Escape

Validation level: 5. CHI, UIST, CSCW and TOCHI paper publication

Escape is a gestural technique for selecting occluded items in crowded maps. This technique is meant for touchable screens of limited size. Each item is represented by a dot with a beak pointing to a cardinal direction (South, West, North, East, South-West, South-East, North-West or North-East). For selecting the item, the user will touch the item and drag the finger to the direction indicated in order to select it.

Mobile phone Touch screen Map Occlusion Selection Gesture
Publications
Copy Bibtex Vogel, D. and Baudisch, P. Shift: A Technique for Operating Pen-based Interfaces Using Touch. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, pages 657-666, ACM, New York, NY, USA, CHI '07 , 2007.
Also featured in
Storyboard of Functions

The user clicks on the item that wants to select. As it is a crowded map, there are more items in the same place.

The user drags the finger to the East to select a certain item, that has the beak at the right.

When the user ends the gesture, the item is selected.

Evaluation
Performance Time and Error rate of Escape technique and actual Shift technique for selecting items taking into account different levels of occlusion.
Evaluation
Comparison of performance time between Escape technique and Vogel's shift technique taking into account the size of the items.
Evaluation
Performance time of the task depending if the beak of the item is occluded or not.
Evaluation
Performance time taking into account the occlusion of the item and the colour representation of each item (if every direction is represented with a different colour, or all of them with the same).
Evaluation
The error rate of the task depending on the direction of the beak.
Highlights:

Selection of occluded objects in crowded maps with a simple touch gesture. What differentiates this technique to other ones already proposed, as the Shift technique of Vogel listed in the Related Work section, is the improved time performance.

Limitations:
  • As the technique needs most of the screen for the target selection, there is less space in the screen for implementing other functions.
  • It allows less number of items on-screen that other proposed techniques, as Shift technique.
  • The items around the borders of the screen have fewer options for the directions than the ones in the middle of the screen.