  Novel end-user programming (EUP) tools enable on-the-fly (i.e., spontaneous,
easy, and rapid) creation of interactions with robotic systems. These tools are
expected to empower users in determining system behavior, although very little
is understood about how end users perceive, experience, and use these systems.
In this paper, we seek to address this gap by investigating end-user experience
with on-the-fly robot EUP. We trained 21 end users to use an existing
on-the-fly EUP tool, asked them to create robot interactions for four
scenarios, and assessed their overall experience. Our findings provide insight
into how these systems should be designed to better support end-user experience
with on-the-fly EUP, focusing on user interaction with an automatic program
synthesizer that resolves imprecise user input, the use of multimodal inputs to
express user intent, and the general process of programming a robot.
