Editing: research/abstract_eng/302.txt

The main purpose of this experiment was to study the effect of persuasive messages based on Kohlberg moral resoning theory on attitude change. In addition there were other independent variables, namely, familiarity with the persuasive messages, sex and rigidity. After the subjects had read the high moral reasoning messages or low moral reasoning messages or control messages, the attitudes and moral reasoning ability of subjects were then assessed. The sample consisted of 120 subjects of which 60 were males and 60 were females. They were secondary school students at Huathapanwittayakom school in Ubonratchathanee province. These students were third stage users of moral reasoning. All subjects were assigned randomly to either one of the two experimental groups or a control group. Each group of students consisted of 10 males and 10 females of highly rigid personality, 10 males and 10 females of low rigid personality with the total of 40 students. The first and the second experimental groups read high leveled and low leveled moral reasoning messages. Both of the high and low messages were on the same four issues, two of which were highly familiar topics ( issues on "teacher" and "snake" ) and two less familiar ones (issucs on "buying Thai goods" and "touring foreign countries") while the control group read controlled messages. Then the attitudes tomards the 4 issuse were assessed by two different attitude tests. The Osgood' s method and the Likert's method were used to measure the affective compenent and the behavior intention compenent respectively. There were five important findings. First; the main effect of the persuasive messages was found on attitudes. The subjects whoread the high and low moral reasoning messages had significantly higher attitude scores on the 4 stories than the subjects who read the control message. When the attitude towards individual issue was examined it was found that the affective compenent of attitude towards " teacher" varied according to the levels of the messages received. In other words, the students who received high level message were more favorable towards "teacher" than the control subjects. These findings clearly supported the major hypothesis of this study. On the other hand, the behavior intention component of attitude towards teacher did not differ among the three groups of subjects. The results on 3 other issues were the same as that of allissues combined. Secondly; when attitude scores were analyzed according to the more and less familiar stories. The two types of contents yielded different results only when the affective component of attitude was analyzed. In more detail, the low leveled readers showed more favorable attitudes towards the issues than the control groups only when the less familiar issues were used, otherwise, the high and low message groups were equally favorable. Thirdly; when examined the main effect of sex, male and female students showed no difference on the two types of attitude. Furthermore there was no interaction between sex and persuasive messages. When divided male and female students on comprehension scores of persuasive messages in the low comprehension group, male students showed significantly higher affective component of attitude than female students. In the high-comperhension group, female students showed significantly higher behavior intention towards buying Thai goods than male students. Fourthly; There was no difference in both components of attitude of the high and low rigidity subjects. There was also no interaction between rigidity and levels of moral reasoning messages. Finally; The results showed that the group of students who had read the messages pertaining to different levels of moral reasoning, were not different in moral reasoning ability after reading the messages. This experiment showed that the persuasive messages with high level of moral reasoning could greatty affect students' attitude change, especially or the story of "teacher". Among the students who highly comprehened the persuasive messages, the female students showed greater change in behavior intention than male students, especially on story of buying Thai goods. Thus there was a story implication that this type of persuasive technique could lead female students to change their behavior as well.