The sample of this study are parents aged 25-50 years old that lives in Brgy. Sampaloc IV, Dasmariñas Cavite, who have at least one child that was given immunization beforehand. The researchers chose those samples as they believe that the parents have a prior knowledge on the particular events that is appropriate for study.
In this study, the researchers used purposive sampling. Purposive sampling is a non-probability technique that involves the conscious selection by the researcher of certain people to include in a study. The researchers applied heterogenous sampling, it is a type of purposive sampling used to capture a wide range of perspectives which fits the criteria of the respondents that is related to the phenomenon the researchers are interested in. By condition, the researchers chose parents aged 25-50 years old who have at least one child regardless of their gender, educational attainment, and occupation. These units may exhibit a wide range of attributes, behaviors, and experiences. The basic principle behind this approach is to gain greater insights into a phenomenon by looking at it from all angles. This can help the researchers to identify common themes that are evident across the samples. The researchers believe that this approach is appropriate because according to Black (2010), obtaining a representative sample by using a sound judgment will result in saving time and money. The main goal of purposive sampling is to focus on particular characteristics of a population that are of interest, which will best enable the researchers to understand their perception.