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The colors of the marker correlates with the mood that each friend has set.
A mood must be chosen at login, but it can be changed at the top of the main page.
There are three moods: "Adventurous", "Relaxed", and "Studious." 
Friends can be organized into different groups. These groups are displayed as tabs in a sidebar on the right of the screen.
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Tamika is offline so she is not on the map. Mason is adventurous, which is represented as a red icon by his name in the sidebar and a red marker on the map. Xiaoji is relaxed, so her colors are blue. 
When the "Study Buddies" group is selected, Mason's marker becomes transparent, because he is not a member of that group. 
Groups are managed by the two bottom tabs. The "+" tab opens an add group dialog, and the "-" tab opens a delete group dialog.
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this method is simple, clear, and to the point.
IMPLEMENTATION
EVALUATION
Method
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Two of the users took significantly longer to complete the task "Create a group called Study Buddies" than any other task, and one user opted to be told how to do it. All three users commented that they thought the ' + ' and ' - ' signs meant that the buttons were meant for zoom functionality on the map. One user also commented that it did not help that the buttons were separated from the group tabs, as opposed to just being right below the last tab. This issue was acknowledged in pilot testing and originally deemed a cosmetic graphic design issue. However, the fact that our test users had significantly more trouble with the task, plus one user having to ask how to complete the task, we now consider this issue a major learnability issue. The solution to this issue remains the same as previously described in our pilot testing results.
REFLECTION
GroupsGroups