For most data quality assessments, we wish to determine the suitability of the data for a particular substantive analysis. In this study, we had three objectives for data quality assessment: 1) What can we learn about bias or other error in the survey process for gathering NSECE data? This information is relevant for any analyses using the NSECE household survey data, and perhaps for other studies using similar data collection methodologies. 2) What can we learn about the data quality properties of newly available research datafiles from Zillow.com? This information helps inform a variety of potential research efforts that seek to exploit administrative and commercial data to enhance survey data sources. 3) What are the properties of a linked NSECE-Zillow datafile, and what do those properties indicate about potential uses of the linked data to answer substantive questions about ECE usage by different types of families in different types of communities? (author abstract)