All parents want their child to perform well in school. However, three new studies suggest this may not happen if the child watches too much television. The studies were published this month in the Archives of Pediatric and Adolescent Medicine.

Researchers at Stanford University in California and Johns Hopkins University in Maryland carried out one study. They examined the test scores of three hundred fifty students who were about eight years old. More than seventy percent of these students reported having a television in the room where they sleep. These students performed between seven and nine points lower on math, reading and language tests than students without televisions in their rooms.

Scientists at the University of Washington carried out the second study. They examined information on about one thousand eight hundred students. The researchers found that too much television before age three was linked to lower reading skills by age six.

The study also found that six and seven-year-old children had poorer short-term memory if they had watched a lot of television in their earliest years. However, children who watched TV after age three seemed to be better able to sound out and say words.

Researchers at the University of Otago in New Zealand did the third study. They followed more than one thousand people born around nineteen seventy-two. They found that those who watched the most television between the ages five and fifteen were the least likely to finish high school and college by age twenty-six.

A report critical of the three studies also appeared in the Archives of Pediatric and Adolescent Medicine. Deborah Linebarger of the University of Pennsylvania helped write it. She said the studies measured only the time children spent watching television and not what programs they watched. Her research has shown that quality educational programs can help children learn.