“…When the impact on enjoyment or engagement is not assumed or implied by interpreting results from other constructs, however, games researchers have demonstrated a range of approaches to their independent measurement (E. P. Downs & Oliver, 2016;Isbister, Rao, Schwekendiek, Hayward, & Lidasan, 2011;Limperos et al, 2011;Sah, Ahn, & Sundar, 2010;Shafer et al, 2011). These vary from tracking body movement (Bianchi-Berthouze, 2013), as discussed in section 2.1.2, to using a range of existing validated instruments (Bianchi-Berthouze, 2013;Limperos et al, 2011;Shafer et al, 2014) or custom-designing scales to operationalise these constructs within the context of study (J.…”