Social research is inherently entwined with the researchers’ own personal bias and values. The aim of this case study report is to consider approaches to teaching postgraduate education researchers how to recognise and advise of this in their research. A key aspect in teaching social science is the need to impart the knowledge for students to advise of the partial nature of their research (Butler, 2005). Using critically reflexive observations gives the researcher a method of advising how knowledge gained from their research has been affected and formed by their own position in the research (Finlay, 2003). It conveys the power relationships of the supervisor, researcher and participants in the research (Bondi, 2009), and underpins the nature of the researcher’s personal perspective. Students are reluctant to be critically reflective (Adriansen and Knudsen, 2013) as they can feel threatened by the reflective process (Borochowitz, 2005), feel they can sit apart or outside their research and write without bias (Gursti-Pepin and Patrizio, 2009) and/or feel critical reflection may damage their research findings, (Fook and Askeland, 2007). The objective of this paper is to explore the effectiveness of an approach to overcoming this reluctance to reflect developed during a research module in Zambia. Here students discussed personal bias by likening it to an encounter with a dangerous, unseen animal, and identified similarities with a hippopotamus. This animal is difficult to tame, dangerous, hard to deal with, can remain hidden for a long time, appears unexpectedly, cannot be ignored, and awareness the main defence. Anecdotal reports suggested this improved the early adoption of critical reflexivity in the research of this group. This metaphor was then used as a key discussion point on a postdoctoral education programme in the UK and investigated using focus group discussions before after class. The investigation was based on the following questions: How would you define personal bias? What effect will your own personal bias have on the results of their research? How would you deal with personal bias? What role might critical reflexivity play in your research? Did the hippo metaphor aid their understanding of personal bias and the need for critical reflexivity? If so how? On analysis of the replies students reporting a greater understanding personal bias, recognition of the importance of being critically reflexive, and felt the metaphor of the hippo had been instrumental in their understanding.