Int. J. Environ. Res. Public Health 2009, 6 1271 completely agree. For the purpose of analysis the variables were dichotomized (completely agree/agree versus no opinion/disagree/completely disagree). A test retest study, with a 4-6 day test retest interval, was done in a small convenience sample (acquaintances and colleagues with young children; n = 24). Test-retest Kappa statistics of the dichotomized variables ranged between 0.36 and 1.00 with an average of 0.74 (eight items = almost perfect agreement (> 0.80); nine items = substantial agreement (0.61-0.80); three items moderate agreement (0.41-0.60); one item = fair agreement (0.21-0.40)). 2.3. Analysis Multilevel logistic regression analyses were carried out to investigate differences between mothers, fathers, and teachers completing the questionnaires and to investigate a potential association of parents‟ opinion with their education. For the latter, the education of the respondent was categorized into high = bachelor or master or low = secondary school or less; analyses controlled for the gender of the responding parent. Finally, associations of school food policy satisfaction with each of the opinions about the own school food policy were investigated. We anticipated that our individual responses (the opinions about the school food policy) would be clustered by school; therefore, our parents and teachers at level 1 were nested within schools at level 2. The independent variables are presented as dummy indicator variables contrasted against a base category. P-values < 0.05 are considered significant. MLwiN software version 2.02 was used to calibrate the models using second order Predictive/Penalized Quasi-likelihood (PQL) approximation procedures. 3. Results 3.1. Participants Study 1 Study 2 Fifty principals completed the school questionnaire (89% of the participating schools). Of the 90 teachers approached, 70 returned (78%) a completed questionnaire. All teachers were women. Of the 1,432 children approached for participation, 884 (61.7%) returned a completed questionnaire: 84.8% were completed by mothers (M), 11.2% by fathers (F), the remaining 4% were completed by others or the information was lacking. Forty-eight and a half percent were boys, 50.6% girls, for 0.9% the information was missing. Parental education was as follows: mothers: 51.2 % low education, 46.2% high education, 2.6% missing; fathers: 55.3% low education, 37.4% high education, 7.2% missing.