autonomy [49], forming the basis for AI interface design. However, there’s a gap in understanding
expectations of human-AI interaction outcomes, such as task performance with AI support [40].
The placebo effect [5, 20, 33, 41, 53, 58] is not confined to medical contexts but also penetrates
performance contexts like sports [7]. Here, an inert substance given to athletes can improve but also
deteriorate performance [35]. While placebo effects of AI in HCI and their effect on performance
have recently been studied [18, 40, 74, 78], there is very little knowledge on nocebo effects. In HCI,
AI enhance sour performance