The development of the Conners 4 was comprised of three phases: (a) the conceptualization, initial planning, and item development phase; (b) the pilot phase; and (c) the standardization phase. The goals for developing the Conners 4 were to build upon the strong foundations set by its predecessor, while providing updates and refinements to enhance the structure, content, and format of the rating scales (for a breakdown of how much of the content from the Conners 4 full-length and short forms were unchanged, modified, and new when compared to the content from the Conners 3, see Tables 6.14 and 6.15, respectively). As a result, the Conners 4 not only preserves the core strengths of the Conners 3, but also presents a measure that better aligns with the test of ADHD for adults, CAARS 2 (Conners et al., 2022), and meets the standards for fairness and cultural sensitivity. The revised measure also includes updated and more representative normative samples and ADHD Reference Samples to better facilitate the diagnostic process. There is now greater alignment across Parent, Teacher, and Self-Report forms, modified and new metrics to capture possible invalid symptom reporting and responding, screening items for common clinical concerns with ADHD, updated and expanded content, and new scales to examine impairment and functional outcomes.