I discovered this study online at ABC News/Washington Post. The findings were summarized and conclusions were drawn based on the questionnaire and in-person in-depth interviews. 2,086 nannies, housecleaners, and caregivers from 14 nationwide metropolitan areas responded to a standardized set of questions via landline and cell phone interviews. 190 domestic workers from 34 various scholarly organizations and worker alliances drafted and guided the research process while multiple piloted the 29 semi-structured interviews and focus groups. Translators and interpreters had to be used as nine different languages were spoken by the participants, as there were 71 different countries of origin. The study spanned from June 2011 to to February 2012 and participants were offered $20 as incentive to complete the 45-60 minute survey.
Here is a demographics chart of the domestic workers:
The study included questions about pay rates, benefits, and their impact on workers and their families; employment arrangements and employers' compliance with employment agreements; workplace conditions, on-the-job inquiries, and access to healthcare; and abuse at work and the ability to remedy substandard conditions.
Benefits and contributions to validity are as follows: the sample size was large (almost double the national acceptability rate), the drafting and revision processes and credibility of those involved, the quality and volume of questions asked, the structure and layout in which responses were formulated (i.e. focus groups), and the variety of work amongst domestic workers, leading to generalizability.