Quantifying patterns of joint attention during human-robot interactions: An application for autism spectrum disorder assessment

•We explore Joint Attention by introducing a set of behavioural metrics based on RGB-D data analysis.•We elicit Joint Attention through the use of a small humanoid robot.•We assess these metrics by comparing the behaviour of 42 ASD children with 16 TD children.•We highlight significant differences between these two groups.•We also qualitatively assess a subgroup of 14 children with ASD after 6-month of JA training.