In this paper, I picked up Donna Santman's practices, and examined the way of assessment to help students to be independent readers. Through some examination, I clarified the aspects of two types of assessments she used. One is "early assessment" for figuring out the student's condition before she conducted Reading Workshop. This "early assessment" is important to identify students'misconception of reading, and to take shape comprehension strategies for revising student's misconceptions. The other is conducted through conversation between teacher and students by using rubric in the conference. In this conversation, teacher assess the student's use of comprehension strategy, and evaluate the outcomes that students produced. Finally, I pointed out that it was important to examine the vision of assessment, and to conduct ongoing assessments based on the vision because such assessments led to evaluate student's outcomes and the effects of comprehension instruction.