  Robots in urban environments will inevitably encounter situations beyond
their capabilities (e.g., delivery robots unable to press traffic light
buttons), necessitating bystander assistance. These spontaneous collaborations
possess challenges distinct from traditional human-robot collaboration,
requiring design investigation and tailored interaction strategies. This study
investigates playful help-seeking as a strategy to encourage such bystander
assistance. We compared our designed playful help-seeking concepts against two
existing robot help-seeking strategies: verbal speech and emotional expression.
To assess these strategies and their impact on bystanders' experience and
attitudes towards urban robots, we conducted a virtual reality evaluation study
with 24 participants. Playful help-seeking enhanced people's willingness to
help robots, a tendency more pronounced in scenarios requiring greater physical
effort. Verbal help-seeking was perceived less polite, raising stronger
discomfort assessments. Emotional expression help-seeking elicited empathy
while leading to lower cognitive trust. The triangulation of quantitative and
qualitative results highlights considerations for robot help-seeking from
bystanders.
