This article describes a means of evaluating early years classrooms from the perspective of the child's experience. Nine key themes, such as motivation and independence, are identified as representing significant aspects of a high-quality environment for learning. The manner in which these manifest themselves in relation to the three elements of the interactional triangle&emdash;the children, the adults, and their physical environment&emdash;is assessed by means of an observation schedule called the Quality Learning Instrument (QLI). The paper illustrates the design and validation of the instrument with data from a project involving observations of classroom practice in Northern Ireland primary schools and Danish kindergartens. It describes how judgments made using the instrument can be triangulated or "calibrated" against the judgments of experts not connected with the data collection. The article concludes with the argument that the instrument may be successfully used to provide a basis for external quality assessments or as a means for early years teachers to reflect on the environment for learning that they generate in their own classrooms.