Such endeavors require computers with great computational speed and systems with large amounts of disk storage. Such high-end applications may require systems that run continuously for days or weeks, surpassing the reliability requirements of administrative systems. Massive data may require very high-speed networks for transmission. Document preparation in the sciences involves heavy use of formulae, mathematical and other symbols, graphics and tables. Specialized software such as TeX for the production of these documents is common.
Social scientists collect primary data that is often analyzed using statistical software.
Existing demographic data from the Census Bureau and other federal agencies is often needed for research. Geographers make use of satellite images, GPS systems, GIS software and produce graphics that must be displayed on special devices. Programs written in audiology and psychology perform basic and applied human subject research. Resulting experiments can involve interfacing laboratory equipment to computers. General purpose computers are often used in combination with discipline-specific software purchased or written for particular applications.