Much research indicates the importance of interactional experience for young children in developing their competence. In particular sensitivity in interaction has been associated with beneficial developmental outcomes and is often regarded as a central component of good quality child care. This study considers some alternative ways of measuring the sensitivity of caregivers. Thirty professional caregiver-infant dyads were observed in three different situations: in the laboratury during free-play (1), during a task (2) and at the nursery itself while caring for 10 infants with a colleague (3). Results indicated that their sensitivity was highest in situation 1; this score was significantly related to the sensitivity score in situation 2 and to that in the nursery. The sensitivity scores in situations 2 and 3 were not significantly related. The data support the view that sensitivity is subject to contextual influences and that researchers need to think carefully about the when and where of such measurements.