The application of measurement principles to qualitative data around scientific understanding not only reveals important problems for teachers and curriculum design; it highlights a pedagogical solution. Panizzon & Bond (2006) demonstrated that students’ understandings of diffusion and osmosis remained similar across the high school–university transition, in spite of obvious differences in coursework and pedagogy. In another study, Stanbridge (2001) used Rasch scaled SOLO-based measures to reveal that while constructivist teaching improved Year 9 students’ understandings of particle theory, learners’ levels of cognitive development placed a ceiling on their conceptual growth in chemistry. The mismatch between high school and university science curricula and the capacity of students to make personal meaning of scientific concepts creates a pedagogical impasse. A possible solution was identified in the research of Endler and Bond (2001a,b; 2006) where measurably important gains in achievement and cognitive development were demonstrated for high school students experiencing the Thinking Science program. This paper provides a summary of these three case studies with particular attention to the pedagogical implications of these findings for science teaching.