Environmental Engineering Reference
In-Depth Information
Comparing with the force sensing of traditional touch screens, the virtual force can give a
much greater force range. The depth of the action space can be easily adjusted by the virtual
boundary. By using cameras with wide viewing angles, the action space can be large enough
to yield many interesting 3D motions, which can be important for active computer games or
on screen calligraphy or painting. Currently, the pull, push, or similar motions are absent in
many applications. If used, they can greatly improve the user experiences.
Further, the users do not even need to physically touch the screen. As long as the pointer or
finger is in the action space, its movement will be monitored and reflected on the movement
of the corresponding cursor or object in the program.
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).
5.1 Need of the next generation CRS
Actively engaging students in classrooms is always a challenge to the teachers (Smith, 1996;
Zhang, 1993). People have tried various ways to improve the interactions even from the
early days of chalk and board (Bransford et al, 2000). Choosing a volunteer from raised
hands and picking a name from the roll topic of the class are two most common traditional
methods. However, these methods only give teachers feedback from a small fraction of the
class. The sample is often not typical or representative. Many students will not volunteer for
fear of public mistake and embarassment. As the result, a small vocal minority will skew the
view of the teacher of how the entire class understand the topic (Caldwell, 2007). To increase
the sample size, people also tried methods such as shouting the answers, applause, or
response cards (Karen et al, 2001), all with their pros and cons. More recently, computer
based technologies are introduced to classrooms. They enabled teachers to explore more
options (Patten, 2006; Richard et al, 2007; Roschelle, 2003).
The first technology used is computer-based visuals such as Powerpoint (Anderson, 2004;
Bannan-Ritland, 2002; Liang et al, 2005). It has become ubiquitous today, but with mixed
results. The slide shows help to provide strong graphical impact as “one picture worth a
thousand words”. However, the interactions and feedbacks from the students are still
greatly limited. Sometime, the situation is even worse when the light is dimmed to improve
the visual contrast.
Recently, a small gadget called Clicker, or the first generation CRS, is gaining momentum
among teachers throughout the K-12 and higher education, and to anywhere with a group
of audience (Nicol et al, 2003; Siau et al, 2006). A clicker is a remote-like device that comes
with a number of buttons and a wireless transmitter. After the instructor giving out a multi-
choice or true/false question, the students punch the buttons on their Clickers to select their
