## 1 Introduction
Representative examples include projects such as AURORA ([[http://aurora.herts.ac.uk/](http://aurora.herts.ac.uk/)]([http://aurora.herts.ac.uk/](http://aurora.herts.ac.uk/)), accessed on 1 May 2022), IROMEC, DREAM ([[https://dream2020.github.io/DREAM/](https://dream2020.github.io/DREAM/)]([https://dream2020.github.io/DREAM/](https://dream2020.github.io/DREAM/)), accessed on 1 May 2022), DE-ENIGMA ([[https://de-enigma.eu/](https://de-enigma.eu/)]([https://de-enigma.eu/](https://de-enigma.eu/)), accessed on 1 May 2022) and SARACEN ([[https://twitter.com/saracenrobot](https://twitter.com/saracenrobot)]([https://twitter.com/saracenrobot](https://twitter.com/saracenrobot)), accessed on 1 May 2022), as well as other works conducted by [PERSON] and [PERSON] [22], [PERSON] et al. [23], [PERSON] et al. [16], [PERSON] et al. [24] and [PERSON] et al. [25] and commercial initiatives such as AskNAO [26]. Importantly, the main implication of these works is that autistic children have been shown to be more involved in interactions with robots than with other people [16; 22; 27]. This in turn suggests that the interaction between an autistic child and a robot can serve as a basis for the development of an observational tool for the diagnosis of ASD. It can also act as therapeutic stimulation, where it has been highlighted that children playing with robots can have a developmental impact [28; 29; 30]. Other researchers have emphasized that the robotic environment can provide predictable and reliable situations in which the complexity of interactions can be controlled and gradually increased [29]. In addition, engagement of the child playing with a robot enables more complex behavior by engaging another child or adult in a triad. In this way, autistic children can gradually practice turn-taking behaviors and tackle their social deficits [27; 31; 32]. [PERSON] et al. [16] clearly summarize how autistic children can benefit from interaction with social robots: (i) a robot can serve as a child's instructor that demonstrates proper social behavior, which is guided via interaction with the child; (ii) a robot can respond in the manner of a toy that mediates social behavior between the child and other people; and (iii) a robot can act as an agent, thus allowing him/her to express emotions and/or desires. The idea of using robots or other modern technology in the field of autism diagnosis first appeared in the literature more than a decade ago [14; 15; 16; 17; 19; 24]. [PERSON] [14]first outlined the idea of using social robots to address critical issues in autism diagnosis. This research is complemented by later work [15] on the field of social robotics, relevant technologies and the study of autism. These studies rely on passive sensing (i.e., without directly engaging in interactions, passive sensors record information on human user response such as gaze direction, focus of attention, position, vocal prosody). [PERSON] et al. [16] comprehensively outlined several important aspects of applying robotics in autism research. The main conclusion of this work is that social robots could be used to diagnose autism due to their use in a range of diagnostic settings, constant behavioral evaluations and standardized stimuli. [PERSON] [17] proposed a robot-assisted protocol based on the Autism Diagnostic Observation Schedule (ADOS) and adapted for use with the NAO robot; however, this researcher did not develop a reliable experimental environment and provided no further experimental evaluations of the proposed protocol. However, [PERSON] et al. [19] made some progress and posited that early detection of ASD symptoms through behavioral observation in the natural environment may be improved by a protocol for Child-Robot Interaction (CRI) and technology for automated assessment of behavior. The proposed CRI protocol developed by [PERSON] et al. [19] was inspired by a well-established joint attention protocol designed for computer vision, with a network of RGB-D (Red, Green, Blue, Depth) sensors for measuring children's movements.