We know that validity, reliability, classification accuracy, statistical bias, and sample representativeness are important considerations when reviewing screening tools, but what do they actually mean? These five screening one-page documents provide a brief overview of each of these areas that are used on the NCII Screening Tools Charts. These one-pagers include a definition, examples, and information on why that particular standard is important for understanding the quality of screening tools. Companion infographics are also available.