# User Perception of Facebook App Data Access: A Comparison of Methods and Privacy Concerns
## 4 Results
### Overall User Understanding of Privacy Risks  
The results in Table 2 show subjects' opinions about Facebook apps' access rights before and after viewing the information. On average, subjects generally believed the basic information was accessible more than the non-optional extended permission data, and both were available more than the optional extended permission data. That said, even for the basic information that all apps can access, we did not see 100% of users believing that apps could access it, even after viewing the information in the conditions that clearly indicated what was given to apps. For the non-optional extended permission data, which any app can request access to and for which users cannot deny permission (except by refusing to install the app), we saw significant increases in the percentage of users who believed apps could access this data. However, few of these saw over 90% of users believing apps could access the data, let alone 100% of users. Figure 3: The interface of the Facebook Data App. Finally, for the most private data (accessible to apps, but only through extended permission requests that the user can deny), a high percentage of users believed contact information was made available to apps. Many fewer users believed chat logs and messages (both of which reside in a user's Facebook inbox) were accessible. It is possible that some users would say this information is inaccessible since they would personally deny access to apps that requested it. It is also possible that the way in which apps can get to this information is not made clear by any of the privacy information sources. Looking at all of these data points, we see that users are under-informed about what information apps can access, and though education about the data access permissions can help, users still underestimate the amount of information that apps can access. This, in turn, has implications for how they make decisions. We discuss this further below. We then divided subjects into two groups: those who report using Facebook apps to those who report not using them. Forty-eight subjects claimed to not use apps (\"non-users\"), while 71 do use them (\"app users\"). Non-users were significantly* more likely than app users to believe that apps could access Status Updates, photos, a user's content and comments, newsfeed data, comments on friends' posts, timeline posts, and others' comments on timeline posts. This data is shown in Table 4. This shows that people who are using apps are generally quite under-informed about what personal information they are handing over. Among app users, post-test perception about what data Facebook can access significantly increased** for nearly all items: accessing likes, photos, content and comments, friend lists, friend information, newsfeed data, private messages, chat logs, comments on friends' posts, timeline posts, and timeline comments. For non-app users, concern increased regarding apps accessing status updates**, photos**, chat logs**, and timeline posts**. We also hypothesized that pre-existing concern about privacy might influence the results. We applied the Westin/Harris Privacy Segmentation Model described above and found our sample contained 31 Privacy Fundamentalists, 88 Privacy Pragmatists, and no Privacy Unconcerned subjects. Not surprisingly, Fundamentalists started out with more overall concern about privacy on Facebook compared with Pragmatists (3.935 _vs._ 3.375*), concern that Facebook would sell their data (3.935 _vs._ 3.307*) and that unintended users would see their data (4.27 _vs._ 3.7*). In the pre-test, significantly* more Fundamentalists than Pragmatists believed apps could access their content and comments, friends' information, newsfeed, private messages, and contact information. In the post-test survey, fundamentalists saw no significant changes in their concerns or beliefs about what data apps could access, while Pragmatists saw significant increases in 17 out of 27 survey questions.