This piece by Dave Beech from 2008 has been very helpful to think through the ethics of the invitation to participate.
Include Me Out, Dave Beech
"...... participation always involves a specific invitation and a
specific formation of the participant’s subjectivity, even when the
artist asks them simply to be themselves. The critique of participation
must release us from the grip of the simple binary logic which opposes
participation to exclusion and passivity. If participation entails its
own forms of limitations on the participant, then the simple binary
needs to be replaced with a constellation of overlapping economies of
agency, control, self-determination and power..."
"One way of getting a handle on the limitations and constraints imposed
on the participant is to contrast participation with collaboration. It
is the shortfall between participation and collaboration that leads to
perennial questions about the degree of choice, control and agency of
the participant. Is participation always voluntary? Are all participants
equal and are they equal with the artist? How can participation involve
co-authorship rather than some attenuated and localised content? The
rhetoric of participation often conflates participation with
collaboration to head off such questions. Collaborators, however, are
distinct from participants insofar as they share authorial rights over
the artwork that permit them, among other things, to make fundamental
decisions about the key structural features of the work. That is,
collaborators have rights that are withheld from participants.
Participants relate to artists in many ways, including the
anthropological, managerial, philanthropic, journalistic, convivial and
other modes. The distinction between them remains."
Dave Beech
http://www.artmonthly.co.uk/magazine/site/article/include-me-out-by-dave-beech-april-2008