The Astrophysics Data System (ADS), developed by the National Aeronautics and Space Administration (NASA), is an online database of over eight million astronomy and physics papers from both peer reviewed and non-peer reviewed sources. Abstracts are available free online for almost all articles, and full scanned articles are available in Graphics Interchange Format (GIF) and Portable Document Format (PDF) for older articles. New articles have links to electronic versions hosted at the journal's webpage, but these are typically available only by subscription (which most astronomy research facilities have). It is managed by the Harvard–Smithsonian Center for Astrophysics.
ADS is a powerful research tool and has had a significant impact on the efficiency of astronomical research since it was launched in 1992. Literature searches that previously would have taken days or weeks can now be carried out in seconds via the ADS search engine, custom-built for astronomical needs. Studies have found that the benefit to astronomy of the ADS is equivalent to several hundred million US dollars annually, and the system is estimated to have tripled the readership of astronomical journals.
Data system is a term used to refer to an organized collection of symbols and processes that may be used to operate on such symbols. Any organised collection of symbols and symbol-manipulating operations can be considered a data system. Hence, human-speech analysed at the level of phonemes can be considered a data system as can the Incan artefact of the khipu and an image stored as pixels. A data system is defined in terms of some data model and bears a resemblance to the idea of a physical symbol system.
Symbols within some data systems may be persistent or not. Hence, the sounds of human speech are non-persistent symbols because they decay rapidly in air. In contrast, pixels stored on some peripheral storage device are persistent symbols.
In education, a data system is a computer system that aims to provide educators with student data to help solve educational problems. Examples of data systems include Student Information Systems (SISs), assessment systems, Instructional Management Systems (IMSs), and data-warehousing systems, but distinctions between different types of data systems are blurring as these separate systems begin to serve more of the same functions. Data systems that present data to educators in an over-the-counter data format embed labels, supplemental documentation, and help system and make key package/display and content decisions to improve the accuracy of data system users’ data analyses.