Some of the evidence we gather may be from our systems or recorded information already collected. In many cases, however, we will have chosen indicators that can only assessed by asking people questions. Before we ponder different ways we can ask questions or gather feedback from people, we need to ensure we understand the rudimentary concepts of ethical collection. There are many online resources, dealing with these issues in more detail:

Key Resource

See for example: http://mypeer.org.au/monitoring-evaluation/ethical-considerations/.
See also: https://www.betterevaluation.org/en/rainbow_framework/manage/define_ethical_and_quality_evaluation_standards for additional discussion regarding quality and ethics in evaluation more broadly.

Nonetheless, the key issues to think about before asking people to be involved are: informed consent, voluntary participation, do no harm, confidentiality, anonymity and assessing only relevant components.