Whereas traditional Stated Preference experiments typically have a small number of alternatives, online travel agents (OTA) usually present a large number of ticket options for any given day. To help the customers deal with the large amount of information, most OTA sites allow the flights to be sorted on at least some of the attributes. Furthermore, after an initial search for specific dates, the search can be refined in various ways, so that flights that do not meet a specified criteria are not shown. In a departure from traditional SP methodology, we have tried to mimic the decision making process of a visitor to an OTA site. This approach includes a large number of alternatives that are based largely on real flight information, and the provision of extensive search and sort tools.