1. In a quasi-experimental study, the participants are not randomly selected. Since in this study, residents of the first and second floor are selected spefically not randomly, this is quasi-experimental study.
2. The greatest advantage of this study is that this study is less expensive and require fewer resources compared with individual randomized controlled trials (RCTs) or cluster randomized trials.
3. Internal validity is valid as the degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables. External validity is not fairas the results from this study cannot be applied (generalized) to other situations, groups or events because this is a non-randomized experiment.