In his book "The Global Achievement Gap," Harvard Professor Tony Wagner maintains that a "learning walk" through leading suburban high schools will reveal what he calls the "hidden gap."

This hidden gap has to do with the ability of students to use critical thinking and problem solving, collaboration, adaptability, initiative and entrepreneurialism, effective oral and written communication, accessing and analyzing information, and curiosity or imagination. These "seven survival skills" make up the "gap" between what America’s students are learning and what they need to learn in an increasingly competitive global marketplace.

Check out the following two lessons observed by Wagner on one of his learning walks or classroom visits as they reveal two different tales:

Lesson 1 (11th Grade World History): Students are filling out a worksheet that requires them to answer questions on colonization, which countries colonized what areas when. They are using the maps in their textbooks as reference.

First, what is the purpose of this lesson? Is it to know facts? Is it to know relevant geography? Is it to know relevant dates? For these students in today’s technology-rich environment, this lesson is a "no-brainer." It can be accomplished through an Internet search with relative ease through collaboration by a few and shared with all.

Second, if every student is to work this lesson, could not this lesson be best executed through a homework assignment rather than take up valuable class time? Are we to spoon-feed students in hope that such truly educates? At best, this is a homework assignment to be turned in and responded to by the teacher. It is simple background knowledge for what should take up classroom time: what is colonization, why did it take place and with what results, and what were the geopolitical, economic, and moral arguments for its existence.

Lesson 2 (Algebra II): It is the beginning of the period, and the teacher is finishing up writing a problem on the board. He turns to the students, who are sitting in desk-chairs that are arranged in squares of four that face one another. "You haven’t seen this kind of problem before," he explains. "And solving it will require you to use concepts from both geometry and algebra. Each group will try to develop at least two different ways of solving this problem. After all the groups finished, I’ll randomly choose someone from each group who will write one of your proofs on one of the boards around the room, and I’ll ask that person to explain the process your group used. Are there any questions?"

There are no questions, and the groups quickly go to work. There is a great deal of animated discussion within all of the groups as they take the problem apart and talk about different ways to solve it. While they work, the teacher circulates from group to group. Occasionally, a student will ask a question, but the teacher never answers it. Instead, he either asks "Have you considered…?" or "Why did you assume that?" or simply "Have you asked someone in your group?"

Lesson Effectiveness: So, asks Wagner, "What are some of the design elements that make this Algebra II lesson effective?

First, students are given a complex, multi-step problem that is different from the ones they’ve seen in the past and, to solve it, they have to apply previously acquired knowledge from both geometry and algebra. Mere memorization won’t get them very far in this lesson; critical-thinking and problem-solving are required.

Second, students have to find ways to solve the problem, which requires some initiative and imagination. Just getting the correct answer isn’t good enough; they have to explain their proofs — using effective communication skills.

Third, the teacher does not spoon-feed students the answers; he uses questions to push students’ thinking — as well as the limits to their tolerance for ambiguity.

Fourth, because the teacher has said that he’ll randomly call on a student to show how the group solved the problem, each student in every group is held accountable. The group can’t rely on the work of one or two students to get by, and the teacher isn’t going to just call on the first student to raise a hand or shout out an answer. Teamwork is required for success."

As we move towards a renewed look at the kind of teaching and assessment often associated with No-Child-Left Behind, we must keep a tale of two lessons in mind: one requires memorizing, the other requires thinking. And, while factual content is important to a truly educated person, thinking is indispensable. Those who do the latter will rule the day.

Principals, curriculum leaders, and others must take their own "learning walks" in our schools. For teaching can no longer be a private act. The stakes are way too high.

I was once told by a wise school observer that "what gets monitored gets done, and what gets monitored and fed back gets done well."