In this design, we have three displays — displays in the elevator lobby (about 30” x 15” each) that will allow users to indicate what floor they want to go to, one display beside each elevator (1ft x 5ft) showing what floors the elevator will stop on and how long it will take the elevator to arrive, and also a display inside the elevator to indicate how long it will take the elevator to reach a certain floor and also which floors it will stop on.
Displays in elevator lobby
The displays in the elevator lobby will be scattered among the elevators in the area. Each display will give the user a way to indicate the floor they want an elevator to stop at. The display will also show the elevator that is assigned to stop at that floor on a map showing the layout of the elevators in the lobby and also how long it will take for that elevator to arrive. This display is impaired vision friendly since those with impaired vision can still easily indicate their floor without needing to feel around for Braille or learn the positions of buttons; also there is a speaker so that a visually impaired person can still figure out how to get to his or her appropriate elevator.
Learnability: The learnability of this display is important since users will need to know how to indicate their desired floor before being able to use the elevator. Also, these areas are usually very heavily trafficked, and causing a huge traffic jam is not ideal. The learnability of the map that indicates where the target elevator is in the lobby is pretty obvious. Because the target elevator is highlighted and the desired floor number shows up on the corresponding elevator icon, it should be obvious which elevator is the one a rider must head towards.
The right side of this screen is a little less learnable. Using the top half (where a user can write out with their finger which floor they wish to stop on) is best learned by watching others use the feature. The bottom half is used to type out a desired floor. The typed out result shows up in the top half. The buttons in the bottom half have to be arranged and colored in a way so that it is obvious that the buttons are used to type in a floor number and not for some other purpose. It must be laid out in a way that does not resemble another common function.
Efficiency: This display is pretty efficient. The map on the left is easy to read and understand once the user has made an association with the map and physical location for the first time.
Safety: The interface for inputting a desired floor is okay at preventing errors, and it provides ways to recover from errors when users input their desired floors. On the right side of the screen where users have two options for entering their desired target location, there is a clear button. The clear button is somewhat close to the submit button, and the rate of error for pushing the wrong button will have to be investigated in user testing.
Regarding the left side of the screen, if a user doesn’t pay attention to the left side of the screen after they click submit on the right, they could miss which elevator they’re supposed to use. This This makes the design not very safe; however, because of the other displays, it is easy to recover (also, a user can just input the same floor again into the right side of the screen).
Displays next to each elevator
These displays are next to each elevator. These displays show the floors that the elevator will stop at, where the elevator is currently, and also the time when the elevator is expected to arrive. This is meant to be used for when a user is walking towards it and wants to make sure he or she is going towards the correct elevator and also that he or she has enough time to get to that elevator. This is also used when users are standing and waiting for an elevator to arrive — the display will show the estimated time of arrival.
Learnability: This display is relatively learnable because of how it exhibits external consistency. The strip on the left that shows how the elevator is moving up and down mirrors how an elevator moves through floors in a building.
Efficiency: This method of showing where an elevator is in a building is efficient since the floors are ordered naturally. Users who are looking for an elevator that will take them to their desired floor can more easily find their target floor since the floors are in order. This is efficient to use since users are used to seeing the same display inside the elevator.
Safety: The users have no control over this interface, so safety is not an issue.
Displays inside each elevator
These displays are located in each elevator and are meant to show the location of the elevator and the time needed to reach each floor that the elevator is scheduled to stop on. There is also an emergency button that can be pressed to stop the elevator at the closest floor. Pressing the button will trigger a loud noise to discourage people from abusing the button.
Learnability: The displays on the inside of the elevator should be pretty easily learnable because it is consistent with the display that is next to the outside of each elevator. Like the display outside each elevator, this interface exhibits external consistency. The interface provides essentially the same information and is portrayed in the same way. The only difference between the display outside the elevator and this one is the very top of the display. In this display, the floor that the elevator is stopping at next is the main focus — these values scroll through as the elevator moves up and down.
Efficiency: This method of showing where an elevator is in a building is efficient since the floors are ordered naturally. Users who are looking for an elevator that will take them to their desired floor can more easily find their target floor since the floors are in order. This is efficient to use since users are used to seeing the same display outside each elevator.
Safety: Other than with the emergency stop button, the users have no control over this interface, so for the most part safety is not an issue. We did not provide a way to recover from accidentally pushing the emergency stop button since the risk of accidentally shutting off the emergency stop button in a real accident would be a bigger problem than just the inconvenience of an accidental false alarm.