However, portable touchscreen devices such as the iPad (tablets) still have a very fundamental deficiency when it comes to human-computer interaction; feedback. Most touchscreen devices such as the iPad, Samsung's Galaxy Tab, and most touchscreen cellphones have implemented vibrating feedback, so when the device will vibrate when the touchscreen receives input. This type of feedback works in a very basic “Vibration-No vibration” manner. This neglects what is perhaps our most strong sense. The sense of touch can perceive a very wide range of sensations of very wide magnitudes, and these devices do not take advantage of the fact that “the sense of touch can be used as a high-bandwidth communications channel.” If we review other tools in humanity, we can notice that they have in a way, and perhaps unintentionally, provided feedback. The weight of a hammer, and the way it vibrates when it's used to hammer a nail provided plenty of feedback information regarding the strength was used, whether or not it was enough to nail the nail down, and if there may be a harder layer under the surface the nail may not go thru. When computers were invented, this feedback was also present in some way; the feeling of a key being pressed down, a finger being able to feel gaps between keys, the friction between the mouse and the desk, etc. Haptic feedback, in an ironic way, is meant to make human computer interaction more intuitive by using the sense of touch, but it seems to neglect it more than most conventional input systems. The following chart displays the relation between haptic feedback, visual feedback, and input errors commited by the user:

===Conclusion===