Measuring task engagement as an input to physiological computing. - Stephen H. Fairclough; Katie C. Ewing; Jenna Roberts (ACII, 2009)

Capturing user engagement via psychophysiology: measures and mechanisms for biocybernetic adaptation. - Stephen H. Fairclough; Kiel Mark Gilleade; Katie C. Ewing; Jenna Roberts (Int. J. Auton. Adapt. Commun. Syst., 2013)