Sandra Myers’s explication of test validity and reliability introduces two important elements of test design. As she explains, test developers must ensure that tests are reliable in that they will report similar results even when administered to new groups of students over a period of time. Unclear directions or flawed test items can make test results inconsistent, but test validity can determine how well an assessment measures what it is supposed to measure. Maureen McMahon reviews the field of psychometrics, the study of tests and measurements that attempt to sort and categorize people’s abilities, aptitude, and behaviors. She goes on to describe classical test theory as “a branch of psychometrics that aims to predict the outcome of entire tests or the response of specific test items,” which can also be helpful in determining a test’s reliability. Myers discusses item response theory, a mathematical prediction of students’ test performance that can enable more accurate tests in the future. She then reviews the use of rubrics in classrooms and how they offer formative assessment that outlines clearly what students are expected to learn by the end of the course or school year.