About: http://webisa.webdatacommons.org/18936090

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	5Age, educational attainment, and other variables are measured at the time the spells begin, except that, for those who are already on programs at the start of the survey, these characteristics are measured at the first interview.
http://www.w3.org/ns/prov#wasQuotedFrom	libraryindex.com