This chapter describes the development and psychometric properties (reliability, validity, and fairness) of the Conners 4th Edition Short (Conners 4®–Short). The Conners 4–Short aims to assess core and associated symptoms of, and impairments related to, Attention-Deficit/Hyperactivity Disorder (ADHD) with more brevity than the full-length version of the test. Short forms can improve efficiency, decrease administration time, and reduce the cognitive load that can occur in long form tests (Maloney et al., 2011; Pfeiffer et al., 2011). This chapter details the development of the Conners 4–Short, including item selection, score creation, and the psychometric properties of the shortened measure. Note that the Conners 4–Short also includes the Negative Impression Index (see chapter 6, Development, for details about the creation of this index) and the ADHD Index (see chapter 12, Conners 4–ADHD Index)

Although the shortened forms are derived from the full-length form, the psychometric properties of the full-length forms are not transferable to abbreviated versions of a test, even when the correlation between the two is high (Smith et al., 2000; Ziegler et al., 2014). Therefore, the Conners 4–Short scales were examined using the same methodology of assessing evidence for reliability, validity, and fairness as the full-length version, as the Conners 4–Short is designed to be analogous to the full-length Conners 4.