Garbage in, garbage out (GIGO) is an axiom of the
information technology industry. Organizations spend
billions of dollars per year cleansing databases of erroneous
and inconsistent information. In many cases, the
errors remain undetected until database users discover
them—usually inadvertently—or data analysis software
(called online analytical processing, or OLAP) returns
obviously unreasonable results. Most mistakes are
typographical, but many errors result from missing,
incomplete, or duplicate entries.
Validation during data entry has proven to be the best
and easiest method of minimizing data errors and
inconsistencies.