Design of Effective Robotic Gaze-Based Social Cueing for Users in Task-Oriented Situations: How to Overcome In-Attentional Blindness?  
[PERSON]  
1 School of Computer Science and Electrical Engineering, Handong Global University, Pohang 37554, Korea; [EMAIL_ADDRESS]  
2 Department of Biomedical Engineering, School of Engineering and Applied Science, George Washington University, Washington, DC 20052, USA; [EMAIL_ADDRESS]  
3 Robots in Education & Entertainment Lab., Hansung University, Seoul 02876, Korea; [EMAIL_ADDRESS]  
4 Division of IT Convergence Engineering, Hansung University, Seoul 02876, Korea  
5 Correspondence: [EMAIL_ADDRESS]; Tel.: +82-2-760-4345  
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information; and typically the gazing activities are fused into multi-modal communication with speech, facial expressions, or bodily gestures [1, 2].  
This complex nature of human gaze has fascinated the minds of roboticists in developing more advanced robotic systems with naturalistic and effective human-robot interaction modalities [1, 3, 4, 5, 6]. It has been widely studied that gaze functions in human-robot interaction can play a similar role in human-human interaction [7]. Previous research efforts on robotic gaze, to list a few, have studied the role of gaze as a strategy in social human-robot interaction [8], applied in robotic gaze control of a humanoid system and evaluated the performance [9], implemented more natural human-like gaze behavior and evaluated its impact in storytelling scenarios [10], and applied to industrial assembly tasks in human-robot collaboration [11]. Robot's gaze can also affect robot's interpersonal relationship, life-likeness, cognitive competence, social attentiveness, and information disambiguation [11]. However, did we fully achieve the full bandwidth of gaze-based social cueing with robotic systems?  
The limitations of robotic gaze have reported that the effectiveness of the robotic gaze is not as effective as human gaze [12, 13]. The robotic gaze is also known to be not capable enough to achieve social communications (e.g., joint visual attention measured through reflexive attention) when tested with simplistic robotic platforms such as Zeno or Keepon [12]. While more recent studies are presenting positive results by adopting advanced human-like eye gaze controllers [14, 15], and utilizing eye-tracker technology to provide more adaptive and responsive joint attention [16, 17, 18], there still lies in real human interaction scenarios in which the robotic gaze control is not capturing the full aspects of human-human interaction.  
One of the most frequent cases in human-robot interaction where the robotic gaze is not performing at full capacity is the in-attentional blindness (IB) case, arising in many task-oriented social communications. The IB in human-robot communication arises when the human's attention is not aligned with robotic gaze due to its focus on other objects or tasks [19, 20], thus causing blindness toward the robotic gaze. Thus, in this work, we present a method for a social robot to adequately deliver gaze-based social signals competing for the participant's attention with varied visual stimuli. This is particularly crucial in educational environments, where multimedia contents are utilized frequently alongside the tutor (robot) for enhanced learning.  
With this objective in mind, Section 2 discusses the prior work in robotic gaze control as well as the definitions of IB, and Section 3 presents the hypotheses of this study in robotic gaze for social cueing in an IB scenario. Section 4 discusses our experimental design and the methodologies we created to implement an effective gaze-based social cueing framework. Section 5 presents the results of our experiments conducted with 93 participants, and Section 6 discusses our findings and outlines future steps.