The ultimate goal of this research is to understand how current visualisation practices may affect an interpretation; and ultimately to design and implement more effective visualisation and interpretation methods. As a first step toward these goals, this study aims to understand how interpreters interact with the data when conducting specific tasks and to analyse variability in interpretation process between and within individuals. To achieve this we monitor the neurological and physiological responses of interpreters as they work using an eye tracker system (ETS) that tracks their vision during data observation and an electroencephalography (EEG) that captures brain responses as the interpretation proceeds. This is a Ph.D study by Yathnanthan Sivarajah.