Studying metacognition brings with it many challenges. The challenge of researching metacognition is exacerbated when research, (a) moves from clinical or highly structured settings, those associated with much research in this field, to more naturalistic contexts with less structure, and (b) begins in previously unexplored settings and social contexts with little, if any, existing literature related its study within such settings. We use the metaphor of "prospecting" to characterise a qualitative methodology that employed a hermeneutic dialectic process to explore the metacognition of parents and their children as they interacted in the naturalistic setting of a science museum. We explore and explain the dialectic hermeneutic questioning and decision making processes we employed and how the research proceeded over 4 days and 14 cases as part of our detailed methodological reflection. Our aim is to inform future research in metacognition, or other under-researched learning phenomenon, using interpretive methods in such settings, and to provide examples of the decisions and thinking that shaped our study's progress.