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)