The survey data were collected from a random sample of 496 ninth grade students in 15 probability proportionate multistage cluster classes in Taichung City and County, Taiwan in 2005.

• 本研究资料得自2005年台中县市的496位依县市接近等比例、乡镇市区及学校不重复原则的15个接近等比例、丛集随机班级样本。