Presented at the Annual Meeting of National Council on Measurement in Education (NCME) in San Diego, CA in April 2009. This presentation describes the methodology that was used with subject-matter experts (SMEs) to articulate the content and skills important in the domain, and then the iterative processes that were used to articulate the claims and evidence to represent the targets of instruction for AP courses, and by extension, the targets of measurement for the AP exams.