I encountered the following situation in a 1930 census of a
household of a family I am researching: In addition to mother
(head) and daughter, there is a roomer, and three girls with the
same last name (ages 15, 13, and 11) shown as boarders. What are
the definitions of the two terms? (My guess is that this was a
foster household for the three girls.) What is the definition of
the term "lodger" relative to the preceding? Would these terms
be used consistently across all censuses?