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Safety: The consequences of user mistakes are usually reversible and have little, if any, adverse effect. The UI will incorporate standard keyboard shortcuts for undo and redo. The worst mistakes are probably accidental deletes and shares. The interface design accounts for this by making deleting and sharing hard to do by mistake. The "delete" button for a tower is at the bottom of the box for editing tower properties, and will be colored red. We may also choose to pop up a confirmation box, since deleting towers will probably not be a very frequent taskThe "reset" button also serves as a method of undoing changes.
Other considerations: The toolbars in this design may make the screen space cluttered and take space away from the visualization itself. However, in addition to the learnability and efficiency advantages, the use of toolbars makes the design highly extensible and customizable. The users can choose which toolbars to display based on which ones they use most frequently. Developers can also easily add functionality by adding a new toolbar, or adding to an existing one. The use of tabs also makes it easy for users to create multiple visualizations within the same project. The issue of displaying multiple visualizations at once is not addressed in the sketches above, but one possibility is to create multiple viewing panels, similar to the way many programming editors (Eclipse, Visual Studio) display multiple files at once. However, this method makes it difficult to decide what to do with toolbars. Another way is to drag one visualization onto another, e.g. drag a line graph onto the map such that the line graph takes up a smaller space in one corner. Then, toolbars by default will pertain to the main map, but the graph can be selected and edited using the same toolbars.
Design #2
The idea behind this design is to keep it very clean and simple. Manipulation is largely mouse-based and allows for a lot of real-time visual updates in response to the user's actions. The emphasis is on learnability. It should be intuitive for the user to move around the map, to choose and add layers, to select objects on the map to bring them into focus, to manipulate the time, etc. These actions should all map to actions that users are generally familiar with through other software and real-life activities. In addition, the focus on clean and simple design means that there are fewer aspects of the design for the user to learn. Efficiency may be sacrificed as a result, however, because in an effort to be minimal, certain things may be more than one click away, but the use of sliders for some functionality may help in that respect. As for safety, the user is fairly limited in their actions. They may accidentally add layers they don't want or change modes, but these errors are fairly simply undone.
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