Gazette Photo by John Ruch PATRICK’S DAY Gov. Deval Patrick has his easiest conversation of the day talking with children during a public forum July 26 at the Johnson Playground on Green Street. Among the JP residents questioning Patrick was Boston Public Schools teacher Erik Berg, who asked about the “mania for data and testing” in schools. “I personally stink at standardized tests,” said Patrick, saying that testing should have a role, but should not be central in schooling. Local state Sen. Sonia Chang-Díaz introduced Patrick, praising him for his support of in-state college tuition rates for undocumented immigrants.