4 What Determinants Matter When Users Engage in Particular Collaborative Storytelling Websites? Exploring Attractive Gamification Features and Design Guidelines

: Gamification refers to the incorporation of game mechanics into non-game settings, which aims to increase user’s engagement with the product or service and facilitate certain behaviors. Gamification receives considerable attention for various social networking services and product design. Specifically, gamification is considered as the predictor of the user’s engagement with collaborative storytelling websites. Although previous studies have mentioned a broad range of factors that may influence gamification, they neither depicted the actual design features nor relative attractiveness among them. In line with this, the present aims to identify attractive gamification features for collaborative storytelling websites. We first constructed a hierarchical system structure of gamification design for collaborative storytelling websites and conducted a focus group interview with eighteen frequent users to identify 35 gamification features. Following this, the relative attractiveness of these gamification features was determined by administrating an online survey to 6333 collaborative storytelling websites users. The results indicated that the top 10 most attractive gamification features could account for more than 50% of attractiveness among these 35 gamification features. The feature of unpredictable time pressure is important to website users, yet was not revealed in previous studies. Based on these findings a number of design guidelines were created for gamification in collaborative storytelling websites.


Introduction
][3] At present popular collaborative storytelling websites such as Protagonize.com,Storybird.com,and Flickspin.comalways attract myriads of users to discuss and collaborate on stories online.In collaborative storytelling websites, users can not only work together in teams to create collaborative stories but also feed off of each other's ideas, devising more creative stories together.Importantly, collaborative storytelling websites have educational potential by providing story materials and support to help users develop interpersonal and story-related skills through Introduction organizing, communicating, evaluating, and transforming life experience into words. 2Moreover, collaborative storytelling websites provide connection with other social networking services such as instant messengers, Facebook, and Twitter, which not only amplify its social influence between users, but facilitate more user to user interactions and negotiations. 4Thus, collaborative storytelling websites have received considerable attention from both educators and internet researchers.
Some studies have considered gamification design as one critical factor that contributes to the success of collaborative storytelling websites because of its fun and interactivity. 5,6 he definition of gamification refers to the incorporation of game mechanics into non-game settings, which aims to increase user's engagement with the product or service and facilitate certain behaviors. 7Recently, gamification is widely used for increasing user's interaction and engagement in a variety of domains such as business and marketing, 8 health and wellness, 9 education and training, 7 corporate and vocational training, 10 as well as public policy and the government. 10So far collaborative storytelling websites effectively attract and maintain users via various gamification designs, such as leaderboards and badges. 7Moreover, the gamification features attract uses by providing fun and flow experience as users create and collaborate on stories together, which result in more daily users and higher average time spent on sites. 5Gamification essentially functions as entertainment which makes collaborative storytelling website users enjoy actively participating and engaging with others.Consequently, gamification plays a critical role in the survival of collaborative storytelling sites.
Prior studies have been conducted to identify the influences of gamification.8][19] While aforementioned studies have mentioned a broad range of factors that may influence gamification, these studies depicted neither the actual design features (design guidelines) nor relative attractiveness of them.Identifying the attractive design features for gamification could establish significant milestones in how to make attractive collaborative storytelling websites.
This study aims to identify gamification features for collaborative storytelling websites.Following this, the relative attractiveness of these gamification features will be examined.Doing so would help website developers focus on those aspects with the greatest weight and identify the best design strategy for improving websites' attractiveness through gamification.

Systematic framework of gamification design
In this study, we first attempted to construct a hierarchical model to represent the systematic structure of gamification design.After reviewing gamification factors from relevant literatures, we then conducted a discussion with four website designers on these factors and corresponding design mechanics for collaborative storytelling websites.Therefore, through this process, some factors may be excluded because they are lacking corresponding design mechanics for collaborative storytelling websites.All gamification factors discussed in this study can be divided into three main components: achievement, interpersonal relationship, and role-playing.8][19] The role and user are not only closely interconnected with each other but also allow users to accomplish their goals at the personal and social levels.Various sets of gamification features associated with each design factor in the second level are linked to the third level.The hierarchical framework of gamification design in this study is shown in

Achievement
Rewards.Rewards refer to the gamification factors that satisfies users shared need and motivates them to implement certain behaviors. 10,17 or example, users are motivated to create more stories with others in order to receive more and more rewards from websites.At present, gamification design mechanics of rewards includes tangible reward (i.e. points or virtual currency) and intangible rewards (praise or recognition from others) that users can see and use to benefit themselves. 10The rewards mechanism operates in terms of earning points or the equivalent (like frequent-flyer miles) and effectively forms a reward-behavior cycle. 19That is, the more time a user invests in the expected behaviors, the more rewards they will receive from websites.
Goal setting.Goal setting is related to the most motivating goals that are just out of comfortable reach. 20Users always conduct certain behaviors toward a specified goal because the fun and interest of goal seeking is often the primary reward itself. 21In the context of collaborative storytelling websites, user's goals may comprise personal level goals (i.e.individual achievement and learning) or group level goals (i.e. group achievement and belonging).So far the gamification design mechanics of goal setting mainly operates in two ways, explicit signs (i.e.trophies and badges) and progress towards goals (i.e.progress bars or percentage). 10eputation.2][23] The idea of a reputation has been widely adopted by online shopping websites, such as eBay and Amazon.com, to increase the reliability of systems, reduce risks between users, and help users decide whether to interact with other users based on the experiences of third-party users.In the setting of collaborative storytelling websites, reputation can be seen as an effective tool for determining the trustworthiness of users or the reliability of story.For the moment gamification design mechanics of reputation include special titles or highlighted personal profiles within the community. 7tatus.As users join a social group, status refers to the user's need for recognition, fame, prestige, attention, and other user's respect. 10,21 tatus serves as user's desire to be recognized and foster users to achieve goals enthusiastically.For collaborative storytelling websites, the status also represents user's contribution on creating stories and participating in websites' activities.A quantified approach is often used for representing design mechanics about user's status, such as experience points and level-up. 10

Interpersonal relationship
Instruction.As new users (also called newbies) enter into a system, some instructions are required to teach them the social norms. 21,24 nstruction not only functions as the social shaping of user activities but also assists users in mastering the whole system in an efficient way.In the context of collaborative storytelling websites,instruction helps users to learn communication and teamwork skills as they collaborate with others."Nonce helper" and billboard is usually used for representing the gamification mechanics of instruction in collaborative storytelling websites. 3ompetition.Competition refers to the user's desire to compete with others, including reaching high scores in order to defeat others, with the winning user receiving a prize or benefit. 10,11 hus, users enjoy the striving for the advantages of winning and will go on competing with others.The gamification design mechanics of competition is leaderboards, which lists winners among all competitors. 10ltruism.Altruism is user's desire to bridge and maintain relationships with others through conducting certain behaviors, such as gift-giving or ask for help 10,21 .Trivers 25 has suggested altruism to be the user's desire to conduct reciprocal behaviors with others on the basis of trust.Altruists indirectly contribute to their fitness through reciprocation with others. 10In the context of collaborative storytelling websites, support for gift-giving and charity are the most popular altruistic behaviours.Specifically, altruism is also considered as a strategy to attract new users. 10,21 or instance, users may receive a gift from someone that pulls them into the game, and then they're incented to send gifts to friends, eventually creating a acquisition loop.

Role-playing
Group identification.][28] Users with higher group identification are often willing to remain in group permanently and to strive toward the goals, obey the guild managers' commands, and devote themselves to group affairs. 29At present the gamification design mechanics of collaborative storytelling websites are self-organized quest teams or members' family.
Self-expression.Self-expression refers to users' desire to express their autonomy and originality, which shapes their unique personalities. 10,21 ser's self-expression involves the user's feeling of social toleration, life satisfaction, public expression, and an aspiration to liberty.Gee 30 conducted a study on digital game based learning, also considered assisting users to build their self-identity in virtual world can facilitate user' involvement.To show off user's uniqueness on collaborative storytelling websites, the gamification design mechanics of self-expression are virtual goods, spaces, and avatars. 10,19 me pressure.Time pressure means giving users time limits to conduct certain behaviors in order to encourage them to interact heavily during this period 5,21 .For users, creating time pressure can produce more emotional feedback and encourage greater participation as the time pressure is connected to their goals.For example, some mobile applications set a 5 second time limit to find the targets, which encourages the user to interact with application heavily during this period.As a player fails, a new game automatically starts 5 seconds later.The gamification design mechanics of collaborative storytelling websites employed to create a sense of time pressure include countdown timers, time bars, and check points. 10

Identifying gamification features for collaborative storytelling websites
A focus group interview was conducted with the purpose of identifying the gamification features of collaborative storytelling websites.Materials, subjects, and results of interview are described below.

Materials
Three websites including Protagonize.com,Storybird.com,and Flickspin.comwere used in this study.These three websites are representative collaborative storytelling service providers, with a myriads of users worldwide.

Participants and Procedures
The survey was advertised on several strorytelling forums to recruit volunteers to participate.Eighteen experts, consisting of nine male and nine female story website users, were selected for the interview.All of them are frequent story creators and have at least five years story writing experience.All users were asked to identify and discuss gamification features based on the proposed systematic gamification framework..

Results
To improve the features, three human-computer interaction experts were invited to examine the framework.These experts reviewed all features of the framework, considering the significance and rationality.Finally, thirty-five gamification features were developed following the in-depth interviews, as shown in Appendix 1.

Determining the relative attractiveness of gamification features
This study asked collaborative storytelling website users to identify the 35 proposed gamification features.Following this, a fuzzy-AHP methodology was applied to determine the relative attractiveness of the various gamfication features.

Questionnaire design and data collection
A questionnaire was developed for the present study to gather collaborative storytelling website user's assessments of the relative attractiveness of the different gamification features in a pair-wise comparison data input format based on the hierarchical structure (see Fig. 1) and gamification features described above.The questionnaire used a nine-point rating scale which assessed therelative attractiveness of each gamification feature, for example, as equally attractive, moderately attractive, strongly attractive, very strongly attractive and extremely attractive, as suggested by Saaty 31 (see Appendix 2 for an example of the Fuzzy AHP questionnaire).To validate the instrument, the questionnaire was first pilot tested with thirty evaluators.All evaluators had more than 3 years' experience using collaborative story telling websites.They were asked to comment on the relevance, clarity, and meaningfulness of the criteria.Therefore, the questionnaire has confirmed content validity.After this we administered the questionnaire through an internet survey and recruited 6333 users who had used collaborative storytelling websites.After primary data analysis, we deleted incomplete questionnaires and outlier data, leaving us with 5566 valid samples (87.9 %) for use in this study.The gender distribution of participants was 2639 (47.4%) males and 2927 (52.6%) females.The age range was included 21-30 (34.7%), 31-40 (39.2%), 41-50 (10.6%), 51-60 (10.1%), 61 and above (5.4%).Additionally, 12.7% of the same had experience using collaborative storytelling websites for less than a year, 31.4% had experience for 1-2 years, and 55.9 % had experience of more than two years.

Data Analysis
There were seven steps in our proposed fuzzy-AHP approach.We first used triangular fuzzy numbers to construct the fuzzy comparison matrix.Second, we integrated the collected user's assessments of each gamification features design factor and design components using the fuzzy average method proposed by Buckley 32 .Third, we computed the fuzzy weight of each gamification feature using the Approximation Method introduced by Buckley 32 .Fourth, the Center of Gravity Method, a defuzzifying method proposed by Tzeng and Teng 33 , was performed to defuzzify the weight of each gamification feature.Fifth, we normalized the weights of all gamification features.Sixth, we aggregated each level of the proposed gamification framework and calculated the relative attractive value of the fuzzy weight for each feature at factor levels.Finally, we computed the consistency index (CI) and consistency ratio (CR) for each fuzzy comparison matrix.The detailed process of data collection and the proposed fuzzy-AHP model are described in Appendix 3.

Results
Among the 35 fun gamification features, the top 10 most attractive features, listed in Table 1, account for more than 50% (57.47%) of gamification attractiveness.

General Discussion
For the purpose of this chapter, the top five attractive gamification features are discussed below.The most attractive gamification feature is "the relationship between action and reward is clear".It means the collaborative storytelling website users pay more attention to feedback after conducting certain behaviors.Users prefer to know the immediate consequences of his or her behavior.It also reflects the websites' need to assist users map their behaviors with rewards intuitively.This finding is consistent with previous studies.Norman 34 considers that natural mapping provides users with immediate feedback on their controls because it reduces user's effort and memory load.In addition, Ducheneaut and Moore 18 , conducted a survey on Massively Multiplayer Role-Playing Games (MMORPGs), finding that a clear relationship between action and rewards can foster user's motivation, and drive users to engage in activities more.
The second most attractive gamification feature is that "the types of time pressure are unpredictable".This gamification feature makes users involved because they have to respond to various unexpected events within a collaborative storytelling website.The feature may be related to challenge, which is a basic intrinsic motivation of users.Users may be attracted by the challenges proposed by unpredictable time pressure.Surprisingly, this finding has not been revealed in the previous literature.
The third most attractive gamification feature is "instruction is easy to learn," which means that users emphasize the learnability or usability of websites' instructions.This finding is consistent with Crawford's study, 35 which found that good instructions enable users to master the system effectively, which increases their involvement.
"Building groups with other users to accomplish a story is helpful " is the fourth most attractive gamification feature.This feature reflects users need to be socialized or affiliated with groups as they write stories online.This finding is consistent with Gee's research, which stated that users constitute an "affinity group," in which they work together under the same goals . 30Moreover, Hsu et al. ( 2009) also found that selforganized groups will form experience social bonding effect, which increase user's engagement with activities.
Finally, "Badge types are diverse and interesting" is the fifth most attractive feature, which suggests that players are attracted by badges and enjoy attempting to collect all of them.This finding is also consistent with previous studies.Law and his colleagues 36 , conducted a study on the relationship between gamification and sustainability of mobile applications, and proposed that badge collection is an important enhancer of user's involvement.As users enjoy collecting different kinds of badges, they are more likely to engage in using mobile applications.

Design guideline for implementing gamification in collaborative story telling websites
The gamification features introduced in this study present some of the most attractiveness elements for users.Based on these features, the following guidelines were designed to enable website owners to attract more users.
Encourage social events and group activities Websites could display information regarding upcoming social events or invitations to group activities as users log onto websites.Increased participation in social events translates into higher user engagement with the website.
Build rapid feedback cycles for users -To improve usability, providing immediate feedback facilitiates users progressing to new tasks and new skill levels.Especially for new comers, websites should give users direct feedback as instructions in order to to assists in improving their story writing skills.
Adjust in-website tasks to skill levels Like computer games always attract users since it allow users foreseen the success of game, website designers should design tasks with different levels adapted to user's different skill levels.Challenging tasks increase user's likelihood of stay longer, as opposed to frustrating tasks.
Assist users to improve their skills through social incentives Users can receive recognition for writing achievements by peers helping users to develop their identity on the website.Social recognition also motivates users to improve their skills.
Motivate users to give others' reward or social recognition In the game World of Warcraft (WoW), player groups often use a special scoring system called Dragon Kill Point (DKP) for promoting collaboration among members.DKP provides transparent information of each member's task allocation and involvement, which is the same as groupware in the real-world setting.In collaborative storytelling websites, users can get recognition and rewards for their participation with storytelling activities.Users also have to learn to reward other users in order to promote social bonding and a sense of belonging between user groups.
Enable website users to try as many new identities and roles as possible In most online games, players can assume different identities and perform different roles.In collaborative storytelling websites, users can also be allowed to try different sides of themselves and gain a more immersive experience.
Encourage mutual competition among users to facilitate valuable behaviors Website designers can design various challenges tailored to the user's level of writing skill, increasing the difficulty of these challenges as the users acquires new skills.Challenging tasks are also more fun for users and increase their engagement with the website.

Conclusion
This study aimed to identify attractive gamification features in the context of collaborative storytelling websites.Using an empirical method we propose 35 attractive gamification features of collaborative storytelling websites.Among these attractive gamification features, the feature of "the types of time pressure is unpredictable", was identified and was not yet revealed by previous studies.A reasonable explanation may be that users tend to enjoy something which is challenging and immerse.
This research has both theoretical and practical contributions.From a theoretical standpoint, this study presented a systematic framework for studying gamification in collaborative storytelling websites or similar environments.This study not only confirms but also extends the current line of research on gamification.
On the practical side, the findings can serve as a reference framework to assist in the design and development of collaborative storytelling.Also, the questionnaire used in the study can also be employed to evaluate attractiveness of specific gamification dimensions to improve their function and design.
Limitations of this research should be noted.We do not suggest that the factors we have discussed represent an exhaustive list, in that other possible gamification factors may not have been included in this study.

Areas for Future Research
Future research may wish to use different methodologies, such as longitudinal studies, focus groups, and ethnography approachs to identify other gamification factors for collaborative storytelling websites.~ were employed to represent the results of users' assessments of the pair-wise comparisons between each of the design features (see Table 1) by constructing a fuzzy positive reciprocal matrix M. The proposed fuzzy comparison matrix was defined as follows:

APPENDIX 2. A FUZZY-AHP APPROACH FOR DETERMINING RELATIVE ATTRAC-TIVENESS OF COLLABORATIVE STORYTELLING GAMIFICATION FEATURES
M: fuzzy positive reciprocal matrix L ij : the left value of the fuzzy membership function of the collected subject assessments of design feature j of decision element i M ij : the middle value of the fuzzy membership function of the collected subject assessments of design feature j of decision element i R i : the right value of the fuzzy membership function of the collected subject assessments of design feature j of decision element i Step 2. Integration of the collected subjects' assessments of each decision element There are many possible approaches to integrating subject assessments when calculating the triangular fuzzy number.In contrast to some studies that apply statistical parameters such as the minimum, maximum, mean, and mode to represent the fuzzy numbers, this study applied the geometric mean method proposed by Buckley [59].The computing process is defined as follows: : Integrated triangular fuzzy numbers : The value of the pair comparison of the collected subject assessments of design feature j of decision factor i n: The number of subjects We then used the Center of Gravity Method of defuzzification to calculate the center of gravity of the triangular fuzzy number.Given a triangular fuzzy number and its three sides, denoted by Ã= (L ij , M ij , R ij ), the defuzzified weight DF ij was calculated using the following formula:

Figure 4 . 1
Figure 4.1 Hierarchical system structure of gamification of collaborative story telling websites

Step 1 .
Constructing the fuzzy comparison matrix Triangular fuzzy numbers ij M ~ from 1 ~to 9

Table 1 .
Membership function and definitions of fuzzy numbers

Step 3 . 4 .
Computation of fuzzy weight After integrating the collected data and calculating the corresponding triangular fuzzy numbers, we used the Approximation Method proposed by Buckley [59] to compute the fuzzy weight.The formula of the Approximation Method for computing the fuzzy weights is defined as follows: : The geometric mean value of the triangular fuzzy number : The triangular fuzzy number of row i and column j in the fuzzy positive reciprocal matrix : The fuzzy weight of each row of the fuzzy positive reciprocal matrixStep Defuzzification of decision elements The weights of the decision elements were represented by fuzzy values.The defuzzification process assigned a distinct number to each of the decision elements.