“…The main aspects of interviewing include the selection of informants, the sample size, the format of interview or questionnaire employed (Davis and Wagner, 2003), and the use of other sources to corroborate the informants' reports (Robertson and Mc Gee, 2003). As regards to the format of the interview, most of the studies reviewed appear to have used semi-structured interviews (Lykke, 2000;Zurayk et al, 2001;Nyeko et al, 2002;Peroni and Hanazaki, 2002;Di Mauro, 2003;Grossman, 2003;Mc Donnald et al, 2003;Desbiez et al, 2004;O'Rourke, 2005), because the results are easier to process than those from unstructured interviews, employed in other studies (Cudlínová et al, 1999;Mendez et al, 2001;Robertson and Mc Gee, 2003). This is particularly important when informants' reports are compared to information from other sources (historic archives, aerial photographs, inventories, etc.)…”