The real power of performance assessment lies in the delineation of clear performance criteria, said Judy Arter, director of the assessment unit at the Northwest Regional Educational Laboratory (NWREL), at her packed conference session.
Performance criteria are "the basis on which you judge the quality of student performance on a task," Arter explained. Teachers' judgments about student work are always based on criteria, she noted. Teachers can either make these criteria crystal clear or make students guess what they are.
Spelling out criteria is not necessarily easy. People have clear criteria for what makes a good restaurant, for example, "but when we get to skills and knowledge, we're a lot fuzzier in our minds," Arter said. For example, what does it look like when students are good thinkers?
Arter emphasized the importance of communicating clear performance criteria to students. "If we want students to be able to self-assess, they have to know the criteria for what quality looks like," she said. One way to teach students to understand and use performance criteria is to have them read, score, and discuss anonymous sample papers, she recommended.
Where do performance criteria come from in the first place? Teachers can rely on the work of others, such as the "six-trait analytical model" for assessing writing developed by NWREL. Or groups of teachers can develop their own performance criteria, Arter suggested, by sorting student work into three piles based on quality (good, mediocre, poor), then writing detailed descriptions of the work in each pile. These descriptions can serve as the basis of scoring rubrics. A good scoring rubric is very descriptive, Arter emphasized: "That's the hallmark."
Teachers should engage students in defending the score they would give to their own work. "There's no such thing as a right score, only a defensible score," she said. "The essence of teaching criteria to students is so they can make these judgments too."