Web Survey Methodology: Interface Design, Sampling and Statistical Inference
In the last two decades, Web or Internet surveys have had a profound impact on the surveyworld. The change has been felt mostly strongly in the market research sector, with manycompanies switching from telephone surveys or other modes of data collection to online surveys.The academic and public policy/social attitude sectors were a little slower to adopt, being morecareful about evaluating the effect of the change on key surveys and trends, and conductingresearch on how best to design and implement Web surveys. The public sector (i.e., governmentstatistical offices) has been the slowest to embrace Web surveys, in part because the stakes aremuch higher, both in terms of the precision requirements of the estimates and in terms of thepublic scrutiny of such data. However, National Statistical Offices (NSOs) are heavily engagedin research and development with regard to Web surveys, mostly notably as part of a mixedmodedata collection strategy, or in the establishment survey world, where repeated measurementand quick turnaround are the norm. Along with the uneven progress in the adoption of Websurveys has come a number of concerns about the method, particularly with regard to therepresentational or inferential aspects of Web surveys. At the same time, a great deal of researchhas been conducted on the measurement side of Web surveys, developing ways to improve thequality of data collected using this medium.This seminar focuses on these two key elements of Web surveys — inferential issues andmeasurement issues. Each of these broad areas will be covered in turn in the following sections.The inferential section is largely concerned with methods of sampling for Web surveys, and theassociated coverage and nonresponse issues. Different ways in which samples are drawn, usingboth non-probability and probability-based approaches, are discussed. The assumptions behindthe different approaches to inference in Web surveys, the benefits and risks inherent in thedifferent approaches, and the appropriate use of particular approaches to sample selection in Websurveys, are reviewed. The following section then addresses a variety of issues related to thedesign of Web survey instruments, with a review of the empirical literature and practicalrecommendations for design to minimize measurement error.