# User Perception of Facebook App Data Access: A Comparison of Methods and Privacy Concerns
## 3 Experimental Design
### Pre- and Post-Test Questionnaires
#### 3.1.1 Demographic and Background Questions
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Concer** & **Pre-test** & **Post-test** & **Change** \\  & **Avg.** & **Avg.** & & \\ \hline In general, how concerned are you about your privacy while you are using Facebook? & 3.533 & 3.925 & 0.392 & ** \\ _Are you concerned..._ & & & & \\ that Facebook will sell or release your personal information? & 3.483 & 3.833 & 0.350 & ** \\ that you are asked to grant access to too much personal information & 4.283 & 4.258 & -0.025 & \\ when you install a Facebook app? & & & & \\ about online identity theft via Facebook? & 2.867 & 3.508 & 0.642 & ** \\ about people you do not know obtaining personal information about you from your Facebook use? & 3.683 & 4.058 & 0.375 & ** \\ that content you post on Facebook may be seen by people other than those for whom you intended it? & 3.858 & 4.183 & 0.325 & ** \\ that a Facebook app could post to your timeline in your name? & 4.125 & 4.183 & 0.058 & \\ that a seemingly legitimate Facebook app may be fraudulent? & 3.833 & 4.042 & 0.208 & * \\ that Facebook apps could collect your personal data? & 4.058 & 4.158 & 0.100 & \\ that Facebook apps could sell your personal data? & 4.050 & 4.158 & 0.108 & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Answers pre- and post-test to questions about concern Facebook apps. Values are on a 5-point Likert scale ranging from “Not at all” (1) to “Very much” (5). Significant increases are marked * for \(p<\) 0.05 and ** for \(p<\) 0.01. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Question** & **Pre-test** & **Post-test** & **Change** \\ \hline _From what you know right now, when you install a Facebook app, do you think it has access to the following information?_ & & \\ Your personal information (name, gender, profile photo) & 98.3\% & 99.2\% & 0.8\% \\ Your friend list & 92.5\% & 95.8\% & 3.3\% \\ Your profile information (education and work history, relationship status, religion, _etc._) & 88.3\% & 91.7\% & 3.3\% \\ Your birthday & 90.8\% & 90.8\% & 0.0\% \\ Your likes (_i.e._, pages you like) & 85.0\% & 94.2\% & 9.2\% & * \\ Your status updates & 69.2\% & 85.0\% & 15.8\% & ** \\ Photos and videos you upload & 65.8\% & 88.3\% & 22.5\% & ** \\ Comments on your content (e.g., photos or status updates) & 62.5\% & 79.2\% & 16.7\% & ** \\ Your friends’ profile information & 66.7\% & 80.8\% & 14.2\% & ** \\ Your friends’ posts that appear on your news feed & 57.5\% & 85.8\% & 28.3\% & ** \\ Comments on your friends’ posts (from you and others) & 53.3\% & 72.5\% & 19.2\% & ** \\ Posts you made on your timeline & 74.2\% & 91.7\% & 17.5\% & ** \\ Comments on your timeline posts (by others) & 66.7\% & 85.0\% & 18.3\% & ** \\ Your current location & 82.5\% & 84.2\% & 1.7\% & \\ Your contact information (email, phone, address) & 85.0\% & 83.3\% & -1.7\% & \\ Your private messages to friends & 26.7\% & 40.0\% & 13.3\% & ** \\ Your chat logs & 23.3\% & 40.0\% & 16.7\% & ** \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Fact-based questions about information Facebook apps can access. The percentage of “yes” responses are shown. Significant increases are marked * for \(p<\) 0.05 and ** for \(p<\) 0.01. In Table 3, items highlighted in green can be accessed by all apps. Items highlighted in yellow can be accessed through extended permissions that the user cannot opt out of; _i.e._, if an app requests it, the user cannot install the app without granting permission. Items highlighted in pink can only be accessed through an optional opt-in extended permission request. Thus, we might expect some users to say apps cannot access certain data points, even if they know that apps can technically get them, because the users would choose to deny access.