is about
data item
directive information entity
statistical variable
Yongqun He
WEB: http://www.abs.gov.au/websitedbs/a3121120.nsf/home/statistical+language+-+what+are+variables
WEB: http://en.wikipedia.org/wiki/Variable_%28mathematics%29
A directive information entity that specifies a data item that can be measured or counted and is used in a statistical analysis.
variable