Introduction to Sketch Recognition

Summary
Tracy Hammond and Kenneth Mock

The paper starts with a description of the Sutherland technology called Sketchpad (reviewed here).
A discussion about passive vs active digitizers follows. A Digitizer is the technology that allows Tablet PCs to recognize where the writing instrument is. Passive digitizers allow the use of finger based input, but had the drawback that if one's palm touches the screen an unintended click will be recorded. This phenominon is called vectoring. Active Disgitizers emit electromagnetic signals that are reflected by a pen or stylus and can be interpreted by the system to be in either hover mode or tapping mode.
Tablet PCs come in two types: convertible and slate. Convertable tablet PCs allow the screen to be rotated and closed with the screen accessible for writing on. In this scenario the screen covers the keyboard. In the slate style the keyboard is removed.
There are also USB connected Pen interfaces. Intuous and Graphire capture both pen data and pressure data. Airliner is a wireless slate in which multiple units can be used to edit the same Smart Board. Another type of input device is the Cintiq 21ux display which is high resolution and can be used as a second monitor.
Software that can be used is Camtasia which can record srceen interaction and audio--making for robust presentations to be watched at later times. Microsoft XP and Vista have handwriting recognition built in, and some versions of Linux can be loaded onto a Tablet PC. Apple offers some hand writing recognition software but no devices as they were burned early in their careers by immature technologies. Hammond has created a software suite called LADDER which can recognize mechanical systems and simulate the systems drawn. Other areas where this type of recognition has taken place is in Chemistry, FSM, and Music.
The FLUID framework allows anyone to design a graphical diagram, create a LADDER doamin, integrate with GUILD (automatically creates sketch recognition and editing specified by the LADDER domain) and load onto a tablet PC for interaction.
Some case studies were discussed: 11th and 12th grade pre-calculus, calculus and trigonometry and 8th grade pre-algebra and algebra. Both examples show how a teacher could benefit from the use of Tablet PCs by describing how they could use them in their classes.


Discussion
This paper was a good overview of the physical devices and software availbale for sketch based capture and processing. The most interesting parts of the paper came from the way the technology can be used to enhance the learning experience and role of the teacher. While I would ike to have seen some more analysis on the success rates of using the technology in classrooms I believe that this is a great avenue for class interaction and facilitated learning not normally seen. It is engaging and active rather than passively listening to a lecture.