There are many ways you could approach this. It is not clear why, if there is victimization taking place you would want this to be anonymous as such data might allow you to determine the scale of the problem but is likely to leave the organization without a method to address such issues.

Approaches may depend on the stage of career (undergraduate vs postgraduate) and the number of students. For example - in some institutions postgraduate research students may have a yearly independent review (by someone other than their mentor / supervisor) - this provides a forum for this. For undergraduate students, the use of student support teams and fostering a reporting mechanism through that could be helpful.

It may be worth looking at other areas of supervision / mentor practice for ideas. For example, in clinical supervision provided to mental health staff, standard approaches to audit can be used to monitor for such activity (see chapter 9 in Davies, J (2015) Supervision for Forensic Practitioners. Routledge. Such simple audit methods can provide clear information about the nature and type of activity including difficulties.

There is a possible second question underpinning your idea above - why is this happening. Has something changed which has led to this being more evident?

Not sure why we are so surprised by the amount of tension and friction that is experienced within supervisory relationships. That friction, tension and those power dynamics exist in all classrooms, and will of course be equally prominent in one on one relationships in Graduate Education within Higher Ed. The lens of ecological theory is really useful here: in enabling us to see both instructor and learner as involved in multiple systems, it leads us to examine one-on-one relationships between the two in terms of 'fit' or 'lack of fit'. Lots of work done around this in schools, particularly in the field of challenging behaviour where it has helped institutions realize that tension in the classroom is not a one sided phenomenon but that both parties need to look at the subjective emotions they bring to the table. We need to extend that lens to our examination of the higher classroom and more importantly Graduate Education.

I agree with Davies

This is an interesting project. The causes of such bias in student supervision may be largely based on students' performance, dedication to their projects and cooperation to their thesis supervision. Naturally, we afford more supervisory roles with diligent students who take advice and work arduously. On the other hand, we then not to give quality time to those who are lazy and act like 'tortoises' in their projects due to lack of dedication to their thesis and diligence to their projects.

Is there a power struggle going on, like in any relationship, as the relationship is between a supervisor and a 'supervisee', therefore it needs to be developed, nurtured, and consolidated, yes?

Are gender, experience, age, and time other factors to consider?

Is implicit knowledge (e.g., values, beliefs, perceptions, etc.) a factor?

What can a victimised student do to seek justice if the institution support the abuser?

This is a very interesting question but I would like to post back for clarity. How do you envision victimization? Are we discussing H student faculty relationship in which sexual improprieties have occurred, academic improprieties, a hostile environment within the work/academic setting or all of the above? I have seen situations in which students became the pond between rival faculty members and were often caught in the middle before they realized the difficulty of the situation. We stayed in place. I've also seen students and exploited by faculty members for the purpose of, on the part of the faculty member, gaining additional publications primarily off the back of students. We've all seen the unfortunate results of inappropriate faculty student relationships. For some of the students they will take steps to get issues resolved within the University setting. For others, they have often the part of the institution before the real situations of their departure is understood. When I served as chair of academic departments. I tried to maintain an open door policy to assist students and faculty, where appropriate. In some cases, I would prefer them to other resources within the University setting, but I always documented the encounter and maintained it in a confidential file. Where appropriate follow-up attempt to ensure the issues or concerns would be addressed.

Findings on the study of the influence of celebrities on behaviour of adolescents revealed that student imitated homosexuality and lesbianism from celebrities as they felt it was fashionable to do so.The supervisor does not want to be associated with such findings because he believes they tarnish his image.He is located in a country where same sex relationships are illegal and the student is studying a country where sexuality is not an issue.The supervisor can not endorse the student 's pass because the student identified practices that are in conflict with the supervisor's beliefs.As a result the supervisor is continuously demanding changes to he research questions and methodology in order to force the student indirectly to remove his observations or report the students so that they can be tried for committing an illegal practice. what can the student do to have his doctoral thesis endorsed because external examiners have already marked and declared he passed.Of course the student had to correct what the external examiners picked as sticking issues. This has to be done in agreement with the supervisor.