Il disegno campionario e il piano di rilevazione nell'indagine sui turisti incoming in partenza dalla Sicilia e dalla Sardegna: il campionamento spazio-temporale per popolazioni hard to reach

This paper aims to describe the sample design and the survey plan used in the survey on incoming tourism in Sicily and Sardinia. The specific goals of the survey are related: a) to the measurement and the analysis of un-observed tourism; b) to the evaluation of tourist mobility within the two Islands; c) to the analysis of some key-factors related to the holyday experience of tourists. It is well known that regional tourists are very difficult-to-reach populations and the problems in sampling human mobile populations derive from the absence of a list of units component units (frame). Despite these issues are well-known in literature under the broader categories of hard to reach, or hidden, or mobile populations, etc., the methodological solutions and most of all the empirical applications in tourism studies are almost poor. The sampling strategy undertaken to analyze non resident tourists leaving Sicily and Sardinia at the end of their vacation is a complex, multi-stage, stratified Time-Location Sampling (TLS). Under this perspective, the availability of information on the distribution of tourism flows by time (months) and space (departure places) for the two Islands was a fundamental prerequisite for the implementation of the sample design. Key words: Hard-to-reach populations; mobile populations; time-location sampling; time-space sampling; frontier surveys, border surveys. Parole chiave: Popolazioni mobili; campionamento spazio-temporale; indagini campionarie alle frontiere.