Despite its clear implications, our study has several limitations. We may have missed a very low base rate ODD taxon. However, this possibility is unlikely given the size of the samples and the expected base rate of ODD. Although a strength was the use of multiple informants (mother and teacher), thereby circumventing the issue of mono-informant bias, data were missing from one respondent for 398 of 969 (over 40%) of the children. Thus, the indicators in the child study were a mix of mother/teacher-report [with the only the highest rating considered for each item], mother-report only, or teacher-report only (the latter two taken indiscriminately because data from the other respondent was missing). Although the ODD items based on taking the highest rating at the item level (or taking the only item rating available in the event one was missing) yielded excellent internal consistency, such a finding is only a precursor for validity. Future research should continue to examine the latent structure of ODD using multiple methods from multiple informants to provide further evidence of the dimensional nature of this construct.
