Animating equity in teaching and learning depends on teacher dispositions--orientations to self, others, and society that underlie how we think and act. Teacher dispositions are virtues or qualities of moral character that modify the ways we interact with students and educator colleagues. Although interest in "measuring to improve" teaching and teacher education has grown recently, most measures lack validity evidence for practical usefulness. Integrating Messick's "unified validity framework" with Janssen et al.'s notion of "practicality" (as face validity), we find through an iterative, mixed-methods analysis of interviews with equitable educators and survey responses from teacher candidates that incorporating recognizability, relevance, and feasibility concerns of equity disposition concepts (i.e., Social Awareness, Meekness, Advocacy for Students) within survey items enhances item-to-factor structure of a self-report measure. We discuss implications (1) to develop and appraise formative measures and (2) to support teacher learning and development to become equitable educators.