has been put on travelers' voices, as a source of information about a heritage attraction and a base for tourism decision-making. In future research, official information provided by tourism suppliers should be considered, to investigate how heritage attractions are presented and promoted, in particular if their cultural significance is explained. Furthermore, the role of ICT in tourism at religious sites should be considered, in order to investigate if and how they can enhance visitors' experience.
To further validate the proposed taxonomy and to identify religion-specific types of touristic arguments, a similar research about religious attractions linked to other religions should be done.