Without treatment, 50 percent of retinopathy cases improve to better than legal blindness, or 20-200 vision.

Within a few years, their incomes rose 20 percent and their English improved greatly.

Through much of that year, only 10 to 15 percent of the public thought things were improving.

Forty-four percent improved faster than the state averages for each grade level.

After six weeks in summer school, 27 percent, or 1,700, had improved enough to move on to the fifth grade.

Eighty to 90 percent of people with severe depression, according to the the institute, improve drastically.

Ninety percent of people improved to at least a reasonable degree.

After a six-week summer course, 27 percent, or 1,700, had improved enough to avoid being retained.

Edison has also calculated that more than 80 percent of its schools have improved on standardized tests.

Experts estimate that 30 percent of all patients getting placebo treatment today improve.