reinforce the information obtained by observing students as they engage in the activity or by talking with them.
The occasions to sit with, converse with, question, and listen to the students gave Ms. K and Ms. R the opportunities to employ powerful questioning strategies as an assessment tool. When teachers ask salient open-ended questions and allow for an appropriate window or wait time (Rowe, 1974)—they can spur student thinking and be privy to valuable information gained from the response. Questions do not need to occur solely in whole-group discussion. The strategy can occur one-on-one as the teacher circulates around the room. Effective questioning that elicits quality responses is not easy. In addition to optimal wait-time, it requires a solid understanding of the subject matter, attentive consideration of each student's remarks, as well as skillful crafting of further leading questions. In the vignette, Ms. K needed to be aware of the existence and causes of algal blooms in order to ask questions that may lead her students down productive paths in exploring them.
The close examination of student work also is invaluable, and teachers do it all the time. When looking at work, it is important to ask critical questions, such as “For what does this provide evidence? ” “What do they mean by this response?” “What other opportunities did the child have to demonstrate knowledge or skills?” “What future experience may help to promote further development? ” “What response am I expecting?” “What are the criteria for good work?” “What are the criteria for gauging competency?” These are just a few of the questions that can spur useful analysis. Continued and careful consideration of student work can enlighten both teacher and student.
Like Ms. K and Ms. R in the vignettes, teachers are not concerned with just one dimension of learning. To plan teaching and to meet their students' needs, they need to recognize if a student understands a particular concept but demonstrates difficulty in applying it in a personal investigation or if a student does not comprehend fundamental ideas underlying the concept. Specific information regarding the sources of confusions can be useful in planning activities or in initiating a conversation between students and the teacher. An array of strategies and forms of assessment to address the goals that the student and teacher have established allows students multiple opportunities to demonstrate their understandings.