Interactive whiteboards, or IWBs, are technological replacements for traditional blackboards, whiteboards and overhead projectors. An IWB consists of a large screen where images from a computer are projected. Users can interact with the computer by touching or writing on the screen with a finger, pen or stylus. Interactive whiteboards have become increasingly popular in classroom settings and corporate offices because they allow lessons and presentations to include a wider range of multimedia materials in an engaging and dynamic format. There are three main types of IWB technology available: resistive technology, electro-magnetic and laser scanners.
Resistive technology whiteboards support touch-based interaction. The whiteboard consists of a soft membrane surface that deforms when touched to make contact with a conducting plate. When contact is detected, the touch location is sent to the computer. A finger or pen can be used for interaction, which means that no special hardware is needed. Some touch-based whiteboards support the use of dry-erase markers and can replace ordinary whiteboards. In general, this is the least expensive type of interactive whiteboard. Smart Technology's line of SMART Boards are based on resistive technology.
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Electromagnetic whiteboards have an embedded wire mesh that uses electricity to create a magnetic field. When a special pen containing a coil in its tip is pressed on the surface of the whiteboard, the electrical signals produced by the mesh are altered in such a way that the pen's location can be detected. Electromagnetic whiteboards do not support touch interaction, although for some applications the precision of a pen offers a clear advantage. A company named Numonics introduced the first pen-based electromagnetic whiteboard in 1994 and continues to be a leader in the field.
The most expensive type of interactive whiteboards are based on laser scanner technology. Movement on the board is detected by infrared laser scanners mounted at each corner. Special pens with encoded reflective collars are used for interaction; the whiteboard's software can detect different colors based on the pen's collar. This type of board has a hard surface and often supports the use of dry erase markers. Qomo Hitevision is a maker of this type of interactive whiteboard.
Ultrasound / Infrared
A flexible alternative to an IWB system consists of a bar that attaches to the side of an ordinary whiteboard and connects to a computer and projector. The bar uses a stylus pen and a combination of ultrasound and infrared to detect the pen's location on the whiteboard. This type of interactive whiteboard is marketed by a company called Mimio.
Most interactive whiteboards are sold with software that provides a variety of interactive features, including handwriting and shape recognition and the ability to capture and print the contents of the board. Additional desirable features include support for multiple screens that can be flipped through like the pages of a notebook and remote-controlled videoconferencing. In response to competition in the educational market, many IWB software packages include lesson plans, tools for teaching mathematical concepts, interactive books that can be projected on the whiteboard and built-in searchable libraries of shapes, images, sounds and video.