I don't think that is the full explanation, given that the system scores pretty well (84%) even from one swipe. it measures size of impact area, pressure, speed etc.
Yes, what I meant. The awkwardness vs unawkwardness of the swipe. Does the finger alight and glide, or bash down and judder across the screen? Does it land just in the exit zone of the first hotspot and depart immediately it is drawn over the final spot, or resolutely brought to the exact centres/is over-dragged beyond? In a complex (single) gesture, are the angles sharp stops and redirections or do they swoop in a perceptible curve?
All possible diferentiations that could be amplified by age (or lack of), but then in which direction does
experience now go? Does learning to be more flamboyant and 'easy' send
either age-group towards looking like the other?
(Was it all a function of the test they set up? Same tablet set flat upon the same table with the same chair, meaning littler bodies operated the device more obliquely
1 compared to the more top-down stabbings of the adult digits. Loads of speculation to be had, no doubt addressed in a more comprehensive review of the research results, but drifting around conspicuously unanswered in that initial report.)
1 Smaller fingers, also, don't forget! Surely they accounted for that? Did a side-experiment with a stylus (pressure, positioning and tracking effects, losing the size aspect) reveal detectible differences?