Telephone surveys are very useful research tools when designed to control for demographic data and when performed by skilled interviewers. They allow for the collection of a large body of data for a relatively low cost, and maintain a fairly high level of reliability. In addition, the use of bilingual interviewers, particularly Spanish language interviewers, allows more residents the option of participating in surveys.

DHM Research incorporates a mixed sample design in our telephone surveys that includes random digit dialing (RDD) and cell phone sample. Over the years, securing respondent cooperation for telephone surveys has become more difficult with the increased use of cell phones. While DHM Research sets quotas to ensure a representative sample, especially for 18-34 year olds, there is also concern that there are attitudinal differences between cell phone only residents and their counterparts. While research has shown that the difference between cell phone only and LAN line respondents is nominal (2-3 percentage points, if at all), we believe incorporating cell phone sample is important to secure the participation of younger and more mobile residents.