Evaluating the Cluster Scanning System

Many physically challenged users cannot interact with a computer through a conventional keyboard and mouse. For example, spasticity, amyotrophic lateral sclerosis and cerebral palsy confine movement to a very small part of the body. People with these disorders may interact with a computer through one or two switches with the help of a scanning mechanism. Scanning is the technique of successively highlighting items on a computer screen and pressing a switch when the desired item is highlighted. We have developed a new scanning system that works by clustering screen objects in a graphical user interface (GUI). Currently we have implemented it for Microsoft Windows operating system, however it can be extended to any other GUI based operating systems. In a previous paper we compared the cluster scanning system with other scanning systems using simulation (Biswas and Robinson, 2008a). In this paper we validate the results obtained in simulation by evaluating the cluster scanning system through a controlled experiment with motor impaired users. We describe the scanning systems and results obtained using simulation in the following two sections. In Section 11.4, we present our study followed by concluding remarks.