Consumer eHealth products are often used by people in their own homes or other settings without dedicated clinical supervision, and often with minimal training and limited support--much as eCommerce and eGovernment applications are currently deployed. Internet based self-care systems have been advocated for over a decade as a way to reduce costs and allow more convenient care, and--because of the expectation that they will be used to reduced health cost--, by increasing self-care and avoiding hospitalization. However, the history of consumer eHealth interventions is mixed, with many unsuccessful implementations. Many consumer eHealth products will form part of a broader complex intervention, with many possible benefits and effects on both individuals and society. This poster describes a model of consumer eHealth assessment based on multiple methods of usability evaluation at different stages in the design and fielding of eHealth systems. We argue that different methods of usability evaluation are able to give valuable insights into the likely effects of an intervention in a way that is congruent with software development processes.