by Malcolm Gladwell
Read an excerpt:
...ent learned over the school year. And if he looked at the difference between a student's score in June and then in the following September, he could see how much that student learned over the course of the summer. In other words, he could figure out—at least in part—how much of the achievement gap is the result of things that happen during the school year, and how much it has to do with what happens during summer vacation. Let's start with the school-year gains. This table shows how many points students' test scores rose from the time they started classes in September to the time they stopped in June. The "Total" column represents their cumulative classroom learning from all five years of elementary school. Class 1st Grade 2nd Grade 3rd Grade 4th Grade 5th Grade Total Low 55 4...