Fourth-grade students in charter schools routinely outperformed their peers in nearby public schools in English and math, according to a study released yesterday by a Harvard University professor.
The study, which counters other recent reports that charter students fare no better than public school pupils, found that compared with students in the nearest district public school, charter school students were 4 percent more likely to be proficient in reading and 2 percent more likely to be proficient in math nationwide.
Charter school students in Massachusetts did even better, outscoring district public school students by wider margins than the national average.
According to the study, 7.1 percent more charter school students in Massachusetts scored proficient in reading and 7.3 percent more scored proficient in math compared with students in the nearest district school.
The authors of the report wrote that it is too early to draw sweeping conclusions, but ''the initial indications are that the average student attending a charter school has higher achievement than he or she otherwise would."
The study, conducted by professor Caroline M. Hoxby, focused on reading and mathematics achievement based on standardized state test scores. Charter school students make up only about 1.5 percent of US students.
Charter school supporters seized on the study, saying that it bolsters their case. Opponents said the way the study was conducted is faulty. Comparing a charter school to the nearest public school ignores the fact that many charter schools draw students from large geographic areas.
''It has absolutely zero relevance in Massachusetts," said Bob Duffy, a spokesman for the Massachusetts Teachers Association. ''Charter schools in Massachusetts draw from multiple communities. Comparing a charter school to the closest school to it is not statistically relevant. Charter schools are not neighborhood schools."