Objectives: To investigate the relative effectiveness of different prompts for people with dementia during multistep tasks in the home, to inform prompting technology design. Methods: Nine pairs of participants (one with dementia and a partner or relative) participated at home. The participants with mild to moderate dementia (5M/4F, aged 73-86 years) functioned at the Planned or Exploratory levels of the Pool Activity Level instrument. A touchscreen computer displayed different prompts during two set tasks: "card-and-envelope" and "CD player." The trials were scored to establish the relative effectiveness of the prompts. Individual tasks were also explored. Results: Text and audio prompts were each more effective than video or picture prompts for a card-and-envelope task, but this was not seen in a CD player task. The differences may be related to the type of actions within the tasks; the card-and-envelope actions were easier to convey verbally; the CD player actions lent themselves to visual prompts. Conclusions: Designers of technology-based prompts for people with dementia should consider that the effectiveness of different prompts is likely to be task dependent. Familiar, unambiguous language can increase the success of tailored prompts. There are significant practical challenges associated with choosing and deconstructing everyday tasks at home.