To clearly understand how interactive whiteboards could improve the teaching environment, you need to understand the sensing technologies that are used to track interaction on the screen surface. These are resistive, laser, infrared optical, camera-based optical, and ultrasonic. Among all these technologies, the most successful in commercial interactive whiteboards use electromagnetic and resistive technology.

Resistive touch screens are made up of two flexible sheets, each containing a layer of resistive material and separated by a layer of micro air gap. In operation, the two screens are pressed together, thus recording the exact location where the screen was touched. With this technology you can use a finger, a stylus or any other pointing device. Using electromagnetic technology, the board features an array of wires embedded below the surface of the board. These interact with the pen tip to give the exact location using the X and Y coordinates.

The type of stylus varies. You can use an active stylus that uses battery power or is connected to the whiteboard. There are also passive styluses that rely on electrical signals produced by the whiteboard, so they don’t require an external power source. In simple terms, the electromagnetic whiteboard can be described as having magnetic sensors that react and send messages to the computer when the whiteboard is activated by using a magnetic pen.

Apart from the two main technologies, the other technologies are also gaining momentum in the interactive whiteboard market and therefore should not be ignored. With optical infrared technology, you must press on the surface of the plate for the infrared light to be visible. This allows supporting software to triangulate the location of the stylus or marker. With this technology, the board can be made from any material.

Interactive laser whiteboard technology uses an infrared laser located in the upper corners of the whiteboard. The laser beams work by sweeping across the surface of the whiteboard using rotating mirrors. The marker or pencil used to write on the whiteboard reflects the laser beams back to the source, allowing triangulation of the X and Y coordinates. This technology works well with hard surfaces such as steel or ceramic, which also have the advantage of being easy to clean.

With ultrasonic and infrared, the stylus pen sends out ultrasonic sound and infrared light when pressed on the whiteboard surface. The board has two ultrasonic microphones that receive the sound and calculate the differences in arrival time. This helps in triangulating the X and Y coordinates. This technology also allows the board to be made of any material. However, a suitable adapted stylus or active dry erase marker is required.

In addition to these technologies, there are also other less important technologies such as frustrated internal reflection, ultrasonic only, and Wii Remote IWB. Although interactive whiteboards are technologically advanced, there are certain problems that are common with most types. For example, using permanent markers on whiteboards can cause problems. Another common problem is the risk of dents, punctures and other surface damage not experienced with normal boards.