The significant difference among grade to dispositional optimism was found.The freshman had higher level of optimism than the sophomore and junior, and had lower level of pessimism than them. 3.

• 仅在年级变量上差异具有显著性，其中大一学生总体乐观水平显著高于大二和大三学生，大一学生的悲观水平显著低于大二和大三学生。