Moreover, the authors should have provided the total number of the participants separately at the beginning of the section with important details such as their demographic information, age range, their previous backgrounds in the peer-led discussions. This is because these factors might be a threat that can change the findings. In the article, in Pauls’s class, there in no report of the student age, but their is a report indicating that they are in 12th grade. Students in Esther's class are in eighth grade, and there in no report of the average age. There is no report student grade and age in dera's class. In Alan's class, students are in 11th
grade, and their age ranges from 17 to 22 year. Pat teaches 10th-grade student, and their age is not reported.
Absenteeism, school attrition, and changes in schedules in Pat's class may be a threat to the internal validity of this study in that these factors may have affected the findings because it is mentioned that most of the focal group interview data come form four out of six focal students. In fact, their absence makes it very difficult to understand