Rating scales allow teachers to assess students' behaviors, skills, and strategies by indicating their degree or frequency. There are several types of rating scales including numerical, descriptive, graphical, and comparative. A commonly used rating scale is the Likert scale, which can have 5, 7, or 9 points and asks people to indicate their level of agreement. Rating scales standardize qualitative and quantitative judgments about performance but can also be subjective and biased depending on the rater. They are useful for periodically evaluating students on traits but may overlook some behaviors.