This paper presents a software application and the results from extensive test batteries aimed at evaluating its reliability, accuracy, and stability. The context is cognitive decline in older people and its detection, which is becoming an increasingly pressing problem in the Western world due to the aging population. The software application is the web transposition of an existing application currently available for standalone PCs. This application delivers test batteries aimed at detecting the onset of cognitive impairment. The most important advantage sought by porting the application to the web is the ability of the patients to perform the tests themselves, without medical or technical supervision.

The paper first presents the overall study design and goals, such as accuracy and response speed, and stability of results over time. Then, it describes the technical components of the application, both hardware and software, as well as the actual tests given to the patient. It goes on to explain how data are processed and normalized in order to have results that are consistent over time. The final part, the best part of the paper, is a frank discussion of the results; the authors recognize that the final results of such a study can be biased by many factors. Some of them are rather common in this kind of study, such as the loss of patients during follow up, but some are quite new, such as technical problems involved with the very use of the Internet, from network connection problems to difficulties with the use of the web interface.