Abstract: Portfolios are believed to unobtrusively document events through classroom artifacts gathered by instructors and support personnel (Habib & Wittek, 2007; Zepeda, 2002). Since the mid 1980s many teacher education programs turned to portfolios to document teacher practice and growth; promote inquiry, reflection, and skill development; and assess competency (Dhonau & McApline, 2005; Hallman, 2007; Rickards et al., 2008; Wetzel & Strudler, 2005). [...]teachers and reviewers must rely on evidence quality characteristics (e.g., relevance, credibility, proximity, abstractedness) when examining portfolio arguments and assumptions.