Pennsylvania officials must do more than voice concern over reports that 60 schools, half of them in Philadelphia, may have cheated on standardized exams.

Full investigations are in order, and it cannot be left to the local districts to conduct the probes.

State Education Secretary Ronald Tomalis said he plans to order further review and possible action. But there is no reason for Tomalis to delay intervention. Swift action is needed to restore integrity and credibility to the system.

A report by state education officials that analyzed Pennsylvania schools for possible testing improprieties on the 2009 state examinations has provided ample evidence for a more aggressive approach.

The report flagged potential cheating in schools across the state, based on statistically unlikely scores, response patterns, and erasures. The findings were deemed evidence that the scores occurred as a result of something aberrant or unusual.

The report did not make any direct accusations. It cited 22 regular Philadelphia public schools and seven charter schools for statistical irregularities. The other schools cited are mostly in suburban districts.

Some of the districts have conducted their own probes. But the vested interest those districts have in the outcome reduces the credibility of their investigations.

The Philadelphia district said it would reopen its investigation, if asked. But the state cannot rely on any district to do the thorough investigation needed to clear up whether there was cheating.

A spokesman for Tomalis said the state plans to take a closer look at the scores that were flagged in the data forensics technical report, but it was not clear how the review would proceed.

Pennsylvania can avoid the mistakes made by New Jersey officials investigating alleged cheating in Camden several years ago.

New Jersey officials said test scores were manipulated by "adult interference." But a promised investigation left unanswered nagging questions about exactly how the test rigging was orchestrated in the South Jersey district. Neither the state nor the district ever held anyone responsible.

High-stakes standardized testing mandated by federal law has put increasing pressure on educators. A widespread cheating scandal in Atlanta has implicated nearly half of the city's schools, and some teachers could go to jail.

Pennsylvania must get to the bottom of its test-score irregularities and not leave that chore to the districts. Only then can the public have confidence in the system.