Chapter 8: The Challenges of Surveying ‘Hard to Reach’ Groups: Synthesis of a Workshop

The basic premise of a probability sample is that the sample will represent the universe or target population. To achieve that goal, pertinent information about each sample unit should be obtained. When some groups are not included, representation of the universe within the sample is brought into question. So, one goal of survey research is to maximise the probability of obtaining information about each sample unit.

In every survey, there are groups that may be underrepresented because they are difficult to include. This chapter discusses challenges facing the inclusion of so-called ‘hard to reach’ groups in travel surveys, and explores methods that might be applied by travel survey practitioners to ensure representation of these groups. The content of the chapter is based upon deliberations within a workshop session on this topic, at the 8th International Conference on Transport Survey Methods.