It would be a mistake to view IDA as a wholly new methodology. Pooled data analysis has a long history and other techniques for combining raw data have also been introduced in the literature such as mega-analysis (another approach to the statistical analysis of individual raw-scores from previous studies; McArdle et al., 1998) and individual-patient data analysis from the field of medicine (e.g., Ioannidis et al., 1999). Despite these options, research studies in clinical psychology rarely use pooled data analysis (though see Lorenz et al., 1997; McArdle et al., 2000; and McArdle et al., 1998). Nonetheless, we believe that these techniques, and IDA in particular, offer unique advantages to the field of clinical psychology that may help mitigate endemic problems in studies of abnormal and clinical behavior (Curran & Hussong, 2009).
