For the past twenty years, DDG has been collecting data for a massive, multi-utility customer satisfaction study. Because many of these utilities service residential customers in geographies that are heavily rural, where Internet access is not a guarantee, this study has heretofore been conducted using a telephone data collection methodology. However, as TCPA restrictions on the use of predictive dialers, decreasing penetration of land lines, and flagging telephone response rates have made meeting monthly targets more and more challenging, DDG undertook a significant redesign of the study to allow for multimode data collection. For the first time, online interviews would supplant some of the telephone interviews.
The surveys were reprogrammed into a single multimode instrument, enabling the efficient sharing of complex, nested quotas irrespective of mode. This meant that no complicated management of monthly targets was required. Beta testing was conducted in Q4 of 2017 before full rollout in January of 2018.
A critical aspect of the sample plan for this research is the EPSEM (Equal Probability Selection Method) sampling requirement, whereby each member of the population has an equal and known probability of being chosen to participate in the study. Simply put, the sample selection for each month of fieldwork was designed to ensure that no customer had a higher chance of being selected for the study than any other, regardless of whether an email address was available for them. If sampled consumers don’t respond to the utility-branded email invitation, the data collection system automatically moves them over to get a phone call once we reach a certain point in fieldwork.
So far, we have conducted eight months of multimode fieldwork. To maximize the number of online completes we acquire (thus minimizing costs for the utilities), telephone and web data collection must be carefully timed and managed. Generally, these utilities have email addresses for about half of their customers, so we aim to deliver about half of the completed interviews on the web. In early months, the proportion of online interviews was lower, yielding between 25-35% of all interviews. Each month different combinations of phone sample release and web communications were tested until we found the optimal mix that yielded the 50% web completes we were aiming for. Currently we are working with the utilities on ways they can eventually boost this percentage, and even possibly transition to doing the entire study on the web.