# SNUXH: A Set of Social Network User Experience Heuristics
## 5 Validation of SNUXH
### Third Iteration: Validation through User Tests and Expert Opinion  
In the third iteration, we performed a Co-discovery test to evaluate Facebook (in its 210-240 version). Co-discovery is a user testing method that offers valuable user thinking/thoughts insides [30]. Users explored Facebook in pairs, freely discussing it, while performing together predefined tasks. A total of eight users participated in the test forming four groups (two users per group). Participants \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Heuristic** & **D1—Utility** & **D2—Clarity** & **D3—Ease of Use** & **D4—N. of Add. Elem.** \\ \hline SNWH1: Visibility of elements and system status & 4.25 & 4.5 & 4.5 & 4 \\ SNWH2: Perception and user status & 4.5 & 4.25 & 4.5 & 3.5 \\ SNWH3: Match & & & & \\ between system and & 4 & 3.25 & 3.25 & 3.75 \\ the real world & & & & \\ SNWH4: Consistency and standards between & 4.5 & 4 & 4.25 & 3.5 \\ system elements & & & & \\ SNWH5: User control & 4.5 & 4.5 & 4.25 & 3.5 \\ and freedom & & & & \\ SNWH6: Error prevention & 4.25 & 4 & 4 & 3.75 \\ SNWH7: Minimize the user’s memory load & 3.5 & 3 & 4 & 4.5 \\ SNWH8: Flexibility and efficiency of use & 4 & 3.25 & 3.5 & 2.75 \\ SNWH9: Aesthetic & 4 & 3 & 3.75 & 4 \\ SNWH10: Help user to recognize, diagnose, and recover from errors & 4.5 & 4.25 & 4 & 3.25 \\ SNWH11: Help and documentation & 4.5 & 4.5 & 4 & 3.5 \\ SNWH12: Privacy and exposure control & 4.25 & 4.25 & 4 & 4.75 \\ SNWH13: Content control published & 4.25 & 3.25 & 3.25 & 5 \\ SNWH14: Security and recovery of user & 4.5 & 4.25 & 3.75 & 3.75 \\ account & & & & \\ Average & 4.25 & 3.88 & 3.93 & 3.82 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Average perception scores for SNWH are set in the four evaluated dimensions (second iteration). were undergraduate students of 21-26 years old, from the Computer Science program at Pontificia Universidad Catolica de Valparaiso (PUCV), Chile. All participants have experience using social networks and Facebook. The experiment was designed to validate that the usability/UX problems identified in the heuristic evaluation (first iteration) are perceived as real problems for the users, and to identify new problems and review if these problems are evaluated by the SNXH set. The test was divided into three parts: (1) A pre-experiment questionnaire, aimed to broadly identify user's profile and his/her previous experience using Facebook; (2) a list of tasks to complete working in pairs (the experiment); and (3) a post-experiment satisfaction questionnaire, aimed to know the user's perception using Facebook. We included questions concerning users' perceptions about task completion, orientation through the website, overall satisfaction regarding Facebook, and intention of future use. We also included open questions that allowed users to comment on Facebook's (perceived) positive and negative aspects. Table 5 shows the tasks performed by the users in the Co-discovery test and its results. The results of the questions asked were not included because the responses received were not significant to generate additional changes. Based on the results, shown in Table 5, we concluded that the problems P1, P2, P3, P5, P6, and P10 are perceived as real problems for users since it was difficult for the groups complete the related tasks. We reviewed if SNXH allows evaluating the usability/UX problems detected in the test. As shown in Table 5, all problems detected in the Co-discovery test are covered by SNXH, except the problems P3 and P8, which means that it is necessary to create a new heuristic that evaluates the intuitive use of elements that do not confuse the user. We also conducted an expert opinion for validating SNXH. We asked two experts in HCI what they think about the SNXH set. The experts had experience performing heuristic evaluations and using sets of usability/UX heuristics. They gave their points of view regarding whether the SNXH set is correctly specified, whether it is useful, what elements they would add or remove.