The current study utilizes the 2008 (T1) and 2009 (T2)
samples of the Monitor Study. Total response rate was 79% at T1, and 83% at T2. Non-response is mainly attributable
to entire classes dropping out due to internal
scheduling problems on schools; 13% of all classes did
not return any questionnaires at T1 and 12% did not
return questionnaires at T2. For the remaining classes,
the average per class response rate was 89% at T1 and
92% at T2. Twelve secondary schools participated in the
study at T1 and 10 secondary schools participated at T2.
Of these schools, eight participated in both years.