Getting the right participants is key to obtaining relevant results. The following profile requirements should be covered during the kick-off session too.
The participants
Demographic requirements
Frequently, the study sponsor can provide the demographics of the participants to be recruited, based on who their typical users are. Having no hard requirements is an acceptable response, because while an educative app for toddlers will only be relevant to parents of young children (and their children, of course), an email application, for example, is very broadly used, and it would probably be difficult to narrow it down to specific demographics.
Some common demographic characteristics that might be relevant include the following...