Teacher candidates bring many beliefs and interpretations of mathematics teaching and learning at the start of their teacher preparation coursework (e.g. methods courses, field experiences, assessment). Well-prepared beginning teachers in many instances requires programs and designed experience to breakdown unproductive beliefs and/or improve dispositions to align to best practices and equitable dispositions for the teaching and learning of mathematics. Our study focused on developing and validating two rubrics to evaluate teacher candidates' talk during live discussion forums in the first month of their initial teacher preparation program coursework with the intent to inform to varying degrees, where teachers candidate talk is situated (or not) in alignment to foundational readings and productive beliefs. Early validity evidence for rubric use is presented with suggestions for informative use and practice. [For the complete proceedings, see ED630210.]