- All participants and their parents or guardians completed all interview forms and instruments without missing data.
- None of the participants withdrew from the study.
- Almost equal numbers of gender were included in the study groups.
- The age and school grade distributions were not equivalent.
- A large number of the participants in the experimental group were 11 years old, while the majority of the control group was 8 years old.
- Because the age distributions were not equivalent, age was also treated as a covariate.
- 99% of participants were Buddhists.