Three types of instruments were designed and used in the study. This study is triangulation which includes multiple data sources, multiple methods and multiple theoretical schemes because to check the validity of the study. Firstly, open-ended questionnaires were used to assess the knowledge of students in relation to the topic childhood diarrhoea. Secondly, classroom observation tools were used to obtain first hand information for the researcher about the process of session delivery. Thirdly, session evaluation tools were used to get information on how much the topic was relevant and interesting to the students. It helps at the time of data analysis .The questionnaire surveys are often subjective and impressionistic, however, it does not mean that questionnaires are invalid. There are three ways in which the subjectivity can be minimized through triangulation. The triangulation technique is used to map out the complexity of human behavior from more than one standpoint by making use of multiple methods. Methodological triangulation combines more than one method to study the same issue. The rationale behind this strategy is that the flaws of one method are often the strength of the other, and in combination, one can achieve the best of each while overcoming their individual deficiencies. Since data generated through one method may present a biased picture of reality, confidence can be achieved when different yield covering evidence (Adhikari,& Jayawickramarajah,1996).