Individuals who experience temporary, intermittent, or gradual changes in pointing ability may encounter frustrating experiences when using computer input devices. Personalized pointing systems that automatically assess changes in performance and provide individualized information and assistance may benefit these users. However, there has been little inquiry into this populations' expectations for interacting with these types of systems. We describe a participatory design process in which we used a technology probe to assess the information needs and expectations of 27 individuals who experience occasional changes in pointing ability, through interactions with and discussion regarding a high-fidelity personalized pointing prototype. Participants preferred notification and adaptation interactions that provided them with control and explanation of system actions, instead of abstract notifications and automatic adaptations. We describe how we applied these finding in the design of the PINATA system.