Observing Instructional Practice: Can We Consistently Measure Teaching Quality Constructs?

Classroom observation systems can be an important tool for understanding teaching quality. However, the wide range of possible lessons that can be observed raises concerns about whether fixed observation rubrics can measure the intended teaching quality constructs equally well in each lesson. This paper argues for exploring measurement invariance across lessons in observation systems, adopting an understanding of measurement invariance that emphasises the alignment between a theoretical construct and the measurement of that construct. We conceptualise teaching quality using the Protocol for Language Arts Teaching Observation (PLATO). PLATO’s focus on individual items is misaligned to traditional measurement invariance approaches, so we emphasise the importance of detailed, qualitative considerations of how rubric operationalisations of a construct may or may not capture the intended teaching quality construct equally well across lessons with different characteristics. We discuss the affordances and limitations of this way of considering measurement invariance and argue for the importance of ensuring measurement invariance across lessons.