From Createquity:

In response to critiques about standardized tests as an evaluation measure, some education reformers have suggested substituting portfolios, which focus on performance assessment. Rather than choosing among pre-determined options, students must construct an answer, produce a product, or perform an activity. States including Maine, New Hampshire, New York, and Ohio are starting to adopt performance assessment systems to meet the new Common Core State Standards. There are clear challenges to implementing a portfolio system on a large scale, such as the ability to reliably compare among schools, districts, and states, but the authors suggest that the Advanced Placement model, where large numbers of essays are graded by a panel of readers, might be one solution.