Abstract
Optimism is one of the key points in positive psychology. The basic element of optimism is the reformulated explanatory style for events. The optimistic explanatory style can help people to view events healthily and keep the power to go forward. The purpose of this study is to develop Secondary School Students' Explanatory Style Questionnaire based on the experience of life with secondary school students. The concept of the explanatory style in the study is multi-dimensional. The explanatory styles of the questionnaire includes four subscales. The four subscales are "good events to permanent-pervasive cause", "good events to personal cause", "bad events to permanent- pervasive cause", and "bad events to personal cause". The questionnaire has 30 items, each of which consists of a hypothetical good or bad event and two possible causes of the event. Respondents pick the cause from the pair that better describes why the event occurred. The students selected as participants are from 29 secondary schools. The participants includes 264 derivation samples and 2,760 replication samples. Cronbach's alpha coefficients of the questionnaire range from .384 to .587. In the confirmatory factor analysis, the Goodness-of-Fit of the questionnaire is good. The factor loadings are significant.