Accuracy of travel data samples: Utilizing online vs. mail methodologies - ARCHIVED

Online data collection emerged in 1995 as an alternative approach for conducting certain types of consumer research studies and has grown in 2008. This growth has been primarily in studies where non-probability sampling methods are used. While online sampling has gained acceptance for some research applications, serious questions remain concerning online samples' suitability for research requiring precise volumetric measurement of the behavior of the U.S. population, particularly their travel behavior. This paper reviews literature and compares results from studies using probability samples and online samples to understand whether results differ from the two sampling approaches. The paper also demonstrates that online samples underestimate critical types of travel even after demographic and geographic weighting.