What's the issue?
It is essential to show respect for those who participate in research projects. This applies not only to interviewees but also to people who participate indirectly like parents and teachers. In all cases it is important to show all individuals who participate in a research project that their contribution is valued. Feedback on the findings is one part of this.
When a study has been conducted and the results are ready it is good practice to let those who contributed in some way know that the results are out and where they can be found. For example if a school has provided access to its students the headmaster would receive a letter of gratitude and a copy of the research report.
As a general rule, the more you ask of the participant the more you have to show him or her that you value the contribution. In line with that it is more common to see researchers seek feedback or approval from interviewees in qualitative research but relatively uncommon in quantitative research.
In qualitative studies it is good practice to ask for feedback from individuals that are quoted directly in a research report and individuals should not be quoted by name unless they have given their permission.
Pitfalls to avoid
When asking for feedback from interviewees it is important to think that process through so that it is done within a clear frame.
What kind of feedback is wanted?
What is to be done with the feedback?
Will the research results be changed if interviewees think the interpretation is misleading or incorrect?
If an interviewee is unhappy with an anonymous quote from him and her and wants it to be dropped even if it is exactly what he or she said?
Questions to consider
A special issue when conducting research on children is that research findings inevitably are adult interpretations of the reality of children. In that respect it can be very relevant to seek feedback from children on the research findings but then again scientific work often uses language and concepts which might be difficult for children to understand.
If it is decided to seek feedback from interviewees it is worth to think carefully about the process as it would sometimes be difficult to get feedback without letting others (parents or teachers) see their answers. A letter addressed to a teenager might for example be opened by a parent.
See: http://www.hbsc.org/ as an example of a website which gives access to survey findings. Also http://www.hbsc.is/ as an example on the national level where schools could get access to reports tailored to the interests of teachers and headmasters.
In Iceland schools have in recent years become increasingly resistant to surveys. The reason is that due to the relatively small population it has become customary to survey whole cohorts as there are only about 3.500 children in each cohort. But it requires a lot of work on behalf of the schools to administer the questionnaires and therefore it is important that the teachers and headmasters can see that their efforts lead to meaningful results. This has encouraged some researchers to send the schools summary reports of findings.
Another example of this kind is the TIRO research project in Belgium where the same reluctance of schools (in particular in the bigger cities) to participate in surveys has been encountered. The schools that agreed to cooperate were invited to the Safer Internet Day Happenings and received an executive summary of the findings.