**5. Touch screen in the next generation Classroom Response System (CRS)**

As we explained earlier, optical touch screen described in this article is simple to implement, inexpensive to equip, and not sensitive to the wear and tear due to the pointers scratching on the touch screen. A commercial version of this device can be used to superimpose but not obstruct the existing writing surface. This makes it ideal to be used on non-traditional displaying applications, such as a whiteboard, desktop, or even a regular writing pad. Here we will briefly introduce our application of touch screen in the next generation Classroom Response System (CRS).
