Dynamic difficulty adjustment (DDA) in exergames uses player data to modify game challenges, balancing difficulty with player ability or fitness. DDA in exergames can be categorised into two types: exercise intensity (EI)-based and performance (P)-based. However, insight into how they impact players is limited.
This thesis investigates how different DDA functions influence player experience (PX) and physical effort using a bespoke running exergame as the case study. This was done using within-subject quantitative design with counterbalancing. The impact on PX was assessed using established questionnaires and physical effort was measured through average heart rate (AHR).
Experiment 1 (N = 26) explored two EI-based DDA types: continuous EI-based DDA
(DDA1), aiming to maintain AHR in the aerobic zone, and interval EI-based DDA (DDA2),
alternating between low and high intensity, compared to a no-DDA condition (nDDA). Both DDA1 (p < .001, d = 1.00) and DDA2 (p = .011, d = .64) significantly increased AHR
compared to nDDA, with no difference between DDA1 and DDA2 (p = 1.000, d = .18).
Perceived exertion was higher in DDA1 than in both nDDA (p = .006, r = .54) and DDA2
(p = .015, r = .48), while no significant difference was found between DDA2 and nDDA
(p = .323, r = .19). However, EI-based DDA did not influence other PX.
Experiment 2 (N = 43) examined P-based DDA (DDA3), adjusting difficulty based on setback counts. DDA3 significantly improved challenge-skill balance (p = .026, r = .34), perceived competence (p = .018, r = .36), and AHR (p = .036, d = .33) compared to nDDA.
Experiment 3 (N = 36) compared DDA3 to a novel P-based DDA (DDA4), adjusting difficulty before setbacks occurred. DDA4 significantly enhanced challenge-skill balance (p = .017, r = .40), increased competence satisfaction (p = .002, r = .51), and reduced competence frustration (p = .040, r = .34) compared to DDA3.
This research provides insights into how DDA functions impact players, suggesting that different DDA functions influence players in distinct ways, opening opportunities for using this knowledge in designing exergames and DDA.
