The CAARS 2 Normative Sample is representative of the U.S. and Canadian populations. The Normative Sample contains proportions of key target demographic variables described in this chapter (i.e., age, gender, race/ethnicity, region, and EL) that are consistent with U.S. and Canadian census proportions. Furthermore, the Normative Sample contains generally representative proportions of individuals with a mental health diagnosis to better reflect the actual general population, which includes persons with and without such diagnoses. The observers who rated individuals in the Normative Samples reflect a diverse population. In addition to the Normative Sample, an ADHD Reference Sample was collected to represent individuals with ADHD, including those with co-occurring clinical diagnoses. Using these standardization samples, standardized scores were computed via continuous norming to convert raw scores into T-scores and percentiles that account for the age of the individuals being rated, as well as additional standardized scores that can also account for the gender of the individual being rated. Empirical percentiles were calculated to accurately describe the skewed shape of the distribution of many of the CAARS 2 scales for the Normative Samples, and theoretical percentiles were calculated for the ADHD Reference Sample.