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Share, Comment, and Like on Facebook and Message Strategies of Non-Governmental organizations

The scope of this study is to examine the relationship between message strategies and stakeholders’ responses on Facebook. Data on 20 non-governmental organizations’ Facebook pages was collected by simple random sampling to examine their communication practices on social media. It was found that those organizations were more likely to adopt Public Information (PI) model to transmit information to their stakeholders. Organizational messages based on Two-way symmetry model (TWS) can generate the greatest number of Likes which is significantly larger than Press Agentry (PA), Public Information (PI), and Two-way asymmetry (TWA) models. The multi-way (MW) model was proposed in order to extend Grung & Hunt’s framework in the digital era.


Introduction
According to the Two-Way Symmetric model (TWS) in dialogic communication theory suggested by Kent and Taylor (1998), dialog is the output generated during the process of communication, which involves sharing of thoughts and viewpoints characterized by intersubjectivity. Relationship building is a foundation for public relationships, and social media as a dialogic medium and "convivial tool" brings about the creation, adaptation, and change of organizationpublic relationships. Kent and Taylor (1998) suggested organizations to establish dynamic and long-lasting online public relationship, such as to start and maintain conversations by encouraging feedbacks and providing professional and timely responses; and providing useful content that can address public interests, values and concerns. Social media adopts dialogical communication technology to connect people, which may stimulate the democracy of information reception and participation among family and friends (Kent, 2013). Social media platforms provides useful channels for marketing and customer account management (Alalwan et al., 2017). Apart from marketing and advertising, Public Relations (PR) professionals can also use social networking services for a tool to benefit the society through problem solving and crowdsourcing (Kent, 2013).
The 15-year Excellent Study set in the US, Canada, and the UK, is the most large scale study in the public relationship (PR) discipline, it explained the worth of PR to organizations, identified a series of guiding principles that served as a benchmark for education and measuring the efficacy of PR (Grunig & Grunig, 2002). In finding ways of solving disputes, negotiation method could be used (Schelling, 1980). The symmetrical nature of excellent PR should be more than conventional strategies in communication theory, which stressed on persuasion, advocacy and message strategies design; whereas more attention should be paid on relationship management through dialogic conversations, managing conflicts, listening, and corporate social responsibility (Grunig & Grunig, 2002). PR communication is not only used for addressing the concerns of external stakeholders; but also being used to manage the relationship with internal stakeholders. A study conducted by Duthler and Dhanesh (2018) in the UAE found that the twoway asymmetrical communication model adversely predicts employee perceptions of Corporate Social Responsibility (CSR), whereas the Two-Way Symmetric communication strongly predicted employee engagement.
Besides, social media is commonly applied by non-governmental organizations (NGOs) in branding, community engagement and education. Some NGOs design social media graphic for free download, for example, Facebook profile picture frame, a typical example is "Love has no labels" launched in 2015, which is a campaign promoting the equality of everyone (Ad Council, 2020). Some organizations collaborate with cartoonists to create emoticon stickers pack that contains educational messages or local slangs, examples including World Wild Fund (2020) in Hong Kong.
Facebook is the most powerful social media site globally, which had over 2.60 billion accounts as of year 2020 (Statista, 2020). Previous studies focused on the function of social media in promoting products and services (Kapoor et al., 2018), some past literature suggested public relations practitioners to utilize the potential of dialogic communication on Facebook for maintaining close relationship with stakeholders (Bonsón Ponte et al., 2015;Ihm, 2015;Kapoor et al., 2018;Warren et al., 2014;Waters et al., 2009;Wut and Yu, 2016). Charitable organizations and non-governmental organizations (NGOs) usually concern about their public relations budget; they try to keep their costs reasonable and social media could be one of the cheapest ways to reach wide range of target audiences (Coombs & Holladay, 2012).
Only a few studies, such as Cho et al. (2014) and Nordström (2012), discussed communication strategies used by NGOs on Facebook under Grunig and Hunt's (1984) "four models of public relations" framework. There is a few of research in social media messaging strategies applied by NGOs. Thus, this study seeks to examine various types of Facebook messaging strategies used by NGOs and the related effects on the level of stakeholder's engagement.

Background
According to the recent Global NGO Technology Report, among the 5,721 NGOs in 160 countries surveyed, 90% use social media for regular engagement with donors and followers, and 44% of NGOs have a digital marketing strategy (Nonprofit Tech for Good, 2019). About 47% perceived social media very effective communication and fundraising tools for them and 37% thought it is somewhat effective. Respondents perceived social media an effective useful online tool to promote brand awareness (94%); recruit attendees for events (80%); advocate social changes (78%); recruit volunteers and inspiring people in taking political action (75%); and participate in online fundraising (72%). Facebook is considered the most popular platform used by NGOs (84%), followed by Twitter (46%), LinkedIn (28%), WhatsApp (28%), and YouTube (26%; Nonprofit Tech for Good, 2019). According to the same survey, majority of NGOs (97%) own a Facebook Fanpage, around half of them share Facebook Stories (54%), buy Facebook Ads (47%), maintain a Facebook group (44%), use Facebook Live (43%), and some even use Messenger bots (36%), and Facebook Charitable Giving Tools (29%; Nonprofit Tech for Good, 2019).
China is an exceptional case under the PRC government's internet censorship; WeChat and Sina-Weibo are the most popular social networking sites among Chinese. Ruellea and Peverelli (2017) carried out a case study of an NGO in China, which explored theirconstruction of social identity in ongoing instant messaging discussions. Online activities on WeChat over several months were analyzed, it proved the functions of social media as a discursive space for a charitable organizations in China. These functions include drawing attention on recurrent issues, encouraging members to participate in conversation, and growing trust, so as to establish and strengthen their sense of belongings. With the presences of loyal followers who are "broadcasters" or "supervisors," social media may facilitate development of non-profit organizations (Ruellea & Peverelli, 2017). Zhou and Pan (2016) observed 155 educational NGOs in rural areas of China for 6 months on Sina-Weibo, they found that regardless cyber censorship and the relationship with the Chinese government, NGOs were still active on Weibo. Similar to NGOs in other parts of the world, they spread information, form communities, and mobilize resources on social media. As Chinese NGOs commonly faced legitimacy problems under national policies, aside from attracting followers, they also use social media to broadcast organizational legitimacy. Besides, these organizations also massively employ internet slangs and emoticons to achieve sense of intimacy with younger generations; with the purpose of drawing attention on Weibo, many publish posts on popular topics not necessarily related to their area of service (Zhou & Pan, 2016).

Literature Review
NGOs need to consistently interact with target audience so as to maintain strong connections with the society, even though virtual communication cannot replace physical interaction, the comment, like, and share functions of social is more far reaching when comparing with traditional practices of face-to-face communication. Larger scale NGOs can afford to set up websites for information sharing, but for smaller organizations may need to rely on social media as the entry requirement is much lower, like setting up a Fanpage and account for free, making announcements and reaching out for with possible future donors, alliance organizations, and community members. Thus, they may have to spend certain budget to buy advertisement from the service providers in order to boost the viewing rate (Armstrong & Butcher, 2018).
There has been more research regarding NGO social media usage in developed regions such as America and Europe, mostly case studies on thematic topics. NGOs social media usage in developing regions are less likely to have a broad impact due to technical problems, such as low Internet penetration rate. Armstrong and Butcher (2018) analysis twitter content of 151 Nigerian NGOs, and found out that NGOs mostly perform single-way communication on social media, those posts are informative yet with low interactivity, and become less effective in furthering relationships between the organizations and their recipients. Some people may be reluctant in using social media due to privacy concerns of digital footprint; while this may be less a concern for those who live in regions with vibrant democratic civil society. For those who live under oppressive regimes may even have unique safety threats (Armstrong & Butcher,2018). Rodriguez (2016) investigates how LGBTI asylum-specific NGOs used Facebook and Twitter for relationship building with general public. Among the three functions investigated, the two LGBTI global NGOs based in the US utilized social media for disseminating news and facts on human rights and legislation in foreign countries, more than for community building and actions of fundraising, recruitment of staff or volunteers, and advocate causes. Moreover, they did not engaged in social media platforms for videos photos in comparison to mainstream NGOs (Rodriguez, 2016).
McPherson (2015) identified two models for NGO social media journalism, namely the evidence model, which is largely assessed under the time based process and expertise; and the engagement model, as evaluated by participation in the process of information production and distribution.
Carrasco-Polaino et al. (2018) investigated the type and subject matters of photos posted on Instagram during 2017, by the 20 NGOs that work on "artivism" at international level, to identify their choices of formal elements in the use of children images. They found that typical NGO post is an image of an aid recipient, usually in a child alone or female, facing the camera in a middle to close up shot, posing a positive feeling gesture, which suggests the benefits of donating to that NGO. Although such prototypical images are often used by NGOs, but the type of image generating greater engagement were those containmiddle-aged NGO co-operators or volunteer who shows a smiling gesture (Carrasco-Polaino et al., 2018).
There are a few related studies on crisis management of NGOs. del Mar Gálvez-Rodríguez et al. (2019) used the situational crisis communication theory to perform an analysis of online activity by NGOs during the Syrian refugee crisis. As the public more often criticize the public sector than private sector when it comes to immigration issues, NGOs were much more proactive than governments in terms of crisis communication. During humanitarian crises, NGOs should emphasize that the beneficiaries in the local communities are active contributors in recovery and rebuilding, social media provide a channel for such engagement (del Mar Gálvez-Rodríguez et al., 2019).

Public Relations and Social media
Nowadays everyone on social media is able to spread information, yet Verhoeven et al. (2012) found that not many European NGOs performed the role of gatekeepers. It is suggested for organizations to monitor their regular activities using key performance indicators. Besides communication modes and content, advertising affects the content over social media, Dhanesh and Duthler (2019) identified the relations between ad recognition and awareness of paid endorsement, in correlations with eWOM, purchase, and influencer-follower relationship.
A few reviews of related scholarly articles have been done in recent years.  selected 155 articles over 35 years, and found that digital PR literature were lopsided to new media as tool, but generally neglected media stakeholders and public, besides, emerging topics of mobile technology and privacy issue was not discussed. Later study by Huang et al. (2017) analyses 141 publications between 2008 and 2014 to identify for paradigm shift brought the rise of social media, it was discovered that there has not been a research trend for social media in the field of PR (Alalwan et al., 2017;Huang et al., 2017;Khang et al., 2012).
Social media, from the perspective of PR executives, is an economical channel for carrying out marketing research and instant communications, organizations can use it for starting conversations and learning about market needs, customer profiles, strengthen and weaknesses of competitors, and their employees (DiStaso et al., 2011;Dwivedi et al., 2021). Major challenges facing organizations include change management affecting employees, especially for older employees need to adapt to the rapid technological changes, and the immediacy of the medium that required timely online service and crisis management (Khang et al., 2012). Augmented reality, virtual reality and artificial intelligence are typical examples of new technologies (Dwivedi et al., 2021). Moreover, there are risks of intellectual property leakages, criticism of the company or its management, fake news, user misbehavior, and brand damage caused by embarrassing employee behaviors (DiStaso et al., 2011;Dwivedi et al., 2021). Although faceto-face interactions have higher levels of social presence, virtual communicators like in social media can achieve certain level of intimate exchanges, and reinforce relationships through personalization of content (Kent & Li, 2020).

Four Models of Public Relations
The Four Models of Public Relations (FMPR) covers oneway and two-way communication (Grunig & Hunt, 1984). Public relations serve a promoting function in the first model: Press Agentry (PA), which involves in spreading preferred information by an organization. In Public Information (PI), the aim of PR is to report objective information to stakeholders. For the Two-Way Asymmetric (TWA) model, practitioners use researches and supporting figures to persuade stakeholders to accept the organization's opinion, as a result, gaining people's support. In the Two-Way Symmetric (TWS) model, public relations people serve as a middle man among organizations and stakeholders. Their purpose is to foster understanding among the organizations and the public. Regarding the nature of communication, for PA and PI models, they are always single way from the organization to the public. In the two-way asymmetric model, practitioners plan what they want to communicate to stakeholders for the purpose of achieving a change in attitude and behavior if possible. Communication from stakeholders is regarded as feedback only. Basically, TWA is still one-sided. A true dual communication model is the TWS. It consists of dialogs between the organizations and stakeholders. Stakeholders are likely to change organizational attitude and behavior whereas, at the same time, organization persuades people to change their attitude and behavior (Grunig & Hunt, 1984). Grunig and Hunt (1984) put forward the FMPR by combining several previous models with long history: PA from 1850, PI from 1900 Organizations that adopt PA equate PR with publicity or promotions, it is associated with propaganda, which is more commonly adopted in the business sector by companies which have departments specialized in advertising. PI is more frequently applied in government agencies, NGOs and educational sector for dissemination of information, expressed in active press-relations programs to spread news through media to the public. TWA is usually adopted by firms selling consumer products that are facing keen competition, this model stresses on positive reasons for taking the suggested actions using scientific persuasion. TWS are used by organizations that emphasize social responsibility, they organize dialog sessions to develop mutual understanding with recipients (Grunig & Grunig, 1992). Although there are tendencies for different types of organizations to adopt certain models, they need to consider the applicability of each model case by case, according to the kinds of problems that they are facing or the nature of public relations activities being carried out (Grunig & Hunt, 1984).

Criticism on the PR Models
Criticism received by the above mentioned models surrounded the dichotomous of symmetry/asymmetry and oneway/two-way communication dimension. Laskin (2009) considered FMPR theory more an academic concept and utopian normative ideal than a reflection of reality in PR, by claiming TWS to be the most effective mode of communication, the labeling of inferior models arouse resentment of PR practitioners (Laskin, 2009). Besides, some critical and post-modern theorists did not recognize TWS a final solution for creating truly equal participation and bringing benefit to all involved parties (Laskin, 2009). Due to the uneven distribution of resources between stakeholders and corporations, the unequal position provide chances for corporations to promote their own interests in power relations, therefore the seemingly symmetrical interactions are inherently asymmetrical (Stauber & Rampton, 1995). Cancel et al. (1997Cancel et al. ( , 1999 used "accommodation" in replacement of the symmetrical model, which refers to building trust with external publics through "dialog, compromise, collaboration, and cooperation." However, Grunig and Dozier (2003) argued that the notion of symmetry already underlines certain balance between organization and public.

Geographical Contextualization
Methods for measuring and evaluating in PR and CSR practices vary across geographical locations. Examples for PR frameworks such as GCS in the UK, DPRG/ICV from Germany, and some more internationally recognized model such as Barcelona Principles and AMEC Integrated Evaluation Framework (Buhmann et al., 2019). In Western countries, CSR is usually managed by PR practitioners. While in India, it is business executives and managers who lead CSR (Dhanesh, 2012). Multinational companies have to deal with PR in daily operation, likewise global NGOs also require communication officers to equip with sensitivity to multiple cultures and the ability to change while preserving core identity of organizations (Verčič, Zerfass, et al., 2015). In cross-cultural settings, even with English as the lingua franca, PR practitioners still have to balance between cultivate and nurture of mission and visions, and appreciate the diverse socio-economic, linguistic and political realities across continents (Verčič, Zerfass, et al., 2015).

Hypotheses Development
Engagement in social media is measured by users' behavior. Popularity can be measured by metrics, stakeholders' commitments and virality for engagements on Facebook (Bonsón Ponte & Ratkai, 2013). Popularity is gauged by reactions on posts, commitment refers to number of comments, and virality refers to the number of shares. This model assumed that the importance of Like, Share and Comment to be the same. In reality, the numbers of Likes, Shares, and Comments by fans when responding to feeds require different levels of efforts. Therefore, Cho et al. (2014) proposed the different levels of engagement was measured independently for the three Facebook engagement features of Like, Share, and Comment, such that the uniqueness of each these functions can be captured .
FMPR were also used for analysing organizational messages on Twitter (Waters & Jamal, 2011;Waters & Williams, 2011), and non-profit organization messages on Facebook (Cho et al., 2014;Nordström, 2012). The above studies showed NGOs tend to adopt public information model, and social media is generally used for communicating unilateral messages, while the provided interactive and dialogic functions have not been utilized fully (Waters & Jamal, 2011).
Social media usage is continuously evolving, it started as a private or social platform rather than for business supplementing their traditional marketing tactics. But nowadays, social media marketing becomes the dominant marketing strategy. It has been found that message structure in term of interactivity and formality could affect customer behavior (Dwivedi et al., 2021). Thus, it is a good timing to investigate NGO Facebook usage and examine the impact of different message strategies on stakeholder engagement as today. Two research questions are detailed as follows: Research Question 1: To what extent the FMPR is applicable to Hong Kong NGOs' Facebook usage? Research Question 2: "How do message strategies affect levels of stakeholder engagement on these NGOs' Facebook pages? (Wut & Yu, 2016, p

. 900)"
It is anticipated that when TWS model was used by NGOs, there could be more stakeholder engagement than when PA was used. "Like" is an affectively driven by sensory and visual features (Kim & Yang, 2017), which requires the minimum amount of effort, in comparison to typing text or emoticons in comments, and therefore being the most used button on Facebook for expressing positive attitudes such as agreement to the posted content. "H1: There is a significant difference in the lowest level of stakeholder engagement (Likes) among four types of organizational message strategies" (Wut & Yu, 2016, p. 900).
Among the three types of reactions mentioned, "Share" requires moderate level of effort, and it also expects responses from the others. Also, a shared post appears both on News feed and one's profile page. It might suggest "Share" post making some sort of one's presentation. "Share" could be regarded as cognitive behavior (Kim & Yang, 2017). It is the moderate level of engagement. "H2: There is a significant difference in the moderate level of stakeholder engagement (Shares) among four types of organizational message strategies" (Wut & Yu, 2016, p. 900). Replying to Facebook messages by making comments requires considerable cognitive effort, one creates or write a feedback indicates certain level of participation. It is the highest level of engagement compare to Like or Share, especially when more than one comments were involved. "H3: There is a significant difference in the moderate level of stakeholder engagement (Comments) among four types of organizational message strategies" (Wut & Yu, 2016, p. 900).

Sampling Process
The list of "Directory of Non-governmental Organizations" in Hong Kong was used as a sample frame (Hong Kong Non-Governmental Organisation, 2021). There are 434 non-governmental organizations. A simple random sampling method was used in the selection 20 NGOs which operate their official Facebook Fanpages targeting local audience. According to Wut and Yu (2016), Non-governmental Organizations can be classified into three categories, namely environment and animal welfare, healthcare, and service for people. Within the 30 days from 1 October to 31 October 2019, 443 posts have been uploaded on Facebook by these 20 NGOs. The data collected were organized in a spreadsheet with coding; the coded messages were later analyzed by statistical software, SPSS version 25 in January 2020. The sampling size is determined by point of saturation. Researcher tried to collect more samples beyond the said period but the result is basically the same.

Coding Procedure
For the content analysis of organizational message strategies, this study used the concept coding method. A concept is a word that suggests a meaning or an idea. In cases of messages involving multiple strategies, only primary strategy is being counted. Three levels of stakeholder engagement in terms of Likes, Shares, and Comments, of posts uploaded by the 20 NGOs were coded. Furthermore, followers for each of the organization's page, as well as the quantity of postings found in data collection period were recorded. Two independent coders carried out the coding process. The results obtained there from were compared. In case of any discrepancy, discussion between them was allowed before they came to a final conclusion. In case that the discrepancy is not resolved, a third coder was employed to examine the relevant posts and made the final decision. All the data were reviewed by two coders for reliability and validity.

Discussion of Findings
Among the 20 NGOs cover in this study, 10 belongs to environmental issues and animal welfare, 7 in human service, and 3 fall into the category of health. The number of posts in the October 2019 ranges from 1 to 89. The average number of post updated daily is 0.71. During the period set for date collection, the sampled post by these NGOs received 156,259 Likes, each post received an average of 352.73, ranging from 30 to 111,438.
Research question one examines the extent in which NGOs apply the FMPR on Facebook by frequency counts. Results show the least used model in FMPR was TWA (N = 13 posts or 2.93%; Table 1). Majority of messages under this model are with the purpose of event promotions, and stakeholder persuasion through raising awareness, asking them to offer help or to get involved in the organizations by taking immediate actions. PI was found to be the predominating model (N = 284 posts or 64.1%), followed by PA (N = 120 posts or 27.0%). NGOs mainly used PI model messages for updates and making announcements, and sometimes also for sharing reports or information published by other organizations, whereas PA model was used for expression of organizational emotions. The TWS model (N = 26 or 5.86%) messages usually appeared when cultivating dialogs, giving recognitions and expressing gratitude to donors, supporters, and/ or volunteers. Sometimes, hashtag function presence in the posts for easy searching by stakeholders on other posts under same topics.
Research question two investigates the effect of organizational communication strategies on the level of engagement on Facebook pages. One-way analysis of variance (ANOVA) test was adopted for hypotheses testing, which found differences between levels of stakeholder engagement in FMPR. ANOVA test analysis reveals considerable variations in the amount of Like (lowest level of engagement) between modes of FMPR (F = 8.091, p ≤ .001). Thus, H1 is supported. ANOVA test was designed to compare several means. Post hoc tests were used comparing all combinations of pairs of groups. The test is performed well when the group size is not much different. There are four models. Post hoc tests were used for comparing all combinations of pairs of groups. From the Post hoc tests with multiple comparison, Model 4, two-way symmetry model (TWS) has the greatest numbers of Like which is significant more than the rest of the models.  Table 2). Similar results were observed for the moderate level of engagement (Share) on messages regardless of which model is used (F = 0.378, p = .769). The p-value is not <.05, the null hypothesis cannot be rejected. Difference in the number of Comments (F = 0.303, p = .824) was insignificant. Thus, H2 and H3 were not supported.
The content analysis result parallels with the previous studies (Cho et al., 2014;Waters & Jamal, 2011;Waters & Williams, 2011;Wut & Yu, 2016), which suggest PI model to be the most popular among NGOs, followed by PA, TWS, and TWA, which means most NGOs used Facebook to promote activities and spread information. However, NGOs in Hong Kong seemingly engaged less with stakeholders on Facebook than their counterparts in western countries.
During the coding period, the average posts update rate is 0.71, which means that most organization publish two posts on their pages every 3 days. In order to maintain close communication with stakeholders on social media, organizations are supposed to provide frequent updates, while various studies pointed out that NGOs did not make full use of Facebook for stakeholder engagement . According to multiple scholars, lack of resources is an enduring challenge for NGOs in using digital marketing (Briones et al., 2011;Cho et al., 2014;Nordström, 2012;Pavlovic et al., 2014;Wut & Yu, 2016) as some of the organizations' followers might be attracted by other pages that are active and well-developed.
The study shows major difference in the lowest level of engagement (Like) in all of the four models, but the difference is insignificant for in the highest level of engagement (Comment), which did not align to the findings of Cho et al. (2014). Both studies found no significant divergence in the moderate level of engagement (Share) on all states of FMPR. Findings show that stakeholders were more willing to give Likes on TWS messages. Sometimes, NGOs use name tags to give recognition to supporters, fostering dialog, and address specific stakeholders. Even though PI used more frequently by NGOs, stakeholders were not commonly engaged by this type of messages.

Practical Implications
Some non-governmental organizations might not have enough budget for full fledge marketing programs. It is a trend that they tend to promote their campaigns through social media platforms more than before. It was found that those organizations were more likely to adopt Public Information (PI) model to transmit information to their stakeholders, in a style of similar to Web 1.0 (Cormode & Krishnamurthy, 2008). The direction of communication flow is one way, that is, toward the stakeholders. NGOs are the chief content providers and stakeholders simply acting as users of content. Also, it was found that they seldom engage actively with their followers or fans through constant update their page, which might affect their subsequent communication effects.
Online social networks are communities where people can share text, emojis, images, videos, and hyperlinks. Founded in 2004 by Mark Zuckerberg, Facebook was invented as private network for college students and later was expanded to include high school students. Stakeholders can use the instant messaging function to carry out real-time discussions enabled by a video tool. Since the age of Web 2.0, many tools are available to facilitate the potential for content creation (Cormode & Krishnamurthy, 2008), thus NGOs should investigate how to make better use of these social media platforms.
Incentives, membership, and past habit could affect online participation (Khansa et al., 2015). Thus, some goal settings for online users including labels and rewards should be used to enhance their participation. Changing the content on the social networking sites regularly and giving feedback to queries raised within a short time is necessary (Butler & Wang, 2012). It certainly increases the online traffic and user satisfaction.

Theoretical Implications
Apart from one-way and two-way communications in the "Four Models of Public Relations (FMPR)," multi-way communications are needed to add to Grunig and Hunt's (1984) framework in light of the digital era. Organizations cannot rely solely on Public Information model for spreading messages, communications among stakeholders are also important. Digital word-of-mouth generated on social media platforms is influential, because people tend to consider recommendations from their peers more than promotions from organizations. Thus the fifth model is named as multi-way (MW) model in multi-way communication mode, making use of communication among stakeholders.
Based on the Excellence Study with emphasis on mediation and orientation of conflicts; and establishing two-way communication to better describe the realities of PR practice, Murphy (1991) applied the game theory to incorporate both asymmetrical and symmetrical models into a multi-way communication model. The mixed-motive model acknowledges the importance of the organization interests while including a scale between TWA and TWS (Plowman, 1998). In this new model of symmetry, organizations and clients retain stronger sense of each other's interests, yet both parties are motivated to compromise in a limited extent in resolving conflicts (Dozier et al., 2013).

Limitations and Future Research
Facebook provide service that one could "buy" Likes from target audiences for sponsor posts (Kim & Yang, 2017). Our findings might not show the true behavior of respondents. It might be helpful for us to study stakeholder engagement using emoji, in which various small images, used to express the emotional attitude of the people without using text. Emoji is a non-text pictorial language used by more than 90% of social media users (Marengo et al., 2017), which is especially commonly used in mobile instant messaging to represent different emotions. Regarding its widespread usage, the effect of emoticons is worth for further research.
The number and categories of Non-governmental organizations could be increased to raise the representativeness of the samples. One month's data might not be enough to reflect the whole picture. Several years and cross-countries data could also be considered. The number of followers on a NGO's Facebook page could affect the effectiveness of stakeholders engagement as well. It would be a control variable.
Other message structure in terms of formality and immediacy might affect stakeholder involvement.

Conclusion
This study explored the Facebook usage of NGOs by analysing their social media adoption modes for stakeholder engagement. Confirming the results of previous studies, NGOs have the tendency to engage stakeholders with the one-way Public Information communication model. TWA and TWS communication models are not yet common practices even NGOs consider social networking sites ideal platforms to engage people with organizational messages.
For NGOs to make better use of the FMPR message strategies on Facebook, we suggest, firstly, at the earlier stage of founding a Facebook page, PA and PI strategies may draw the stakeholders to become followers. Several studies (Bonsón Ponte et al., 2015;Cho et al., 2014;Lovejoy & Saxton, 2012;Warren et al., 2014;Wut & Yu, 2016) believed information sharing "could be seen as a core activity to attract" social media users (Lovejoy & Saxton, 2012, p. 21). Secondly, TWA is recommended for engaging people in having further involvement. Finally, in order to achieve greater stakeholder engagement, TWS message strategy can be used (Cho et al., 2014).

Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work described in this paper was fully supported by a grant from Research Grant Council of the Hong Kong Special Administration Region, China (UGC/FDS24/B05/18).