Data organized into data files and data banks was primarily numerical and was used for analysis and decision making. With the advance of information technology computers can store and process increasing amounts of all types of data. With the advent of multimedia computers and massive storage, data files can be any combination of numbers, text, symbols, sound, both still and dynamic images. Indeed, any computer data file constitutes data under our definition. Our primary concern will be data for analysis and decision making.
Many computer files are likely to be used only very occasionally for analysis or decision making.
For example, a music professor making a study of the evolution of rock music could analyze a data file of rock music sound. Likewise a data file of digitized movies could be used to study the evolution of cinematography. Nevertheless, in most cases such files will be used for recreational purposes. Information will be defined as useful data for a particular analysis or decision task. For many tasks useful data is observations of behavior recorded as numerical measurements, text, symbols, voice messages, or images.