Thus the form that assessment takes is significant. The form and content of assessment should be consistent with the intended purpose. Underlying this guideline is the technical notion of validity. Technical features are discussed later in this chapter. Validity centers on whether the assessment is measuring or capturing what it is intended to measure or capture. If content understanding is the goal, it is necessary to design an appropriate assessment that would tap into that dimension of their understanding. If the ability to design an investigation is the goal, it is necessary to provide the opportunity for a student to demonstrate her ability to do such an activity. Validity is not, then, an inherent property of an individual assessment; rather, the interpretations drawn from the data and the subsequent actions that ensue are either valid or invalid. Choices for the form of the assessments are extensive and should be guided by the goals set for student learning. To find the direction for best use of the assessment data, a teacher or student gathers data in the course classroom activity by asking questions, such as “What does this information tell me?” and “How can I use it to further learning and improve teaching? ” and “What other types of data should I be looking for to help me make sense of this information?”
From Stiggins' (2001) book, Student-Involved Classroom Assessment, Figure 3-1 offers questions to consider when designing, selecting, or implementing an assessment. After first advising teachers to set clear and appropriate targets—or learning and performance goals—and convey these targets to their students, he stresses the importance of selecting appropriate methods and of taking care to avoid invalidity and bias.