Background: This article presents a critical reflection on the application of the ‘researcher as instrument’ concept within a study employing the nominal group technique. Twelve community-dwelling older adults were recruited to generate a list of items for a new patient-reported outcome measure on perceived ability to recover balance. The ontological position and epistemological stance of the first author are presented to provide a philosophical context of his lens and biases of his reflection. Aim: The article aims to share reflective insights into the process of taking the role of researcher as instrument, to highlight the concept’s strengths and limitations for other researchers and demonstrate how it is applied from the perspectives of a physiotherapist conducting person-centred research with older clients. Conclusions: Essential practice skills such as reflectivity and reflexivity are necessary for a researcher as an instrument to build a trusting relationship with participants in person-centred research. Novice researchers should explore their philosophical orientation to develop their research methodology and methods. Implications for practice: Researcher as instrument can be applied to conduct the nominal group technique In person-centred research, researchers need to critically reflect on their roles to build trust with participants during the planning and delivery of their methods, being reflective and reflexive Consideration of one’s ontological and epistemological position allows growth in research learning