Failing Sideways is an innovative and fresh approach to assessment that intersects writing studies, educational measurement, and queer rhetorics. While valuing and representing the research, theory, and practice of assessment, authors Stephanie West-Puckett, Nicole I. Caswell, and William P. Banks demonstrate the ways that students, teachers, and other interested parties can find joy and justice in the work of assessment. A failure-oriented assessment model unsettles some of the most common practices, like rubrics and portfolios, and challenges many deeply held assumptions about validity and reliability in order to ask what could happen if assessment was oriented toward possibility and potential. Working to engage a more capacious writing construct, the authors propose queer validity inquiry (QVI) as a model for assessment that values failure, affect, identity, and materiality. These overlapping lenses help teachers honor parts of writing and learning that writing studies faculty have struggled to hold onto in a world overly focused on quickness and efficiency in schools. Through programmatic and classroom examples, Failing Sideways privileges what is valued in the classroom but traditionally ignored in assessments. Reimagining what matters in the teaching and learning of writing and using assessment data differently, this book demonstrates what writing can be and could do in a more diverse and just world.