Over the last two decades, significant advancements have been made in conceptualizing, operationalizing, and measuring teaching quality. The development of observation systems has enabled a more targeted and systematic measurement of features that reflect teaching quality across contexts. This chapter presents the results of a study that explores instructional practices and a framework by drawing on video data from lower secondary mathematics, language arts, and social science classrooms in all Nordic countries. It discusses how systematic coding can help generate broad pictures of instructional practices and demonstrates how a common framework, such as the Protocol for Language Arts Teacher Observation (PLATO) manual and the conceptual language it provides, might work in a Nordic context. PLATO reveals general patterns in terms of scoring the features that characterize teaching quality within and across subjects, countries, and classrooms. PLATO scores are high for elements related to the classroom environment, low for those related to instructional scaffolding and explicit instruction, and at a generally moderate level for elements related to the representation of content and disciplinary demand. We identify patterns of PLATO scores across countries, classrooms, and subjects and discuss how observation manuals might serve as a tool for teachers’ professional learning.