About: http://webisa.webdatacommons.org/172174969

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	That is to say, the covariates and other data should be in the same dataframe or data matrix.
http://www.w3.org/ns/prov#wasQuotedFrom	virginia.edu