With the advent of affordable large display screens and with the emergence of more sophisticated sensing technologies, Mid-air Interactive Information Display is becoming more common in physical public spaces. In the field of human computer interaction, Mid-air interaction has received great attention around the world and even is considered as the trend of future. The recognition of Mid-air gestures enables designers to create interfaces that enable explicit control of such systems. This Mid-air gestures undoubtedly makes public displays more attractive to passersby and easily make them to get involved with it, but still does not exploit the full capabilities of interactive displays that actively engage the user in public setting. One of the biggest challenges is interaction blindness. Despite holding important information or fun interaction, people fail to interact with a display because they can’t discover that the system is interactive. I believe research is needed to design a discoverable interaction system, engaging enjoyable experience, learnable context to engage users, provoke their curiosity, and hold their attention longer for mid-air gestures in public space. In this thesis, I explore to identify characteristics of engaging visual feedback on public displays, identify design heuristics for discoverable mid-air gestures and develop a methodology for evaluation engagement in interactive systems.