SRO hotels may be literally invisible to higher-income passers-by when they are discreetly located on the upper floors of a restaurant or retail store. There is a debate as to whether SRO hotel residents are "homeless." Paul Groth states that SRO residents are "not homeless. They are living in admittedly minimal and unusual dwelling units, often in hideous repair and under woefully inadequate management but dwelling units nonetheless." SROs were considered socially acceptable even as late as the late 1950s: the Alfred Hitchcock movie "Vertigo" depicted young administrative staff living in downtown SRO hotels. An equivalent term to SRO is "residential hotel".