The study sample will include six Group 1 (no PWP intervention) schools and six Group 2 (With PWP intervention) schools, with 60 students per school for a total of 360 students in Group 1 schools and 360 students in Group 2 schools. The sample size among the 12 schools was calculated assuming an intra-cluster correlation coefficient of p=0.01, this design will provide 80% power (Donner and Klar, 1996) to detect a medium effect size (Cohen 1992) of 0.50. The sample size will be increased by 15%, to 414 for intervention and control, to account for attrition.