Recommendations for Hart Banach

1. Since the study lasts for quite a long time, quite a few subjects might quit from the study. Please keep a detailed record about the reason why they intend to quit, since these information plays an important role in our statistical analysis of missing data.

2. As we know, for general treatment and control study, the subjects themselves have no idea of which group they are divided into, just as we have come across in acupuncture study. For this study, the researcher seems to pay little attention to this point. In my opinion, this design might lead to some bias, which means difference produced by other factors, rather than treatment and control.

1. As the main objective of the study is to make some necessary steps in the policy implementation, so I think, it would be better to take more schools in different areas rather than one (stratified sampling).

2. The subjects should be selected using probability sampling procedure not subjective sampling.