NI Passenger Survey - survey and analysis methodology Topics: Statistics and economic research, Tourism statistics Date published: 26 May 2016 NI Passenger Survey methodology can be accessed below. Documents Northern Ireland passenger survey - survey and analysis methodologyAdobe PDF (63.14 KB)Northern Ireland passenger survey questionnaire 2015Adobe PDF (120.19 KB)Benefits and implications of the change in NI Passenger Survey methodologyAdobe PDF (52.44 KB) Help viewing documents