Forget about standardized tests. Forget about weekly quizzes. Forget about homework. The most critical time for assessment is during daily in-class practice, when you can see sooner rather than later what students are struggling with and why they're struggling with it. It's only then that you can provide timely, differentiated feedback and remediation. (See Differentiated Instruction: A Practical Approach.)

Unfortunately, teachers often miss the chance to do this because they're assisting a few students at the expense of assessing all students. At the end of typical math lessons, for example, teachers assign practice problems for students to try on their own ("Independent Practice"). They then promptly help the first student whose hand shoots up. After two, three, and sometimes five or more minutes, they finally move on to another student.

Many students, meanwhile, sit idly as they wait their turn for the teacher's help. Some call out until the teacher signals or says, "One minute." Others raise their hands for several minutes, switching arms every so often to avoid fatigue. But eventually the bell rings or kids give up--and often act up. And because they never get the help they need with class work, they're unable to successfully complete homework. What's more, getting back to assessment, teachers prematurely conclude what the class as a whole does or doesn't understand (and why they don't understand something) based on what they've seen or heard from just a few students.

For these and other reasons, it's better to assess how all students are doing before you assist any students. At the same time, you don't want to leave kids hanging when they need help, so here are a few ways to maximize assessment time for you without sacrificing assistance time for them:

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• Assign students to mixed-ability groups, where they work at their own pace but can ask each other for help as necessary. Think of this as "Independent and Interdependent Practice" rather than "Independent Practice."
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• Only assist students when they've exhausted all other available resources--notes, textbooks, technology, each other, etc. (See When Helping Students Hurts Studentsfor more on teaching and reinforcing resourcefulness.)
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• Establish an expectation of students to move on to another question if they've used all other resources and you're unavailable.
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• Be sure students understand the directions before you have them start an activity, since you never want to be clarifying what they should be doing when you can be assessing how they're doing it. (SeeDirections for Giving Directions.)